InTechOpen uses cookies to offer you the best online experience. By continuing to use our site, you agree to our Privacy Policy.

Medicine » Diagnostics » "Positron Emission Tomography - Recent Developments in Instrumentation, Research and Clinical Oncological Practice", book edited by Sandro Misciagna, ISBN 978-953-51-1213-6, Published: December 18, 2013 under CC BY 3.0 license. © The Author(s).

Chapter 8

PET – Assessment of Oncologic Treatment Response

By Inga S. Grills and Victor S. Mangona
DOI: 10.5772/57127

Article top


This is a 12-year-old female with a history of Stage IIB bulky nodular sclerosing Hodgkin lymphoma involving the bilateral cervical chain and mediastinum. She had achieved a complete response with 6 cycles of COPP-ABV chemotherapy. She then received a total radiation dose of 3060 cGy in 17 fractions of 180 cGy to the cervical and mediastinal lymph nodes. As seen in the serial PET/CT images (b-f above), the mediastinal and cervical lymph nodes responded well. However, by 28 months post-treatment, a left iliacus muscle lymph node became suspicious for lymphoma involvement (g – max SUV 5.0). By 31 months post-treatment, this node had increased further (h – max SUV 7.7).
Figure 1. This is a 12-year-old female with a history of Stage IIB bulky nodular sclerosing Hodgkin lymphoma involving the bilateral cervical chain and mediastinum. She had achieved a complete response with 6 cycles of COPP-ABV chemotherapy. She then received a total radiation dose of 3060 cGy in 17 fractions of 180 cGy to the cervical and mediastinal lymph nodes. As seen in the serial PET/CT images (b-f above), the mediastinal and cervical lymph nodes responded well. However, by 28 months post-treatment, a left iliacus muscle lymph node became suspicious for lymphoma involvement (g – max SUV 5.0). By 31 months post-treatment, this node had increased further (h – max SUV 7.7).
SUV kinetics after stereotactic body radiotherapy for NSCLC
Figure 2. SUV kinetics after stereotactic body radiotherapy for NSCLC
This is a 68-year-old male who presented with dyspnea and hemoptysis. Workup revealed a stage IIIB (T4, N2, M0) squamous cell carcinoma of the right lower lobe, 7cm in size invading the mediastinum. He received hyperfractionated intensity-modulated radiotherapy, 66 Gy in 1.5 Gy fractions twice daily.
Figure 3. This is a 68-year-old male who presented with dyspnea and hemoptysis. Workup revealed a stage IIIB (T4, N2, M0) squamous cell carcinoma of the right lower lobe, 7cm in size invading the mediastinum. He received hyperfractionated intensity-modulated radiotherapy, 66 Gy in 1.5 Gy fractions twice daily.
This is a 66-year-old male who presented with right shoulder pain. Workup revealed a clinical stage IIIA (T3 N1 M0) squamous cell carcinoma of the right upper lobe of the lobe with chest wall invasion causing destruction of ribs 2-4. He received hyperfractionated intensity-modulated radiotherapy 72Gy, 1.5 Gy twice daily, with concurrent and maintenance taxotere for 4 months. SUV nadir occurred at 6 weeks with evident local progression at 6 months.
Figure 4. This is a 66-year-old male who presented with right shoulder pain. Workup revealed a clinical stage IIIA (T3 N1 M0) squamous cell carcinoma of the right upper lobe of the lobe with chest wall invasion causing destruction of ribs 2-4. He received hyperfractionated intensity-modulated radiotherapy 72Gy, 1.5 Gy twice daily, with concurrent and maintenance taxotere for 4 months. SUV nadir occurred at 6 weeks with evident local progression at 6 months.

PET – Assessment of Oncologic Treatment Response

Inga S. Grills1, 2 and Victor S. Mangona1

1. Introduction

Positron Emission Tomography (PET), particularly with 18-Fluorodeoxyglucose (FDG), continues to define and expand its role in oncologic management. Beyond tumor size, as definable by computed tomography (CT), PET provides a measure of metabolic activity in tumors and is integral in initial workup for multiple disease sites including head/neck squamous cell carcinoma, non-small cell lung cancer (NSCLC), lymphoma, and many others. For head and neck cancers, FDG PET imaging facilitates early detection of persistent and recurrent head/neck squamous cell carcinoma after chemoradiotherapy, increasing deferral of surgical neck dissection to the salvage setting in many cases. In the setting of non-small-cell lung cancer, PET is further considered standard of care for radiotherapy treatment planning. Post-treatment PET has further shown to facilitate assessment of treatment response, with metabolic response seen on PET pre-dating CT-based radiographic response. Though routine post-therapy PET after definitive non-surgical management is standard management for head/neck squamous cell carcinomas, evidence to support this routine use for other subsites is lacking and thus currently not recommended for various organ sites including lung. This chapter herein discusses various PET imaging techniques and assessment variables that have been used to investigate assessment of response to oncologic treatment. In particular, assessment of response with early and late post-radiotherapy PET imaging for head and neck, NSCLC, rectal cancer, esophageal cancer, and lymphoma are discussed. Recent research involving on-treatment PET imaging as well as future work are further presented.

2. PET technique

2.1. 18F-FDG

PET is a medical imaging technique employing the unique parameters of decay of positron-emitting isotopes. Today, PET is routinely used in conjunction with computed tomography (CT) in a combined medical imaging device, PET-CT, allowing anatomic image correlation with the functional imaging obtained by PET.

A number of PET radiotacers have been used in oncology, though 18F-Flourodeoxyglucose (FDG) is FDA-approved and most commonly employed. Other agents including 18F-FMISO (18F-Fluoromisonidazole), 18FLT (18F-Fluorothymidine), 16b-18F-Fluoro-5a-Dihydrotestosterone (18F-FDHT), 60Cu-ATSM (Copper-diacetyl-bis(N4-methylthiosemicarbazone)), 18F-FES (16a-18F-fluoro-17b-estradiol), 11C-MET (11C-methionine), show significant potential to monitor the response to therapy before, during, or after therapeutic intervention[1].

18F-FDG chemically is 2-deoxy-2-18F-fluoro-D-glucose, a glucose analog. On 18FDG, the positron-emitting radioactive isotope fluorine-18 is substituted at the 2' position of the glucose molecule preventing glycolysis, which requires a hydroxyl group at the 2’ position. It has significantly increased uptake in tissues with increased metabolic activity, in particular, most malignancies [2]. With increased demand for gluose, tumors tend to have increased expression of glucose transport proteins at the cellular membrane as well as increased hexokinase [3]. With its relatively short half-life of 110 minutes, in tissues with rapid uptake, the 18F decay occurs primarily when trapped intracellularly, helping visualize these areas on PET. Malignancies with moderate to high 18F-FDG uptake include most lung cancers, colorectal cancers, esophageal cancers, gastric cancers, head and neck cancers, cervical cancers, ovarian cancers, breast cancers, lymphomas, and melanoma [4]. Hepatocellucar carcinoma, testicular cancers, renal cancers, sarcomas, and neuroendocrine tumors have variable 18F-FDG uptake [4]. Prostate adenocarcinoma, the most common cancer in males, has generally low metabolic activity, rendering 18F-FDG particularly less helpful for this malignancy in the primary setting, leading to potential false negative interpretation [5–7]. As 18F-FDG undergoes physiologic excretion through the bladder hinders evaluation of both bladder and prostate malignancies. Overall, 18F-FDG has been the most used oncologic tracer, but its applicability is not universal across all malignancies, nor is its uptake specific to only neoplasm. Though aberrant tumor growth in malignancy routinely results in increased 18F-FDG avidity, it is not tumor specific other benign tissue and benign conditions can also have variable uptake of 18F-FDG (e.g. inflammation or hyperplastic bone marrow) potentially leading to false positive findings [4,7]. As bone marrow hyperplasia and inflammation are not uncommon consequences after oncologic treatment including surgery, radiation therapy, and/or chemotherapy, 18F-FDG PET has limitations particulary in post-therapeutic assessment.

2.2. Other radiotracers

Beyond 18F-FDG, other markers exploit other cellular mechanisms for biologic imaging with PET. Other markers have been used to assess tumor proliferation with markers of DNA synthesis. As thymidine is unique to DNA, this has been exploited with various radiotracers including 11C-thymidine—which is limited by the short half-life of 11C—as well as thymidine analogs 18F-FLT and 8F-FMAU with the longer half-life of 18F [8]. 18F-FLT acts as a substrate of cytosolic thymidine kinase 1 (TK1), a key enzyme for salvage DNA synthesis, and 8F-FMAU is a substrate of thymidine kinase 2 (TK2), located in mitochondria, resulting in different distributions of these markers in tissue [9,10]. Although tumors tend to be less avid of 18F-FLT in comparison go 18F-FDG, tumor delineation from background tissue can be superior with 18F-FLT in regions such as the brain, mediastinum, and intestines, where normal physiologic uptake of 18F-FLT in these areas are much lower, yielding a high tumor-to-background ratio [1,11–13]. In a head-to-head comparison of 18F-FLT to 18F-FDG to assess chemotherapy response in patients with breast cancer who had imaging with both radiotracers, change in FLT uptake after one cycle of chemotherapy better predicted late changes in tumor marker levels and correlated well with eventual radiographic tumor response [14]. Though less employed in comparison to 18F-FLT, 18F-FMAU has shown ability to visualize breast, brain, lung, and prostate tumors. As 18F-FMAU shows low uptake in normal bone marrow—as opposed to 18F-FLT, which has high bone marrow uptake—18F-FMAU is more suitable for visualization of metastatic prostate cancer.

Radiolabeled Cu-ATSM (60/62/64Cu-ATSM) and 18F-FMISO are currently the two primary radiotracers employed for imaging tissue hypoxia—correlated with decreased sensitivity to treatment—and has been with worse clinical outcomes [15,16]. 60Cu-ATSM has been found to predict aresponse to therapy for NSCLC and predict both recurrence and survival outcomes for cervical and rectal cancers [17–19]. Clinically, pretreatment 18F-FMISO has been shown to predict survival in patients with head and neck cancer and glioblastoma multiforme [20,21].

Various amino acid radiotracers have been used, with 11C-MET (a methionine analog) the most common. It has found a niche in CNS malignancies. In malignant gliomas, decreased uptake during temozolomide therapy has shown improved time to progression; areas of uptake have shown areas at high risk of recurrence, and has helped distinguish post-radiation necrosis versus recurrent malignancy [22–24].

An additional class of radiotracers have aimed to assess hormone receptors, as receptors play an integral role in malignancies, paticulary prostate and breast cancers. 18F-FES is the most commonly used, showing correlation with estrogen receptor (ER) levels as well as response to aromatase inhibitors [25,26]. Ultimately, pretreatment uptake values have shown to predict patients who would or would not respond to therapy [25]. For prostate cancer, 18F-FDHT is an analog of 5α-dihydrotestosterone. Correlation with treatment response has not as well been shown in prostate cancer with this marker, though 18F-FDHT uptake has been associated with high PSA levels [27].

Single-phase / Dual-phase / Dynamic PET

Historically, PET imaging was obtained with a single static set of images obtained up to 1 hour after injection of 18F-FDG. As noted previously, a diagnostic limitation of PET imaging for oncologic diagnosis are the false positive findings secondary to inflammation quite commonly associated to therapeutic response. As 18F-FDG uptake and retention kinetics are potentially different between tumor and normal tissue inflammation, people have investigated more dynamic methods of acquiring metabolic PET data.

In a series of 21 patients with head and neck carcinomas, dual-time-point 18F-FDG PET studies helped differentiate malignancy from inflammation [28]. Standard uptake values (SUVs) of tumors were shown to increase on the second (delayed) study by mean of 12% in comparison to matched contralateral normal tissue which showed a mean decrease of 5% on delayed imaging (p<0.05) [28]. Inflammatory sites showed relatively stable uptake over the two scans; time interval between scans correlate with tumor SUV increase; and interval of greater than 30 minutes was recommended for separation [28].

For evaluation of pulmonary nodules, an early study of 36 patients siwht 38 pulmonary nodules, malignant or benign, underwent dual-time-point PET at 70 and 123 minutes post-injection [29]. A similar trend was seen with mean increase of tumor SUV of 20% (from 3.7 to 4.4) in malignant lesions from early to delayed scan (P<0.01); benign lesions showed stable and lower mean SUVs (1.1 on both early and delayed imaging) [29]. They determine a threshold of 10% increase from early to delayed imaging as the best predictor, reaching sensitivity of 100% and specificity of 89% [29]. Other data have shown similar trends of increased 18F-FDG uptake from first to second scan in malignant tissue and stable to decreased uptake in benign lesions [30].

In a study of 47 patients with suspected pancreatic cancer, patients had dual-time-point 18F-FDG PET imaging acquired 1 and 2 hours after injection; further, some patients had a third scan at the 3-hour time point after injection [31]. Twenty-two lesions were malignant, whereas 20 were benign. With a constant SUV threshold, the initial 1-hour PET was found to be 95% sensitive, missing one of 22 malignant lesions, and 83% accurate. With addition information of 2-hour PET imaging, retention characteristics of 18F-FDG increased diagnostic accuracy to 91.5%, with no decrease in false negatives [31]. The additional information provided by a 3-hour PET did not improve diagnostic accuracy beyond the dual-phase imaging obtained at the 1-hour and 2-hour time points [31].

With these potential diagnostic advantages from dual-phase PET-CT (with 2 PET scans separated by a time interval) has grown increasingly common. With the extra information provided with dual-phase imaging, people have further investigated ‘dynamic PET’ imaging, obtaining continuous PET data over time rather than at discrete or brief time spans, adding further breadth of data to kinetic profiles of uptake. Early work used dynamic continuous imaging to model discrete time-point imaging, showing linear change over time in patients with breast cancer. A recent study utilized dynamic PET imaging with 18F-FCho (18F-labelled fluoromethylcholine) to assess time-activity curves of space occupying brain lesions [32]. Another recent study used a dynamic PET-CT approach to assess cervical adenopathy in patients with oral/head and neck cancer; consecutive imaging at nine time points with PET/CT were obtained from 60-115 minutes after injection [33]. At our institution, we have recently initiated an adaptive radiation therapy protocol for patients with head/neck cancer in which patients receive weekly dynamic PET imaging over approximately 90 minutes during the course of treatment.

Though PET imaging acquires three-dimensional (3D) data, as CT technology has advanced to enable four-dimensional (4D) imaging with full 3D CT image sets corresponding to various portions of a respiratory cycle, so now have 4D-PET-CTs come into clinical use, with potential to reduce image smearing, improve accuracy of PET-CT co-registration, and increase the measured SUV [34,35]. A study evaluating 57 pulmonary lesions showed particular benefit in characterizing smaller tumors, with 4D studies showing higher differences in SUVmax percent difference in comparison to 3D studies (p<0.05) assessment of smaller lesion lung lesions, with better characterization [36]. A recent study illustrated utility of respiratory-correlated 4D-PET-CT for target delineation of squamous cell carcinoma of the esophagus, further indicating SUV threshold of 20% or 2.5 for autocontouring the gross tumor volume (GTV) [37]. Algorithms for semiautomatic contouring have also been proposed for pulmonary lesions with minimal difference (0.1 ± 0.1 mm) on phantom studies and 0.8 ± 0.2 mm on patient tumors [38]. Four-dimensional PET/CT has been reported to facilitate planning stereotactic radiotherapy of liver metastases [39] and pulmonary tumors [40].

3. PET parameters

From an oncologic standpoint, PET imaging is notably quite useful in its ability to quantitate parameters associated with PET uptake. An assortment of quantitative values can be obtained from each scan and from multiple-time-point scans, as well as across different scans obtained at different time points with respect to treatment (e.g. pre-treatment versus post-treatment), providing valuable information for treating physicians.

A common measurement of PET images for clinicians is the semi-quantitative value referred to as “standardized uptake value (SUV) [41].” Standardized uptake values are calculated throughout the three-dimensional array of CT regions, with variable SUVs throughout an image. SUV provides an index of regional tracer uptake and is a function of local radioactivity concentration, injected activity, and patient’s weight. 18F-FDG SUV can help differentiate tumor from tissue, and when used, corrections to calculation are recommended [42]. A common method of correction accounts for a patient’s lean body mass “SUVlbm,” commonly written as “SUVlbw” (lbw=“lean body weight”), “SUVlean,” or “SUL.”[43]


Within a region of interest (ROI) on a PET-CT, various PET quantitative factors can readily be obtained. The most commonly reported value from PET-CT oncologic imaging the maximum SUV value (SUVmax). SUVmax values are measured and reported at areas concerning for malignancy (e.g. a primary tumor and associated regional lymph nodes and distant metastases as well as other highly avid areas that may represent inflammation or reactive changes). Pre-treatment SUVmax with 18F-FDG has been reported to be prognostic for many organ sites including lung [44–46], head and neck [47], esophagus [48,49], gastroesophageal junction [49] gastric [50], pancreas [51] cervix [52], rectum [53,54], lymphoma [55], and soft tissue sarcoma [56].

Beyond SUVmax of an ROI, the arithmetic mean SUV (SUVmean) of voxels within the ROI have been used for oncologic assessment [57–59]. New parameters, which show promise in oncologic assessment, include the metabolic tumor volume (MTV) and total glycolytic activity (TGA) [60–63]. The MTV is defined as the tumor volume based on PET uptake and can be particularly helpful in comparison to CT-imaging when background density is similar to tumor density on CT. The boundary of MTV can be defined manually or with various parameters such as a fixed SUV threshold, percentage of SUVmax (e.g. 38%, 50%, and 60%), and gradient. On pre-treatment imaging prior to radiotherapy the volume delineated by PET-fusion to planning CT effectively corresponds to the MTV, which is utilized for biologically-targeted radiotherapy [64–66]. Such methods have been used extensively for lung radiotherapy planning, where PET staging is recommended [67]. MTV has shown to predict overall survival in lung cancer [61], head and neck cancer [60], and esophageal cancer [68].

Total glycolytic activity (TGA), defined as the (MTV) x (SUVmean), is the primary PET parameter that includes both both anatomic (size) as well as metabolic parameters (e.g. with 18F-FDG). In an analysis of TGA and MTV in 45 patients with oral or oropharyngeal SCC, stage, on univariate cox regression, MTV and TGA were the most associated with progression-free survival (PFS) and overall survival (OS) (p=0.002 and p=0.006, respectively), moreso than tumor grade (p=004) and SUVmax (p=0.56) [69].

Retention index (RI) is a dynamic parameter that can be calculated with dual-time-point (early and delayed) PET imaging, where RI is the difference of SUVmax on two scans divided by initial SUVmax. Rate of decline of RI during lung irradiation has shown to predict locoregional recurrence [70]. Further, in an analysis of 68 women with breast cancer, in comparison to other parameters including early and delayed SUVmax, RI showed best relation to biologic parameters including grade, Ki-67, and c-erbB-2 expression [71].


From an oncologic standpoint, beyond the importance of baseline PET imaging for staging and radiotherapy planning, subsequent PET scans, whether during treatment or subsequent, are used for assessment of treatment response. From such data, inter-PET analysis can be performed (e.g. comparison of a pre-treatment scan to a post-treatment scan), not to be confused with factors such as the RI which are measured across two different scans performed during two time points of a single PET (e.g. early and delayed scans). Inter-PET parameters include the difference or change in (delta, Δ) values of parameters already previously discussed as well as “percent of” (e.g. percent of baseline), percent reduction from baseline, and rate of change (velocity “VEL”). Examples of such variables comparing a new PET to a baseline PET are as indicated below, where t is the time between PETs..


4. Response criteria

Various methods for assessing and categorizing response of tumors based on radiographic imaging have been proposed, including the World Health Organization (WHO) criteria, the Response Evaluation Criteria in Solid Tumors (RECIST), and RECIST 1.1 [72–75]. Such criterica, depend on radiographic imaging, which may not best assess the biologic response, particularly given that metabolic response on PET routinely anatomic radiographic response on CT [76]. Accordingly, methods of categorizing response with PET have been developed, namely the European Organization for Research and Treatment of Cancer (EORTC) criteria and newer PET Response Criteria in Solid Tumors (PERCIST, version 1.0) [43,77]. A separate metric of response definitions using 18F-FDG PET has been developed for lymphoma response and used for clinical trials [78]. Definitions of criteria are delineated in Table 1, Table 2, Table 3, Table 4, and Table 5.

RECIST 1.1 (2009) [75]
EORTC (1990) [77]
PERCIST (2009) [43]
Measurable lesions have minimum size of 10 mm by CT scan,10 mm caliper measurement by clinical exam (lesions which cannot be accurately measured with calipers should be recorded as non-measurable), or 20 mm by chest X-ray. All other lesions are considered non-measurableTumor regions defined on pretreatment scan should be drawn on region of high 18F-FDG uptake representing viable tumor. Whole tumor uptake should also be recorded.

Uptake measurements should be made for mean and maximal tumor ROI counts per pixel per second calibrated as MBq/L.
Partial volume may affect measurement of 18F-FDG uptake.

Tumor size from anatomic imaging in relation to PET scanner resolution should be documented where possible.
Measurable target lesion is hottest single tumor lesion SUVlbw of ‘‘maximal 1.2-cm diameter volume ROI in tumor” (Peak SUVlbw). Peak SUVlbw is at least 1.5-fold greater than liver SUVlbw mean +2 SDs (in 3-cm spherical ROI in normal right lobe of liver). If liver is abnormal, primary tumor should have uptake > 2.0 SUVlbw mean of blood pool in 1-cm-diameter ROI in descending thoracic aorta extended over 2-cm z-axis.

Uptake measurements should be made for peak and maximal single-voxel tumor SUVlbw. Other SUV metrics, including SUVlbw mean at 50% or 70% of Peak SUV, can be collected as exploratory data; TLG can be collected ideally on basis of voxels more intense than 2 SDs above liver mean SUL

Table 1.

Evaluation of baseline lesions

[i] - RECIST, Response Evaluation Criteria in Solid Tumors, European Organization for Research and Treatment of Cancer; PERCIST, PET Response Criteria in Solid Tumors; CT, Computed Tomography, ROI: Region of interest, SD, standard deviation.

Target Lesions Non-Target Lesions
CR Disappearance of all target lesions. Any pathological lymph nodes must have reduction in short axis to <10 mm.Disappearance of all non-target lesions and normalization of tumor marker level. All lymph nodes must be non-pathological in size (<10 mm short axis).
PR ≥ 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.N/A
SD Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study.N/A
PD ≥ 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (including the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm.

The appearance of one or more new lesions is also considered progression.
Unequivocal progression of existing non-target lesions.

The appearance of one or more new lesions is considered progression.
Non-CR/ Non-PD N/APersistence of one or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits.

Table 2.

RECIST 1.1 (Non-metabolic) response criteria

[i] - Adapted from Eisenhauer et al. (2009) [75]. CR, Complete Response; PR, Partial Response; SD, Stable Disease; PD, Progressive Disease; N/A, Not Applicable

Response IWC[79] IWC+PET[80]
CR- no detectable clinical or radiographic evidence of disease
- no disease-related symptoms
- no biochemical abnormalities
- negative BMB (if positive before treatment)
- lymph nodes >1.5 cm at baseline regress to ≤ 1.5 cm
- lymph nodes 1.1-1.5 cm at baseline regress to ≤ 1.0 cm
-CR by IWC with a completely negative PET
- CRu, PR, or SD by IWC with a completely negative PET and negative BMB if positive prior to therapy
- PD by IWC with a completely negative PET and CT abnormalities (new lesion or increasing size of previous lesion) ≥ 1.5 cm (≥ 1.0 cm in the lungs) and negative BMB if positive prior to therapy
CRu- same as CR but either residual lymph mass > 1.5cm transverse diameter that has regressed > 75% or indeterminate BMB- CRu by IWC with a completely negative PET but with an indeterminate BMB
PR- ≥ 50% reduction in SPD of the six largest dominant nodes or nodal masses
- no increase in size of spleen, liver, or other nodes
- no new sites of disease
- CR, CRu, or PR by IWC with a positive PET at the site of a previously involved node/nodal mass
- CR, CRu, PR, or SD by IWC with a positive PET outside the site of a previously involved node/nodal mass
- SD by IWC with a positive PET at the site of a previously involved node/nodal mass that regressed to < 1.5 cm if previously > 1.5 cm, or < 1 cm if previously 1.1-1.5 cm
SD- less than PR but not PD- SD by IWC with a positive PET at the site of a previously involved node/nodal mass
PD- applies only to patients with PR or nonresponders
- ≥ 50% increase in the SPD from nadir of any previously identified abnormal node
- any new lesion
- PD by IWC with a positive PET finding corresponding to the CT abnormality (new lesion, increasing size of previous lesion)
- PD by IWC with a negative PET and a CT abnormality (new lesion, increasing size of previous lesion) of < 1.5 cm (< 1.0 cm in the lungs)
RD- applies only to patients with CR or Cru
- ≥ 50% increase in size of previously involved sites or
- ≥ 50% increase in greatest diameter of any previously identified node > 1cm in short axis or
- ≥ 50% increase in the SPD of ≥ 2 nodes or
- any new lesion
(not defined)

Table 3.

IWC+PET-based response definitions for lymphoma based on IWC designations and PET findings

[i] - Adapted from Juweid et al. (2005) [79]. IWC, International Workshop Criteria; PET, positron emission tomography; CR, complete remission; CRu, unconfirmed complete response, BMB, bone marrow biopsy, CT, computed tomography; PR, Partial Response; SPD, sum of the product of the diameters; SD, stable disease; PD, progressive disease; RD, relapsed disease

ResponseDefinitionNodal MassesSpleen, LiverBone Marrow
CRDisappearance of all evidence of disease(a) FDG-avid or PET positive prior to therapy; mass of any size permitted if PET negative

(b) Variably FDG-avid or PET negative; regression to normal size on CT
Not palpable, nodules disappearedInfiltrate cleared on repeat biopsy; if indeterminate by morphology, immunohistochemistry
PRRegression of measurable disease and no new sites≥ 50% decrease in SPD of up to 6 largest dominant masses; no increase in size of other nodes
(a) FDG-avid or PET positive prior to therapy; one or more PET positive at previously involved site
(b) Variably FDG-avid or PET negative; regression on CT
≥ 50% decrease in SPD of nodules (for single nodule in greatest transverse diameter); no increase in size of liver or spleenIrrelevant if positive prior to therapy; cell type should be specified
SDFailure to attain CR/PR, or PD(a) FDG-avid or PET positive prior to therapy; PET positive at prior sites of disease and no new sites on CT or PET
(b) Variably FDG-avid or PET negative; no change in size of previous lesions on CT
Relapsed Disease or PDAny new lesion or increase of previously involved sites by ≥ 50% from nadir.Appearance of a new lesion(s) > 1.5 cm in any axis, 50% increase in SPD of more than one node, or > 50% increase in longest diameter of a previously identified node >1 cm in short axis
Lesions PET positive if FDG-avid lymphoma or PET positive prior to therapy.
> 50% increase from nadir in the SPD of any previous lesionsNew or recurrent involvement

Table 4.

PET response definitions for clinical trials

[i] - From Cheson et al. Revised Response Criteria for Malignant Lymphoma (2007) [78]. CR, Complete Remission; FDG, 18F-fluorodeoxyglucose; PET, positron emission tomography; CT, computed tomography; PR = Partial Remission, SPD = sum of the product of the diameters; SD, stable disease; PD, progressive disease.

Metabolic CR
Complete resolution of 18F-FDG uptake within tumor volume so that it was indistinguishable from surrounding normal tissue.Complete resolution of 18F-FDG uptake within measurable target lesion so that it is less than mean liver activity and indistinguishable from surrounding background blood-pool levels.

No new 18F-FDG-avid lesions in pattern typical of cancer.

Disappearance of all other lesions to background blood-pool levels.
Percent reduction in SUVlbw should be recorded from measurable region and time (weeks) after treatment initiated
(i.e., CMR 290, 4).
If anatomic progression by RECIST, must verify with follow-up.
Metabolic PR
Reduction of minimum of 15% ± 25% in tumor 18F-FDG SUV after 1 cycle of chemotherapy, and >25% after >1 treatment cycle.

Reduction in extent of tumor 18F-FDG uptake is not a requirement for PR.
≥ 0.8 and ≥ 30% reduction of Peak* 18F-FDG SUVlbw in target measurable tumor.

No new lesions.
SUVlbw measurement is obtained from the most active lesion also present at baseline (even if a different lesion than measured at baseline).

No increase > 30% in SUVlbw or size of target or nontarget lesions.
Measurement is of the single most active lesion after treatment that was also present at baseline (e.g. may be a different lesion). Percent reduction in SUVlbw should be recorded and time in weeks after treatment initiated
(i.e., PMR -40, 3).
If anatomic progression by RECIST, must verify with follow-up.

Reduction in extent of tumor 18F-FDG uptake is not requiremed.
Metabolic SD
Increase in tumor 18F-FDG SUV <25% or decrease of < 15% and no visible increase in extent of 18F-FDG tumor uptake (20% in longest dimension).No CMR, PMR, or PMD.Peak SUVlbw in metabolic target lesion should be recorded, as well as time (weeks) from initation of most recent therapy, in weeks
(i.e., SMD -15, 7).
Metabolic PD
Increase in 18F-FDG tumor SUV of >25% within tumor region defined on baseline scan; visible increase in extent of 18F-FDG tumor uptake (20% in longest dimension) or appearance of new 18F-FDG uptake in metastatic lesions.(1) >30% and >0.8 increase in 18F-FDG Peak* SUVlbw from baseline in pattern typical of tumor and not of infection/treatment effect.


(2) Visible increase in extent of 18F-FDG tumor uptake (75% in TGA volume with no decline in SUVlbw


(3) New 18F-FDG-avid lesions that are typical of cancer and not related to treatment effect or infection.
PD other than new visceral lesions should be confirmed on follow-up study within 1 month unless clearly associated with PD by RECIST 1.1.
Should report percent change in Peak SUVlbw, time elased since treatment (weeks) and whether new lesions are present/absent and their number
(i.e., PMD, 135, 4, new: 5).

Table 5.

Metabolic Objective Response Assessment with 18F-FDG PET: EORTC & PERCIST 1.0

[i] - Adapted from Wahl et al.[43]. TLG, total lesion glycolysis; CMR, complete metabolic response; PMR, partial metabolic response; PD, progressive disease; SMD, stable metabolic disease; PMD, progressive metabolic disease; CR, complete remission; PR, partial remission.

[ii] - *Single-voxel SUVlbw (e.g. “SUVmax”) is commonly used but has been reported to be less reproducible than Peak SUVlbw, especially with very small single-voxel values. Peak SUVlbw represents the highest mean value of a 1.2-cm-diameter spherical volume within a lesion and reduces variability secondary to voxel-to-voxel noise. It is suggested, but not required, that lesions assessed on PERCIST be larger than the 1.5-cm-diameter volume ROI used to minimize partial-volume effects.

4. Clinical relevance of treatment response assessment

4.1. Head & neck cancer – Definitive/preoperative chemoradiation

18F-FDG PET has found a particularly significant role in treatment of head and neck cancers. It has long shown promise in its ability to prognosticate; in 37 patients from 1991-1994 with head and neck squamous cell carcinomas (HNSCC) receiving baseline 18F-FDG PET, SUVmax showed correlation with aggressive disease and potential prediction for survival [81].

Beyond prognostication, 18F-FDG PET is now routinely used to adapt treatment management, particularly in obviating surgical neck dissection in patients with complete response to initial radiation or chemoradiation therapy. Early studies have supported observation and omission of planned dissection after definitive radiotherapy for node-positive HNSCC with complete response on CT imaging, though at least selective nodal dissection was routinely practiced for residual neck masses [82,83]. With implementation of 18F-FDG PET, its negative predictive value has further supported omission of planned neck dissection, including in patients with residual neck mass/lymphadenopathy [84–88].

In an early study by Yao et al. [84], 41 patients from 2000-02 with locally-advanced HNSCC received radiation therapy with or without chemotherapy as upfront treatment had pretreatment and follow-up CT and 18F-FDG PET, with follow-up imaging 2.5-6 months (usually 3-4 months) post-treatment. Those without residual lymphadenopathy were observed. Twelve of 41 had residual lymphadenopathy; all had pathological testing, four with fine needle aspiration (FNA) biopsy, and eight had neck dissection. Follow-up 18F-FDG PET correlated better than follow-up CT for residual disease, and SUVmax cutoff of < 3.0 had 100% negative predictive value and 80% positive predictive value, serving as a good “rule-out” test for residual disease and potential to forego planned neck dissection in favor of initial observation, thus decreasing overall toxicity [84].

In a further analysis, Yao et al. (2005) [85] reviewed findings in 53 patients (70 heminecks; 17 patients with bilateral disease) with N2A or higher HNSCC with complete response to radiation therapy (± chemotherapy). Forty-two had clinically positive (exam or CT) lymphadenopathy but negative PET; this group had option to pursue dissection; 17 were observed, and 4 had negative neck dissection. The remaining 7 heminecks had clinically and PET-positive lymphadenopathy, six had neck dissection, one FNA; three were positive and four were negative for residual disease. No regional recurrences had occurred after median follow-up of 26 months (range 12-57 months). Negative predictive value of PET was 100% and positive predictive value 43%. They conclude that observation is safe if both CT and PET-negative 12 weeks after treatment and potentially also if CT reveals small (e.g. <2-3 cm) but PET-negative lymphadenopathy.

Porceddu et al. [88] analyzed a select cohort of 39 patients with HNSCC treated with definitive radiotherapy (± chemotherapy) with (a) complete regression of the primary HNSCC, (b) clinical evidence of residual neck mass by exam or CT imaging 8 weeks after treatment, (c) a follow-up 18F-FDG PET (median 12 weeks), and (d) either pathologic confirmation of neck status or > 12 months follow-up. Seven patients had residual PET uptake in the mass and proceeded to neck dissection (five were positive). Of the 32 with no residual tumor uptake, five had neck dissection (all pathologically negative), and 27 were observed (median follow-up of 34 months). One of the 27 observed patients had recurrence, yielding 97% negative predictive value. They conclude that in patients with a residual neck mass that is PET-negative 12 weeks after definitive radiotherapy (± chemotherapy), neck dissection is not required, and patients can be safely observed.

Such studies support timing of follow-up 18F-FDG PET to be 12 weeks post-treatment [84,85,88]. High negative predictive value (91%) has been shown at 16 weeks [86] post-treatment, though early time points (e.g. 4 weeks) have shown increased false positives [87]. Metaanalyses support PET ≥ 12 weeks after completion of definitive therapy for moderately higher diagnostic accuracy. An added benefit of 18F-FDG PET at this early follow-up interval is the potential to spare neck dissection in patients who show early distant metastatic disease [88,89].

Despite lack of any randomized prospective studies, significant retrospective evidence has continued to show similar findings. Recent metaanalyses [90–92], discuss 26, 27, and 51 studies including up to 2335 patients [92], overall supporting the high negative predictive value (approximately 95%) of follow-up PET and its value in omitting planned neck dissection. Further, despite the increased costs of PET imaging, PET-guided management in patients with complete response at the primary site has shown to be the more cost effective than CT-guided management or planned neck dissection [93].

4.2. Rectal cancer – Preoperative chemoradiation

Similar to HNSCC, first line treatment for locally-advanced rectal cancer includes upfront chemoradiation. In this setting, however, subsequent planned surgery remains standard of care. This multimodality neoadjuvant approach has shown to decrease local recurrence and improve overall survival [94,95]. Furthermore, neoadjuvant treatment has shown to increase sphincter-preserving surgery, conferring decreased surgical morbidity and improved quality of life [96–98].

Deferring subsequent surgical intervention in this disease site has similarly been investigated. In a cohort of 71 patients with distal rectal carcinoma considered resectable prior to concurrent chemoradiation with subsequent complete clinical response treated subsequently with observation alone (no planned surgery), five-year overall and disease-free survivals were 100% and 92%, respectively.

Improving restaging methods after neoadjuvant chemotherapy provides clinicians with increased information to guide management. Radiographic imaging modalities, however, are less sensitive to assessment of pathologic response, which is better characterized by metabolic imaging with 18F-FDG PET [54,99,100].

A number of studies have attempted correlation of 18F-FDG PET with tumor downstaging and response to neoadjuvant chemoradiation [100105]. In a study by Capirci et al. [100] including 81 patients with locally-advanced rectal cancer, percent reduction of SUVmax from baseline to follow-up 18F-FDG PET at 5-6 weeks after concurrent chemoradiation was most predictive of responders (71% reduction) versus non-responders (38% reduction) based on Mandard’s criteria. They propose a cutoff of 65% reduction, yielding 85% sensitivity, 80% specificity, 81% positive predictive value, 84% negative predictive value, and 81% accuracy.

Notably, surgery is routinely planned approximately 6 weeks after neoadjuvant treatment, as surgery at 6-weeks was shown to have more tumor downstaging than at 2 weeks [106]. However, further tumor response and increased survival has been noted with intervals > 7 weeks [107]. A recent similar study by Perez et al. (2012) [105] of 91 patients with follow-up 18F-FDG PET at 6 weeks but also again at 12 weeks showed best separation of good responders (49%) versus bad responders (51%) at 12 weeks (SUVmax of 9.1 in bad responders vs. 4.3 in good responders, p<0.001) rather than at 6 weeks (SUVmax of 6.4 in bad responders versus 5.8 in good responders, p=0.5). Good responders were more likely to have complete clinical response (38% vs. 7%, p=0.001) complete or near-complete pathologic response (45% vs. 16%, p=0.008) and smaller pathologic size (3.3 vs. 4.4, p=0.03). Increase from early-phase (1 hour after injection) to delayed-phase PET (3 hours after injection) at the 6 –week time point was 67% accurate of predicting good vs. bad responders. A good responder was considered anyone with SUV12week < SUV6week. They conclude that approximately half of patients will have continued improved response beyond 6 weeks, whereas approximately half will have increased metabolic activity. Dual-phase imaging at the 6-week point may help stratify the two groups, which may help guide clinicians in best timing for planned surgery.

In rectal cancer, 18F-FDG PET restaging does show promise in potentially affecting treatment management; prospective studies investigating its role in this setting are awaited.

4.3. Lymphoma

18FDG-PET finds various roles in management of lymphoma. For staging in Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL), PET with CT (PET-CT) has been shown to improve sensitivity and specificity in evaluation of nodal and extranodal sites in comparison to contrast-enhanced CT without PET [108,109]. It has further shown to be 92% sensitive for bone marrow involvement in HL [110]. Beyond staging, PET has been used for post-chemotherapy restaging, assessing response during chemotherapy at initial diagnosis, and also during salvage treatment. In current NCCN guidelines for both HL & NHL, PET-CT has variably been incorporated into staging, restaging during chemotherapy, and restaging after chemotherapy; routine PET-CT in the surveillance setting, however, is recommended against secondary to false-positive risk [111,112].


The role for PET in lymphoma is clearest in the setting of restaging, either during or subsequent to treatment. PET has a very high negative predictive value (88-100%, see Table 6) [113]. Further, after treatment, PET is superior to CT for distinguishing residual mass with versus without residual viable disease (e.g. post-treatment fibrosis) [114]. Spaepen et al. report on two cohorts, one with HL [115] and one with NHL [116] who were assessed with PET at baseline and after completion of chemotherapy. In the HL cohort [115] of 60 patients, 55 were PET- (PET negative) after chemotherapy and 5 were PET+ (PET positive). All 5 PET+ patients had relapse of disease. Of the PET- patients, 91% remained without recurrence after median follow-up of 32 months. Two-year PFS rates were 91% vs. 0% for PET- vs. PET+ patients (p<0.0001). Similarly, in the NHL cohort [116] of 93 patients, all 27 PET+ patients after chemotherapy had relapse (median 2.4 months), whereas 84% of the PET- patients remained in remission (median 21 months). Two-year PFS rates were 85% vs. 4% for PET- vs. PET+ patients (p<0.0001). Halasz et al. (2011) [117] report a summary of post-chemotherapy and interim PET results. They further report a cohort of 59 patients with NHL, receiving 36 Gy (median) consolidative in-field radiation therapy (RT) (all patients) and R-CHOP chemotherapy (58 of 59 patients). Median follow-up was 47 months. In the 66% with negative PET after chemotherapy, 3-year PFS was 97%. However, with this treatment including RT, 3-year PFS was 90% in those with positive PET after chemotherapy (p-value not reported).

Author Year n PPV (%) NPV (%)
Spaepen [115]20016010091%
Cerci [118]201013092%100%
Engert [119]2012728N/A95%
Bangerter [120]19988990%98%
Jerusalem [114]19993543%100%
Zinzani [121]19993193%100%
Mikhaeel [122]20004560%100%
Naumann [123]20011586%88%
Spaepen [116]20019370%100%
Gigli [124]20084275%94%
Cashen [125]20115080%92%

Table 6.

Positive and negative predictive value of PET-CT in lymphoma staging

[i] - Adapted from Cheson [113]. HL, Hodgkin Lymphoma; NHL, Non-Hodgkin Lymphoma; PPV, positive predictive value; NPV, negative predictive value

Interim (during-chemotherapy) PET

More research has investigated interim (during chemotherapy) 18FDG-PET for assessment of treatment response and prognostication (see Table 7). Cerci et al. [126] assessed interim PET after 2 cycles of ABVD (coxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapy in 104 patients with early and advanced Hodgkin lymphoma. Negativity vs. positivity at interim PET significantly predicted event-free survival (EFS), 91% vs. 53% at 3 years for PET- vs. PET+ patients (p<0.001). On univariate analysis, interim PET was the best prognosticator of event-free survival (p<0.001), more so than stage, bulky disease, and international prognostic score (IPS) (p=0.24, p=0.15, p=0.99, respectively). It however failed to prognosticate survival (p=0.2), which was better predicted by age (cutoff 45 years, p=0.01) and IPS (0-2 vs. 3-7, p=0.04).

Author Year n FU
# cycles Interim PET Response Outcomes p-value
Hutchings [127]200585402-374% PET-
11% PET+
15% MRU
97% 2y PFS
46% 2y PFS
Hutchings [109]20067723279% PET-
21% PET+
96% 2y PFS
0% 2y PFS
Kostakoglu [128]20062321174% PET-
26% PET+
100% 2y PFS
13% 2y PFS
Zinzani [129]20064018280% PET-
20% PET+
97% PFS
12% PFS
Gallamini [130]200726026281% PET-
19% PET+
95% 2y PFS
13% 2y PFS
Markova [131]20095025472% PET-
28% PET+
100% PFS
28% PFS
Cerci [126]201010436271% PET-
29% PET+
91% 3y EFS
53% 3y EFS
Jerusalem [114]20002818382% PET-
18% PET+
62% 2y PFS
0% 2y PFS
Spaepen [132]200270362-353% PET -
47% PET +
16% progressed
100% progressed
Haioun [133]20059024260% PET -
40% PET +
82% 2y EFS
43% 2y EFS
Mikhaell [134]2005121292-341% PET -
43% PET +
16% MRU
88% 5y PFS
16% 5y PFS
59% 5y PFS
Ng [135]200745311-569% PET -
31% PET +
15% relapsed
61% relapsed
Han [136]200940242-468% PET -
32% PET +
10% progressed
71% progressed
Pregno [137]200988262-472% PET -
28% PET +
85% 2y PFS
72% 2y PFS
Safar [138]200911238263% PET -
37% PET +
84% 3y PFS
47% 3y PFS
Cashen [125]201150152-352% PET -
48% PET +
85% 2y PFS
63% 2y EFS
Zinzani [139]20119150variable62% PET-
39% PET+
75% 4y EFS
18% 4y EFS

Table 7.

Prognostication of interim PET in lymphoma

[i] - HL, Hodgkin Lymphoma; NHL, Non-Hodgkin Lymphoma; PET, positron emission tomography; FU, Follow-up; n, number of patients in study with interim PET scan; EFS, event-free survival; PFS, progression-free survival; MRU, minimal residual uptake; # cycles, number of cycles of chemotherapy completed prior to interim PET; NR, not reported

Drug salvage

In the setting of relapsing/refractory Hodgkin lymphoma, interim PET after 2 cycles of salvage high-dose chemotherapy has been assessed. Limited retrospective data from Castagna et al. [125] has shown similar prognostic potential, reporting 2-year progression-free survival of 93% (PET-negative) versus 10% (PET-positive, p<0.001).

PET Response-Adapted radiotherapy

In the German Hodgkin Study Group HD15 trial (2012) [119,140] with over 2,000 patients with advanced-stage Hodgkin lymphoma, 3 BEACOPP chemotherapy regimens were compared in a non-inferiority randomized trial. Radiotherapy was implemented with a “PET-guided” adaptive approach based on post-chemotherapy response regardless of treatment arm. If a PET-positive persistent mass 2.5cm or larger was present after completion of chemotherapy (median 21 days), 30Gy local radiation therapy was administered for consolidation. Negative predictive value for post-chemotherapy PET was 94% at 12 months follow-up. In the 3 arms, five-year freedom from failure ranged from 84%-89%, and five-year survival ranged from 92-95%. Consolidative radiotherapy was not randomized and was administered to 11% of patients (compared to 71% in HD9 [141]). With such excellent outcomes with this PET-guided radiotherapy approach, the authors indicate this approach as their current standard of care. Longer follow-up and prospective clinical trials assessing need for consolidative radiotherapy are still awaited.


Figure 1.

This is a 12-year-old female with a history of Stage IIB bulky nodular sclerosing Hodgkin lymphoma involving the bilateral cervical chain and mediastinum. She had achieved a complete response with 6 cycles of COPP-ABV chemotherapy. She then received a total radiation dose of 3060 cGy in 17 fractions of 180 cGy to the cervical and mediastinal lymph nodes. As seen in the serial PET/CT images (b-f above), the mediastinal and cervical lymph nodes responded well. However, by 28 months post-treatment, a left iliacus muscle lymph node became suspicious for lymphoma involvement (g – max SUV 5.0). By 31 months post-treatment, this node had increased further (h – max SUV 7.7).

4.4. Esophageal cancer – Definitive/preoperative

The role of multimodality therapy for esophageal and gastroesophageal cancer has historically not been well defined. Resection has been considered standard treatment for patients with resectable/localized disease without strong evidence supporting neoadjuvant therapy, despite significant risk for local and distant recurrences yielding poor 5-year survival rates ranging from 15-39%[142]. Neoadjuvant treatment is increasingly becoming adopted as standard of care for locally-advanced disease, with use continuing to increase [143,144]. Multiple prospective trials did not report survival benefit with neoadjuvant chemoradiotherapy [145–147], and randomized studies supporting neoadjuvant treatment are scarce. Walsh et al. (1996) [148] showed increased 3-year overall survival from 6% to 32% with neoadjuvant treatment (p<0.01) in a study of 113 patients. In the recently published CROSS trial [149] with 366 patients, addition of neoadjuvant chemoradiation increased R0 resection (resection with negative pathologic margins) from 69% to 92% (p<0.001) and more than doubled median overall survival from 24 to 49 months (hazard ratio = 0.66, p=0.003).

In patients receiving neoadjuvant chemoradiation, a portion—29% in the Dutch CROSS study—are found to have pathologic complete response on subsequent surgery. In a single-institution review, pathologic complete response from neoadjuvant treatment was associated with higher 5-year and overall survival (48% vs. 18% and 50 months vs. 28 months, respectively) in comparison to patients without complete response [150]. With treatment response bearing significant prognostic potential, assessment of response to neoadjuvant treatment for esophageal cancer has been an area of increasing research [150–163].

In an early study by Weber et al. (2001) [151] in forty patients receiving neoadjuvant chemotherapy (without radiotherapy) for esophageal cancer, patients had 18FDG-PET both pretreatment and after 14 days of treatment (during chemotherapy). Metabolic response was considered decrease of 35% from baseline, which was associated with 93% sensitivity and 95% specificity for prediction of clinical response. Responders had longer time to progression/recurrence and overall survival.

In a follow-up study [152], patients had three 18FDG-PET scans: one pretreatment, one during treatment (2 weeks after starting), then 3-4 weeks preoperatively (but after neoadjuvant treatment. Responders had more decrease at 2 weeks (44% vs. 21%, p<0.01) and preoperatively (70% vs. 51%, p=0.01). During-treatment PET had higher power than the preoperative PET treatment to predict response (area under curve (AUC) of receiver operator characteristic (ROC) 0.78 vs. 0.88), though difference was not statistically significant (p=0.40). Best cutoff for response in this cohort was 30% reduction from baseline (93% sensitive, 88% accurate), who all proceed to have R0 resection. Responders by this PET criteria had higher survival (median 38 vs. 18 months; 2-year rates 79% vs. 38%, p<0.01).

Analysis of gastroesophageal junction tumors again showed improved prognostic potential with PET using percent reduction of SUVmax 2 weeks after treatment start (p=0.03) versus after completion of neoadjuvant treatment (p=0.09) [153]. Though percent reduction is routinely used to assess response, thresholds of decrease of SUVmax (e.g. decrease of ≥10) from before to after neoadjuvant treatment have shown to predict significant histopathologic response [158].

More recent studies have showed other metrics as better predictors of response. In a comparison of SUVmax, MTV based on fixed threshold of 2.5 SUV, and SUVmean (of MTV), and TGA, MTV and TGA were both 91% sensitive in predicting histopathologic response when also using CT, but MTV increase specificity from 90% to 93%. Most predictive was TGA (AUC=0.95) followed by MTV (AUC=0.92), SUVmax (AUC=0.84), and SUVmean (AUC=0.82) [159]. Further, metabolic response criteria (e.g. PERCIST) have shown better assessed response in comparison to non-metabolic methods (e.g. RECIST and WHO) [159,163].

With various studies showing prognostic potential of 18FDG-PET early during treatment, there is question as to the utility of PET to potentially facilitate treatment modification [152]. Kwee (2010) [160] performed a metaanalysis of 20 PET-response studies including 849 patients; it however showed wide ranges of sensitivity and specificity with overall AUC of 0.78. Based on the pooled data, PET was not recommended for routine clinical use to guide neoadjuvant treatment. Furthermore, in a retrospective single-institution review [164], patients treated with neoadjuvant chemotherapy followed by surgery had similar freedom from local failure (p=0.92) and overall survival (p=0.15) in comparison to patients receiving definitive chemoradiation who attained metabolic CR (SUV<3). Furthermore, in this retrospective study, though not statistically significant, rate of death in the definitive chemoradiation group was higher than in the surgical group despite worse baseline characteristics.

Similar to head and neck cancer, prospective studies are awaited to formally assess necessity of surgical management after complete metabolic response to neoadjuvant chemoradiation therapy in operable/resectable patients.

4.5. Non-Small Cell Lung Cancer (NSCLC)

18FDG-PET is currently recommended by NCCN guidelines for routine staging of stage I-III NSCLC [67]. Radiotherapy planning with PET fusion has further been recommended for biologically-targeted radiotherapy in which 3D-PET fusion is implemented for tumor delineation, with PET performed with minimal delay between PET and start of treatment, given propensity for rapid disease progression [64–66,165]. Metabolic (PET) response to treatment has been shown to pre-date radiographic (CT) response. Despite increasing data showing utility of PET for assessing treatment response in NSCLC and predicting outcomes including survival, guidelines currently do not recommend PET in this setting [44,45,67,76,166–177].

In an early study of 15 patients receiving chemotherapy for IIIB-IV NSCLC, patients received weekly PET starting at initiation of chemotherapy until completion of 2 cycles (6 weeks later) [171]. Reduction of SUVmax by 50% week 1 to week 3 was predictive of survival of > 6 months, thus facilitating prediction of response to treatment. Those with less reduction died within 6 months. In patients without early response, management may thus be altered to forego futile chemotherapy. In an early study [167] of 15 stage I-III patients receiving radiotherapy, patients received 3 PETs: one pre-treatment, one during treatment after approximately 45 Gy, and one 3 months post-treatment. Response during treatment was shown to correlate with overall response after treatment (p=0.03), and SUV during treatment correlated with SUV 3 months after (p<0.001). A number of studies with prospective PET data with cutoffs are listed in Table 8.

Author Year n Stage Criteria Outcome p
Vansteenkiste [172]198515IIIA50% decreaseOS0.03
MacManus [173]200373I-IIICMROS<0.01
Weber [174]200357IIIB-IV20% decreaseOS<0.01
Hellwig [175]200447IIB-IIISUV < 4OS<0.01
Eschmann [176]200770IIICMR or 80% decreaseOS<0.01
de Geus-Oei [177]200751IB-IV35% decreaseOS0.02
Nahmias [171]200716IIIB-IV50% decrease from week 1 to week 3OS<0.01
Tanvetyanon [178]200889IB-IIIBCMROSNS
At 12 months
Mangona [45]2012129IA-IBSUV ≥ 3.9
60% decrease
SUV ≥ 6.0
During treatment
Mangona [70]201216IIB-IIIB30% decrease
decrease ≥ 4

Table 8.

PET Cutoffs/Criteria and Outcomes in NSCLC

[i] - Adapted from Hicks et al. [170]. CMR, complete metabolic response; OS, overall survival; LF, local failure; CSS, cause-specific survival; LRR, locoregional recurrence; NS, not statistically significant.*100% sensitive. 100% specific.


Stereotactic body radiotherapy (SBRT), employing modern techniques including 4-D treatment planning and image-guided radiotherapy (IGRT) has been shown to be an effective, cost-efficient, treatment option for definitive management of early-stage NSCLC as well as lung metastases from other organs with excellent tumor control rates; in comparison to medically-operable patients who are treated with resection, retrospective data of primarily medically-inoperable patients with poor pulmonary function suggests excellent tumor control with SBRT with rates similar to that of sublobar resection and minimal toxicity [179–191].

In a large single-institution analysis [45] of 129 consecutive NSCLC tumors treated with SBRT, 58% enrolled on a prospective phase II protocol, patients had baseline and serial follow-up PET imaging. Sixteen patients additionally had weekly on-treatment 4D-PET-CT. Median follow-up was 19 months and median time until local failure (LF) of 15 months. A total of 475 PETs were obtained. Change in SUV from pre-treatment to follow-up are seen in Figure 1 and stratified by status of LF vs. no-LF based on last follow-up. Though baseline SUVmax was higher in the LF group (12.4 vs. 6.5, p=0.0001), difference was not significant at 1.5 and 6 months, as both groups responded. SUV at 12 months, however, was significantly higher for the LF vs. no-LF group (6.8 vs. 2.5, p=0.02). Cutoffs predictive of LF were 12-month SUV ≥ 3.9 (100 sensitive), 12-month SUV ≥ 6 (100 specific), and 12-month SUV ≥ 40% of baseline (see Table 8). Analysis of SUVmax velocity showed trend for higher velocity at 12 months (+0.18 SUV/month vs. -0.03 SUV/month, p=0.058). On multivariate logistic regression, 12-month SUV was most predictive of LF (p=0.057).


Assessment of response for NSCLC with serial 18FDG-PET. 129 node-negative non-small-cell lung tumors were treated with stereotactic body radiation therapy (SBRT) and followed with routine follow-up imaging. SUV for tumors with eventual local failure (LF) and no local failure (no-LF) at last follow-up are compared. (a) Plot of SUVmax vs. time, with baseline PET SUVmax at t=0. Tumors with resulting LF show higher SUVmax both at pre-treatment and at 12-months follow-up, though SUVmax at 1.5 and 6 months were similar. (b) Plot of normalized SUVmax (baseline normalized SUV = 1). Normalized SUVmax is higher at 12 months in the LF group but similar at other time points. Values are plotted as box plots with thick black line representing the median value, lower box border the 25th percentile, upper box border the 75th percentile, and outliers with points. PET SUVs subsequent to any treatment for recurrence (e.g. chemotherapy) were excluded; thus, the no-LF group had data at longer follow-up (e.g. 24, 36, and 48 months).

Figure 2.

SUV kinetics after stereotactic body radiotherapy for NSCLC

Hyperfractionated radiotherapy

In a cohort of 16 patients with locally-advanced NSCLC enrolled on a phase II protocol, patients had PET at baseline, weekly during treatment, and at follow-up [70,192] (see Figure 2). Patients received hyperfractionated radiation therapy 1.5 Gy BID with concurrent chemotherapy either as definitive treatment (n=12) or as neoadjuvant treatment (n=4) delivering RT with daily online cone-beam CT for image guidance and intensity modulated radiotherapy (IMRT) to minimize potential normal tissue toxicity [190,193,194]. After potential follow-up of 20 months (range 12-28), 7 had locoregional recurrence (LRR), and 8 died (5 of disease). Interestingly, there was trend for higher SUVmax at baseline in those without LRR (the no-LRR group) than in those with LRR (19.0 vs. 11.9, p=0.08), an inverse relationship than expected. The rate of SUV decrease in the LRR group during RT was 1.6 per week, significantly faster than the no-LRR group (0.23 per week, p=0.02) such that SUV values were similar for both groups by the 4th on-treatment PET (p=0.95) (see Table 9). A during-RT decrease of less than 4 from baseline was predictive of LRR (p<0.01), and a during-RT decrease less 30% from baseline was predictive of death from disease (p<0.01). Velocity of retention index from PET1 to PET-FU predicted overall survival (+1.6%/week in those who died vs. -1.7%/week in those alive, p=0.03).

PET0 PET1 PET2 PET3 PET4 PET-FU Velocity during RT
SUVmax LRR11.99.511.410.69.86.7-0.23/week
p 0.08 0.02 0.13 0.32 0.95 0.66 0.02
SUVdelayed-SUVearly LRR1.902.002.151.300.95-0.05/week
p 0.02 0.15 0.82 0.55 0.82 0.15
Retention IndexLRR23.3%22.5%22.8%14.3%18.4%-0.8%/week
p 0.92 0.88 0.16 0.57 0.76 0.04

Table 9.

On-treatment SUV kinetics of locally-advanced NSCLC treated with concurrent chemoradiation

[i] - Patients had PET-CT before treatment for staging/planning (PET0), weekly during treatment (PET1, PET2, PET3, and PET4), and at 6-12 weeks follow-up (PET-FU); RT, Radiation Therapy; LRR, locoregional recurrence; no-LRR, no locoregional recurrence at last follow-up.


1.5 Gy twice daily with concurrent Taxotere. He had a complete metabolic response to treatment evident at first follow-up PET 1-month after treatment. SUV values (early → delayed): (a) Pre: 29.4 → 36.9; (b) Week 1: 17.8 → 23.6; (c) Week 2: 13.3 → 16.0; (d) Week 3: 15.7 → 17.0; (e) Week 4: 4.6 → 5.8; (f) Week 5: 4.2 → 5.3; (g) 1 month follow-up: 2.0 → 2.2

Figure 3.

This is a 68-year-old male who presented with dyspnea and hemoptysis. Workup revealed a stage IIIB (T4, N2, M0) squamous cell carcinoma of the right lower lobe, 7cm in size invading the mediastinum. He received hyperfractionated intensity-modulated radiotherapy, 66 Gy in 1.5 Gy fractions twice daily.


SUV values (early → delayed): (a) Pre: 23.4 → 28.7; (b) Week 1: 14.8 → 16.0; (c) Week 2: 11.0 → 12.7; (d) Week 3: 11.0 → 12.8; (e) Week 4: 12.1 → 15.; (f) 6-week FU: 6.5 → 8.; (g) 6-month FU: 12.5 → 15.7; (h) 8-month FU: 4.9 → 6.3

Figure 4.

This is a 66-year-old male who presented with right shoulder pain. Workup revealed a clinical stage IIIA (T3 N1 M0) squamous cell carcinoma of the right upper lobe of the lobe with chest wall invasion causing destruction of ribs 2-4. He received hyperfractionated intensity-modulated radiotherapy 72Gy, 1.5 Gy twice daily, with concurrent and maintenance taxotere for 4 months. SUV nadir occurred at 6 weeks with evident local progression at 6 months.

PET shows prognostic potential in this disease site from prior to treatment to early in treatment, to later in follow-up. It further holds potential for adjusting management (e.g. discontinuing ineffective chemotherapy, potentially modifying radiation therapy during treatment, and predicting delayed local failure for potential earlier biopsy/intervention). We await further prospective PET data and clinical trials to best define the role of PET in assessment of treatment in NSCLC.

5. Future directions

As PET is used for staging and radiotherapy prior to treatment for a number of organ sites, PET further has potential for restaging and replanning radiotherapy during the course of therapy. Beyond mid-treatment prognostication, this facilitates potential treatment modification. For radiotherapy re-planning, potential changes are include modification of target volumes based on anatomic changes from treatment, modification of boost volumes, and potentially adjustment of prescription dose based on response (e.g. higher dose for poor responders vs. less dose for good responders). Such investigations are currently ongoing in clinical protocols.

In treatment of locally-advanced head and neck squamous cell carcinomas, our institution has initiated a prospective, non-randomized trial evaluating the utility of such an adaptive approach focusing on target volume adaptation. Patients receiving 70 Gy IMRT in 35 daily fractions (7 week duration) with concurrent cisplatin or cetuximab are eligible. 18FDG-PET-CT is utilized for treatment planning. Repeat PET-CTs and diagnostic CTs are obtained after fractions 10 and 22 for the purpose of treatment adaptation. Three different treatment plans will be created, one for fractions 1-12 (based on pre-treatment PET-CT), one for fractions 13-24 (based on PET-CT after fraction 10), and one for fractions 25-35 (based on PET-CT after fraction 22). Such an adaptive approach may help decrease dose delivered to normal tissue as tumors decrease in size during treatment, potentially decreasing toxicity. On this protocol, patients also obtain weekly PET-CTs for assessment of treatment response, though prescription dose is not modified in this study.

For non-small cell lung cancer, investigators have further used on-treatment PET to facilitate PET-adaptive replanning, with PET-adaptive dose escalation incorporated into a currently-enrolling Radition Therapy Oncology Group (RTOG) Protocol, RTOG 1106 [195,196]. All patients on this protocol will have 18FDG-PET; however, a subset are planned to also have 18F-MISO-PET at staging.

As such radiotracers beyond 18F-FDG show particular promise, further results of clinical trials implementing these are awaited.

6. Conclusion

Over the past 20 years, the body of data assessing treatment response with PET has grown significant. Assessing treatment response with PET can yield highly prognostic information. Such information, however, may have no end-effect on management. As clinicians, many of our PET-based decisions are based on retrospective and prospective data without comparison of management options based on PET results. Such results are significantly hypothesis-generating. The high negative predictive value of PET in various organ sites may increase comfort of clinicians when considering omitting potentially unnecessary interventions (e.g. neck dissection after complete metabolic response of locally-advanced head and neck cancer to chemoradiation, esophagectomy after complete metabolic response to chemoradiotion, or consolidative radiotherapy after complete metabolic response in Hodgkin lymphoma). High-level evidence to justify such treatment-adapting decisions based on PET are currently lacking, thus we caution application of such data as justification for modifying standard of care. We strongly encourage PET-adaptive management under the guise of clinical trials at this time, as the role of PET in oncology continues to best be defined.


Special thanks to Dr. Katie Traylor, Rob Ceruti, and Matthew Johnson of Nuclear Medicine for their assistance with PET figures presented in this chapter.


1 - Dunphy MPS, Lewis JS. Radiopharmaceuticals in preclinical and clinical development for monitoring of therapy with PET. J. Nucl. Med. 2009 May;50 Suppl 1:106S–21S.
2 - Conti PS, Lilien DL, Hawley K, Keppler J, Grafton ST, Bading JR. PET and [18F]-FDG in oncology: a clinical update. Nucl. Med. Biol. 1996 Aug;23(6):717–35.
3 - Bos R, van Der Hoeven JJM, van Der Wall E, van Der Groep P, van Diest PJ, Comans EFI, et al. Biologic correlates of (18)fluorodeoxyglucose uptake in human breast cancer measured by positron emission tomography. J. Clin. Oncol. 2002 Jan 15;20(2):379–87.
4 - Juweid ME, Cheson BD. Positron-emission tomography and assessment of cancer therapy. N. Engl. J. Med. 2006 Feb 2;354(5):496–507.
5 - Siegel R, Naishadham D, Jemal A. Cancer statistics, 2012. CA Cancer J Clin. 2012 Feb;62(1):10–29.
6 - Lee ST, Lawrentschuk N, Scott AM. PET in prostate and bladder tumors. Semin Nucl Med. 2012 Jul;42(4):231–46.
7 - Long NM, Smith CS. Causes and imaging features of false positives and false negatives on F-PET/CT in oncologic imaging. Insights Imaging. 2011 Dec;2(6):679–98.
8 - Bading JR, Shields AF. Imaging of cell proliferation: status and prospects. J. Nucl. Med. 2008 Jun;49 Suppl 2:64S–80S.
9 - Juweid ME, Stroobants S, Hoekstra OS, Mottaghy FM, Dietlein M, Guermazi A, et al. Use of positron emission tomography for response assessment of lymphoma: consensus of the Imaging Subcommittee of International Harmonization Project in Lymphoma. J. Clin. Oncol. 2007 Feb 10;25(5):571–8.
10 - Tehrani OS, Douglas KA, Lawhorn-Crews JM, Shields AF. Tracking cellular stress with labeled FMAU reflects changes in mitochondrial TK2. Eur. J. Nucl. Med. Mol. Imaging. 2008 Aug;35(8):1480–8.
11 - Kasper B, Egerer G, Gronkowski M, Haufe S, Lehnert T, Eisenhut M, et al. Functional diagnosis of residual lymphomas after radiochemotherapy with positron emission tomography comparing FDG- and FLT-PET. Leuk. Lymphoma. 2007 Apr;48(4):746–53.
12 - Smyczek-Gargya B, Fersis N, Dittmann H, Vogel U, Reischl G, Machulla H-J, et al. PET with [18F]fluorothymidine for imaging of primary breast cancer: a pilot study. Eur. J. Nucl. Med. Mol. Imaging. 2004 May;31(5):720–4.
13 - Dittmann H, Dohmen BM, Paulsen F, Eichhorn K, Eschmann SM, Horger M, et al. [18F]FLT PET for diagnosis and staging of thoracic tumours. Eur. J. Nucl. Med. Mol. Imaging. 2003 Oct;30(10):1407–12.
14 - Pio BS, Park CK, Pietras R, Hsueh W-A, Satyamurthy N, Pegram MD, et al. Usefulness of 3’-[F-18]fluoro-3’-deoxythymidine with positron emission tomography in predicting breast cancer response to therapy. Mol Imaging Biol. 2006 Feb;8(1):36–42.
15 - Graeber TG, Osmanian C, Jacks T, Housman DE, Koch CJ, Lowe SW, et al. Hypoxia-mediated selection of cells with diminished apoptotic potential in solid tumours. Nature. 1996 Jan 4;379(6560):88–91.
16 - Hockel M, Schlenger K, Aral B, Mitze M, Schaffer U, Vaupel P. Association between tumor hypoxia and malignant progression in advanced cancer of the uterine cervix. Cancer Res. 1996 Oct 1;56(19):4509–15.
17 - Dehdashti F, Grigsby PW, Mintun MA, Lewis JS, Siegel BA, Welch MJ. Assessing tumor hypoxia in cervical cancer by positron emission tomography with 60Cu-ATSM: relationship to therapeutic response-a preliminary report. Int. J. Radiat. Oncol. Biol. Phys. 2003 Apr 1;55(5):1233–8.
18 - Dietz DW, Dehdashti F, Grigsby PW, Malyapa RS, Myerson RJ, Picus J, et al. Tumor hypoxia detected by positron emission tomography with 60Cu-ATSM as a predictor of response and survival in patients undergoing Neoadjuvant chemoradiotherapy for rectal carcinoma: a pilot study. Dis. Colon Rectum. 2008 Nov;51(11):1641–8.
19 - Dehdashti F, Mintun MA, Lewis JS, Bradley J, Govindan R, Laforest R, et al. In vivo assessment of tumor hypoxia in lung cancer with 60Cu-ATSM. Eur. J. Nucl. Med. Mol. Imaging. 2003 Jun;30(6):844–50.
20 - Rajendran JG, Schwartz DL, O’Sullivan J, Peterson LM, Ng P, Scharnhorst J, et al. Tumor hypoxia imaging with [F-18] fluoromisonidazole positron emission tomography in head and neck cancer. Clinical Cancer Research. 2006;12(18):5435–41.
21 - Spence AM, Muzi M, Swanson KR, O’Sullivan F, Rockhill JK, Rajendran JG, et al. Regional hypoxia in glioblastoma multiforme quantified with [18F] fluoromisonidazole positron emission tomography before radiotherapy: correlation with time to progression and survival. Clinical Cancer Research. 2008;14(9):2623–30.
22 - Galldiks N, Kracht LW, Burghaus L, Thomas A, Jacobs AH, Heiss W-D, et al. Use of 11C-methionine PET to monitor the effects of temozolomide chemotherapy in malignant gliomas. Eur. J. Nucl. Med. Mol. Imaging. 2006 May;33(5):516–24.
23 - Lee IH, Piert M, Gomez-Hassan D, Junck L, Rogers L, Hayman J, et al. Association of 11C-methionine PET uptake with site of failure after concurrent temozolomide and radiation for primary glioblastoma multiforme. Int. J. Radiat. Oncol. Biol. Phys. 2009 Feb 1;73(2):479–85.
24 - Terakawa Y, Tsuyuguchi N, Iwai Y, Yamanaka K, Higashiyama S, Takami T, et al. Diagnostic accuracy of 11C-methionine PET for differentiation of recurrent brain tumors from radiation necrosis after radiotherapy. J. Nucl. Med. 2008 May;49(5):694–9.
25 - Dehdashti F, Mortimer JE, Trinkaus K, Naughton MJ, Ellis M, Katzenellenbogen JA, et al. PET-based estradiol challenge as a predictive biomarker of response to endocrine therapy in women with estrogen-receptor-positive breast cancer. Breast cancer research and treatment. 2009;113(3):509–17.
26 - Peterson LM, Mankoff DA, Lawton T, Yagle K, Schubert EK, Stekhova S, et al. Quantitative imaging of estrogen receptor expression in breast cancer with PET and 18F-fluoroestradiol. Journal of Nuclear Medicine. 2008;49(3):367–74.
27 - Dehdashti F, Picus J, Michalski JM, Dence CS, Siegel BA, Katzenellenbogen JA, et al. Positron tomographic assessment of androgen receptors in prostatic carcinoma. European journal of nuclear medicine and molecular imaging. 2005;32(3):344–50.
28 - Hustinx R, Smith RJ, Benard F, Rosenthal DI, Machtay M, Farber LA, et al. Dual time point fluorine-18 fluorodeoxyglucose positron emission tomography: a potential method to differentiate malignancy from inflammation and normal tissue in the head and neck. European Journal of Nuclear Medicine and Molecular Imaging. 1999;26(10):1345–8.
29 - Matthies A, Hickeson M, Cuchiara A, Alavi A. Dual Time Point 18F-FDG PET for the Evaluation of Pulmonary Nodules. J Nucl Med. 2002 Jul 1;43(7):871–5.
30 - Zhuang H, Pourdehnad M, Lambright ES, Yamamoto AJ, Lanuti M, Li P, et al. Dual Time Point 18F-FDG PET Imaging for Differentiating Malignant from Inflammatory Processes. J Nucl Med. 2001 Sep 1;42(9):1412–7.
31 - Nakamoto Y, Higashi T, Sakahara H, Tamaki N, Kogire M, Doi R, et al. Delayed 18F-fluoro-2-deoxy-D-glucose positron emission tomography scan for differentiation between malignant and benign lesions in the pancreas. Cancer. 2000;89(12):2547–54.
32 - Mertens K, Bolcaen J, Ham H, Deblaere K, Van den Broecke C, Boterberg T, et al. The optimal timing for imaging brain tumours and other brain lesions with 18F-labelled fluoromethylcholine: a dynamic positron emission tomography study. Nucl Med Commun. 2012 Sep;33(9):954–9.
33 - Carlson ER, Schaefferkoetter J, Townsend D, McCoy JM, Campbell PD Jr, Long M. The Use of Multiple Time Point Dynamic Positron Emission Tomography/Computed Tomography in Patients With Oral/Head and Neck Cancer Does Not Predictably Identify Metastatic Cervical Lymph Nodes. Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons [Internet]. 2012 Jun 26 [cited 2012 Sep 28]; Available from:
34 - Nehmeh SA, Erdi YE, Pan T, Pevsner A, Rosenzweig KE, Yorke E, et al. Four-dimensional (4D) PET/CT imaging of the thorax. Med Phys. 2004 Dec;31(12):3179–86.
35 - Nehmeh SA, Erdi YE, Pan T, Yorke E, Mageras GS, Rosenzweig KE, et al. Quantitation of respiratory motion during 4D-PET/CT acquisition. Med Phys. 2004 Jun;31(6):1333–8.
36 - García Vicente AM, Castrejón AS, León Martín AA, García BG, Pilkington Woll JP, Muñoz AP. Value of 4-dimensional 18F-FDG PET/CT in the classification of pulmonary lesions. J Nucl Med Technol. 2011 Jun;39(2):91–9.
37 - Wang Y-C, Hsieh T-C, Yu C-Y, Yen K-Y, Chen S-W, Yang S-N, et al. The clinical application of 4D 18F-FDG PET/CT on gross tumor volume delineation for radiotherapy planning in esophageal squamous cell cancer. J. Radiat. Res. 2012 Jul 1;53(4):594–600.
38 - Mancosu P, Danna M, Bettinardi V, Aquilina MA, Lobefalo F, Cozzi L, et al. Semiautomatic method to identify the best phase for gated RT in lung region by 4D-PET/CT acquisitions. Med Phys. 2011 Jan;38(1):354–62.
39 - Bundschuh RA, Andratschke N, Dinges J, Duma MN, Astner ST, Brügel M, et al. Respiratory gated [18F]FDG PET/CT for target volume delineation in stereotactic radiation treatment of liver metastases. Strahlenther Onkol. 2012 Jul;188(7):592–8.
40 - Aristophanous M, Berbeco RI, Killoran JH, Yap JT, Sher DJ, Allen AM, et al. Clinical utility of 4D FDG-PET/CT scans in radiation treatment planning. Int. J. Radiat. Oncol. Biol. Phys. 2012 Jan 1;82(1):e99–105.
41 - Lucignani G, Paganelli G, Bombardieri E. The use of standardized uptake values for assessing FDG uptake with PET in oncology: a clinical perspective. Nucl Med Commun. 2004 Jul;25(7):651–6.
42 - Huang SC. Anatomy of SUV. Standardized uptake value. Nucl. Med. Biol. 2000 Oct;27(7):643–6.
43 - Wahl RL, Jacene H, Kasamon Y, Lodge MA. From RECIST to PERCIST: Evolving Considerations for PET response criteria in solid tumors. J. Nucl. Med. 2009 May;50 Suppl 1:122S–50S.
44 - Mangona V, Grills I, Wong C, McGee M, Stone B, Hung B, et al. Can Standardized Uptake Value (SUV) Predict Local Failure after Stereotactic or Hyperfractionated Lung Radiotherapy (RT) for Non-small Cell Lung Cancer (NSCLC)? An Evaluation of SUV Kinetics. International Journal of Radiation Oncology* Biology* Physics. 2011;81(2):S167–S168.
45 - Mangona VS, Kestin LL, Yan D, Stone BM, Gustafson BR, Wong CYO, et al. Can 18FDG-PET Predict Local Failure after Stereotactic Body Radiotherapy (SBRT) for Non-Small Cell Lung Cancer (NSCLC)? An Analysis of PET Kinetics. American Journal of Clinical Oncology. 2012;(00):3.
46 - Xiang Z-L, Erasmus J, Komaki R, Cox JD, Chang JY. FDG uptake correlates with recurrence and survival after treatment of unresectable stage III non-small cell lung cancer with high-dose proton therapy and chemotherapy. Radiat Oncol. 2012;7:144.
47 - Kim G, Kim YS, Han EJ, Yoo IR, Song J-H, Lee S-N, et al. FDG-PET/CT as prognostic factor and surveillance tool for postoperative radiation recurrence in locally advanced head and neck cancer. Radiation Oncol J. 2011 Dec;29(4):243–51.
48 - Chan DSY, Fielding P, Roberts SA, Reid TD, Ellis-Owen R, Lewis WG. Prognostic significance of 18-FDG PET/CT and EUS-defined tumour characteristics in patients with oesophageal cancer. Clin Radiol [Internet]. 2012 Sep 13 [cited 2012 Sep 29]; Available from:
49 - Rizk NP, Tang L, Adusumilli PS, Bains MS, Akhurst TJ, Ilson D, et al. Predictive Value of Initial PET-SUVmax in Patients with Locally Advanced Esophageal and Gastroesophageal Junction Adenocarcinoma. Journal of Thoracic Oncology. 2009 Jul;4(7):875–9.
50 - Lee JW, Lee SM, Lee M-S, Shin HC. Role of (18)F-FDG PET/CT in the prediction of gastric cancer recurrence after curative surgical resection. Eur. J. Nucl. Med. Mol. Imaging. 2012 Sep;39(9):1425–34.
51 - Schellenberg D, Quon A, Minn AY, Graves EE, Kunz P, Ford JM, et al. 18Fluorodeoxyglucose PET Is Prognostic of Progression-Free and Overall Survival in Locally Advanced Pancreas Cancer Treated With Stereotactic Radiotherapy. International Journal of Radiation Oncology*Biology*Physics. 2010 Aug;77(5):1420–5.
52 - Kidd EA, El Naqa I, Siegel BA, Dehdashti F, Grigsby PW. FDG-PET-based prognostic nomograms for locally advanced cervical cancer. Gynecol. Oncol. 2012 Oct;127(1):136–40.
53 - Capirci C, Rubello D, Chierichetti F, Crepaldi G, Fanti S, Mandoliti G, et al. Long-Term Prognostic Value of 18F-FDG PET in Patients with Locally Advanced Rectal Cancer Previously Treated with Neoadjuvant Radiochemotherapy. AJR. 2006 Aug 1;187(2):W202–W208.
54 - Kalff V, Duong C, Drummond EG, Matthews JP, Hicks RJ. Findings on 18F-FDG PET Scans After Neoadjuvant Chemoradiation Provides Prognostic Stratification in Patients with Locally Advanced Rectal Carcinoma Subsequently Treated by Radical Surgery. J Nucl Med. 2006 Jan 1;47(1):14–22.
55 - Cazaentre T, Morschhauser F, Vermandel M, Betrouni N, Prangère T, Steinling M, et al. Pre-therapy &lt;sup&gt;18&lt;/sup&gt;F-FDG PET quantitative parameters help in predicting the response to radioimmunotherapy in non-Hodgkin lymphoma. European Journal of Nuclear Medicine and Molecular Imaging. 2010;37(3):494–504.
56 - Schwarzbach MHM, Hinz U, Dimitrakopoulou-Strauss A, Willeke F, Cardona S, Mechtersheimer G, et al. Prognostic Significance of Preoperative [18-F] Fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) Imaging in Patients With Resectable Soft Tissue Sarcomas. Ann Surg. 2005 Feb;241(2):286–94.
57 - Ho K-C, Lin G, Wang J-J, Lai C-H, Chang C-J, Yen T-C. Correlation of apparent diffusion coefficients measured by 3T diffusion-weighted MRI and SUV from FDG PET/CT in primary cervical cancer. European Journal of Nuclear Medicine and Molecular Imaging. 2009;36(2):200–8.
58 - Beaulieu S, Kinahan P, Tseng J, Dunnwald LK, Schubert EK, Pham P, et al. SUV Varies with Time After Injection in 18F-FDG PET of Breast Cancer: Characterization and Method to Adjust for Time Differences. J Nucl Med. 2003 Jul 1;44(7):1044–50.
59 - Berriolo-Riedinger A, Touzery C, Riedinger J-M, Toubeau M, Coudert B, Arnould L, et al. [18F]FDG-PET predicts complete pathological response of breast cancer to neoadjuvant chemotherapy. European Journal of Nuclear Medicine and Molecular Imaging. 2007;34(12):1915–24.
60 - Seol YM, Kwon BR, Song MK, Choi YJ, Shin HJ, Chung JS, et al. Measurement of tumor volume by PET to evaluate prognosis in patients with head and neck cancer treated by chemo-radiation therapy. Acta Oncol. 2010;49(2):201–8.
61 - Lee P, Weerasuriya DK, Lavori PW, Quon A, Hara W, Maxim PG, et al. Metabolic tumor burden predicts for disease progression and death in lung cancer. Int. J. Radiat. Oncol. Biol. Phys. 2007 Oct 1;69(2):328–33.
62 - Hadiprodjo D, Ryan T, Truong M-T, Mercier G, Subramaniam RM. Parotid gland tumors: preliminary data for the value of FDG PET/CT diagnostic parameters. AJR Am J Roentgenol. 2012 Feb;198(2):W185–190.
63 - Hatt M, Visvikis D, Albarghach NM, Tixier F, Pradier O, Cheze-le Rest C. Prognostic value of 18F-FDG PET image-based parameters in oesophageal cancer and impact of tumour delineation methodology. Eur. J. Nucl. Med. Mol. Imaging. 2011 Jul;38(7):1191–202.
64 - Werner-Wasik M, Nelson AD, Choi W, Arai Y, Faulhaber PF, Kang P, et al. What is the best way to contour lung tumors on PET scans? Multiobserver validation of a gradient-based method using a NSCLC digital PET phantom. Int. J. Radiat. Oncol. Biol. Phys. 2012 Mar 1;82(3):1164–71.
65 - Black QC, Grills IS, Kestin LL, Wong C-YO, Wong JW, Martinez AA, et al. Defining a radiotherapy target with positron emission tomography. International Journal of Radiation Oncology*Biology*Physics. 2004 Nov;60(4):1272–82.
66 - Grills IS, Yan D, Black QC, Wong C-YO, Martinez AA, Kestin LL. Clinical implications of defining the gross tumor volume with combination of CT and 18FDG-positron emission tomography in non-small-cell lung cancer. Int. J. Radiat. Oncol. Biol. Phys. 2007 Mar 1;67(3):709–19.
67 - Ettinger D. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) Non-Small Cell Lung Cancer Version 3.2012 [Internet]. National Comprehensive Cancer Network, Inc.; 2012 [cited 2012 Sep 29]. Available from:
68 - Jayachandran P, Pai RK, Quon A, Graves E, Krakow TE, La T, et al. Postchemoradiotherapy positron emission tomography predicts pathologic response and survival in patients with esophageal cancer. Int. J. Radiat. Oncol. Biol. Phys. 2012 Oct 1;84(2):471–7.
69 - Dibble EH, Alvarez ACL, Truong M-T, Mercier G, Cook EF, Subramaniam RM. 18F-FDG metabolic tumor volume and total glycolytic activity of oral cavity and oropharyngeal squamous cell cancer: adding value to clinical staging. J. Nucl. Med. 2012 May;53(5):709–15.
70 - Mangona V, Kestin L, Wong C, McGee M, Hung B, Lurie M, et al. SUV Kinetics of Weekly 18FDG-PET During Radiotherapy Predict Eventual Outcome in Locally-Advanced Non-Small Cell Lung Cancer (NSCLC). International Journal of Radiation Oncology* Biology* Physics. 2012 Nov 1;84(3S):S103–S104.
71 - García Vicente AM, Castrejón ÁS, Relea Calatayud F, Muñoz AP, León Martín AA, López-Muñiz IC, et al. 18F-FDG retention index and biologic prognostic parameters in breast cancer. Clin Nucl Med. 2012 May;37(5):460–6.
72 - Moertel CG, Hanley JA. The effect of measuring error on the results of therapeutic trials in advanced cancer. Cancer. 1976 Jul;38(1):388–94.
73 - Miller AB, Hoogstraten B, Staquet M, Winkler A. Reporting results of cancer treatment. Cancer. 1981 Jan 1;47(1):207–14.
74 - Therasse P, Arbuck SG, Eisenhauer EA, Wanders J, Kaplan RS, Rubinstein L, et al. New guidelines to evaluate the response to treatment in solid tumors. European Organization for Research and Treatment of Cancer, National Cancer Institute of the United States, National Cancer Institute of Canada. J. Natl. Cancer Inst. 2000 Feb 2;92(3):205–16.
75 - Eisenhauer EA, Therasse P, Bogaerts J, Schwartz LH, Sargent D, Ford R, et al. New response evaluation criteria in solid tumours: revised RECIST guideline (version 1.1). Eur. J. Cancer. 2009 Jan;45(2):228–47.
76 - Mohammed N, Grills IS, Wong C-YO, Galerani AP, Chao K, Welsh R, et al. Radiographic and metabolic response rates following image-guided stereotactic radiotherapy for lung tumors. Radiother Oncol. 2011 Apr;99(1):18–22.
77 - Young H, Baum R, Cremerius U, Herholz K, Hoekstra O, Lammertsma AA, et al. Measurement of clinical and subclinical tumour response using [18F]-fluorodeoxyglucose and positron emission tomography: review and 1999 EORTC recommendations. European Organization for Research and Treatment of Cancer (EORTC) PET Study Group. Eur. J. Cancer. 1999 Dec;35(13):1773–82.
78 - Cheson BD, Pfistner B, Juweid ME, Gascoyne RD, Specht L, Horning SJ, et al. Revised response criteria for malignant lymphoma. J. Clin. Oncol. 2007 Feb 10;25(5):579–86.
79 - Cheson BD, Horning SJ, Coiffier B, Shipp MA, Fisher RI, Connors JM, et al. Report of an international workshop to standardize response criteria for non-Hodgkin’s lymphomas. NCI Sponsored International Working Group. J. Clin. Oncol. 1999 Apr;17(4):1244.
80 - Juweid ME, Wiseman GA, Vose JM, Ritchie JM, Menda Y, Wooldridge JE, et al. Response assessment of aggressive non-Hodgkin’s lymphoma by integrated International Workshop Criteria and fluorine-18-fluorodeoxyglucose positron emission tomography. J. Clin. Oncol. 2005 Jul 20;23(21):4652–61.
81 - Minn H, Lapela M, Klemi PJ, Grénman R, Leskinen S, Lindholm P, et al. Prediction of survival with fluorine-18-fluoro-deoxyglucose and PET in head and neck cancer. J. Nucl. Med. 1997 Dec;38(12):1907–11.
82 - Peters LJ, Weber RS, Morrison WH, Byers RM, Garden AS, Goepfert H. Neck surgery in patients with primary oropharyngeal cancer treated by radiotherapy. Head Neck. 1996 Dec;18(6):552–9.
83 - Johnson CR, Silverman LN, Clay LB, Schmidt-Ullrich R. Radiotherapeutic management of bulky cervical lymphadenopathy in squamous cell carcinoma of the head and neck: is postradiotherapy neck dissection necessary? Radiat Oncol Investig. 1998;6(1):52–7.
84 - Yao M, Graham MM, Hoffman HT, Smith RB, Funk GF, Graham SM, et al. The role of post-radiation therapy FDG PET in prediction of necessity for post-radiation therapy neck dissection in locally advanced head-and-neck squamous cell carcinoma. Int. J. Radiat. Oncol. Biol. Phys. 2004 Jul 15;59(4):1001–10.
85 - Yao M, Smith RB, Graham MM, Hoffman HT, Tan H, Funk GF, et al. The role of FDG PET in management of neck metastasis from head-and-neck cancer after definitive radiation treatment. Int. J. Radiat. Oncol. Biol. Phys. 2005 Nov 15;63(4):991–9.
86 - Kubota K, Yokoyama J, Yamaguchi K, Ono S, Qureshy A, Itoh M, et al. FDG-PET delayed imaging for the detection of head and neck cancer recurrence after radio-chemotherapy: comparison with MRI/CT. Eur. J. Nucl. Med. Mol. Imaging. 2004 Apr;31(4):590–5.
87 - Rogers JW, Greven KM, McGuirt WF, Keyes JW Jr, Williams DW 3rd, Watson NE, et al. Can post-RT neck dissection be omitted for patients with head-and-neck cancer who have a negative PET scan after definitive radiation therapy? Int. J. Radiat. Oncol. Biol. Phys. 2004 Mar 1;58(3):694–7.
88 - Porceddu SV, Jarmolowski E, Hicks RJ, Ware R, Weih L, Rischin D, et al. Utility of positron emission tomography for the detection of disease in residual neck nodes after (chemo)radiotherapy in head and neck cancer. Head & Neck. 2005;27(3):175–81.
89 - Fogarty GB, Peters LJ, Stewart J, Scott C, Rischin D, Hicks RJ. The usefulness of fluorine 18-labelled deoxyglucose positron emission tomography in the investigation of patients with cervical lymphadenopathy from an unknown primary tumor. Head Neck. 2003 Feb;25(2):138–45.
90 - Isles MG, McConkey C, Mehanna HM. A systematic review and meta-analysis of the role of positron emission tomography in the follow up of head and neck squamous cell carcinoma following radiotherapy or chemoradiotherapy. Clin Otolaryngol. 2008 Jun;33(3):210–22.
91 - Ferlito A, Corry J, Silver CE, Shaha AR, Thomas Robbins K, Rinaldo A. Planned neck dissection for patients with complete response to chemoradiotherapy: a concept approaching obsolescence. Head Neck. 2010 Feb;32(2):253–61.
92 - Gupta T, Master Z, Kannan S, Agarwal JP, Ghsoh-Laskar S, Rangarajan V, et al. Diagnostic performance of post-treatment FDG PET or FDG PET/CT imaging in head and neck cancer: a systematic review and meta-analysis. Eur. J. Nucl. Med. Mol. Imaging. 2011 Nov;38(11):2083–95.
93 - Pryor DI, Porceddu SV, Scuffham PA, Whitty JA, Thomas PA, Burmeister BH. Economic analysis of FDG-PET-guided management of the neck after primary chemoradiotherapy for node-positive head and neck squamous cell carcinoma. Head Neck. 2012 Sep 18;
94 - Adjuvant radiotherapy for rectal cancer: a systematic overview of 8,507 patients from 22 randomised trials. Lancet. 2001 Oct 20;358(9290):1291–304.
95 - Improved survival with preoperative radiotherapy in resectable rectal cancer. Swedish Rectal Cancer Trial. N. Engl. J. Med. 1997 Apr 3;336(14):980–7.
96 - Sauer R, Becker H, Hohenberger W, Rödel C, Wittekind C, Fietkau R, et al. Preoperative versus postoperative chemoradiotherapy for rectal cancer. N. Engl. J. Med. 2004 Oct 21;351(17):1731–40.
97 - Janjan NA, Abbruzzese J, Pazdur R, Khoo VS, Cleary K, Dubrow R, et al. Prognostic implications of response to preoperative infusional chemoradiation in locally advanced rectal cancer. Radiother Oncol. 1999 May;51(2):153–60.
98 - Janjan NA, Khoo VS, Abbruzzese J, Pazdur R, Dubrow R, Cleary KR, et al. Tumor downstaging and sphincter preservation with preoperative chemoradiation in locally advanced rectal cancer: the M. D. Anderson Cancer Center experience. Int. J. Radiat. Oncol. Biol. Phys. 1999 Jul 15;44(5):1027–38.
99 - Hoffmann K-T, Rau B, Wust P, Stroszczynski C, Hünerbein M, Schneider U, et al. Restaging of locally advanced carcinoma of the rectum with MR imaging after preoperative radio-chemotherapy plus regional hyperthermia. Strahlenther Onkol. 2002 Jul;178(7):386–92.
100 - Capirci C, Rampin L, Erba PA, Galeotti F, Crepaldi G, Banti E, et al. Sequential FDG-PET/CT reliably predicts response of locally advanced rectal cancer to neo-adjuvant chemo-radiation therapy. Eur. J. Nucl. Med. Mol. Imaging. 2007 Oct;34(10):1583–93.
101 - Calvo FA, Domper M, Matute R, Martínez-Lázaro R, Arranz JA, Desco M, et al. 18F-FDG positron emission tomography staging and restaging in rectal cancer treated with preoperative chemoradiation. Int. J. Radiat. Oncol. Biol. Phys. 2004 Feb 1;58(2):528–35.
102 - Capirci C, Rubello D, Pasini F, Galeotti F, Bianchini E, Del Favero G, et al. The role of dual-time combined 18-fluorodeoxyglucose positron emission tomography and computed tomography in the staging and restaging workup of locally advanced rectal cancer, treated with preoperative chemoradiation therapy and radical surgery. Int. J. Radiat. Oncol. Biol. Phys. 2009 Aug 1;74(5):1461–9.
103 - Kristiansen C, Loft A, Berthelsen AK, Graff J, Lindebjerg J, Bisgaard C, et al. PET/CT and histopathologic response to preoperative chemoradiation therapy in locally advanced rectal cancer. Dis. Colon Rectum. 2008 Jan;51(1):21–5.
104 - Guillem JG, Moore HG, Akhurst T, Klimstra DS, Ruo L, Mazumdar M, et al. Sequential preoperative fluorodeoxyglucose-positron emission tomography assessment of response to preoperative chemoradiation: a means for determining longterm outcomes of rectal cancer. J. Am. Coll. Surg. 2004 Jul;199(1):1–7.
105 - Perez RO, Habr-Gama A, São Julião GP, Gama-Rodrigues J, Sousa AHS Jr, Campos FG, et al. Optimal Timing for Assessment of Tumor Response to Neoadjuvant Chemoradiation in Patients With Rectal Cancer: Do All Patients Benefit From Waiting Longer Than 6 Weeks? International journal of radiation oncology, biology, physics. 2012 May 12;
106 - Francois Y, Nemoz CJ, Baulieux J, Vignal J, Grandjean JP, Partensky C, et al. Influence of the interval between preoperative radiation therapy and surgery on downstaging and on the rate of sphincter-sparing surgery for rectal cancer: the Lyon R90-01 randomized trial. J. Clin. Oncol. 1999 Aug;17(8):2396.
107 - Tulchinsky H, Shmueli E, Figer A, Klausner JM, Rabau M. An interval >7 weeks between neoadjuvant therapy and surgery improves pathologic complete response and disease-free survival in patients with locally advanced rectal cancer. Ann. Surg. Oncol. 2008 Oct;15(10):2661–7.
108 - Schaefer NG, Hany TF, Taverna C, Seifert B, Stumpe KDM, von Schulthess GK, et al. Non-Hodgkin lymphoma and Hodgkin disease: coregistered FDG PET and CT at staging and restaging--do we need contrast-enhanced CT? Radiology. 2004 Sep;232(3):823–9.
109 - 109. Hutchings M, Loft A, Hansen M, Pedersen LM, Berthelsen AK, Keiding S, et al. Position emission tomography with or without computed tomography in the primary staging of Hodgkin’s lymphoma. Haematologica. 2006 Jan 1;91(4):482–9.
110 - Pakos EE, Fotopoulos AD, Ioannidis JPA. 18F-FDG PET for Evaluation of Bone Marrow Infiltration in Staging of Lymphoma: A Meta-Analysis. J Nucl Med. 2005 Jun 1;46(6):958–63.
111 - Hoppe RT. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) Hodgkin Lymphoma Version 2.2012 [Internet]. National Comprehensive Cancer Network, Inc.; 2012 [cited 2012 Oct 14]. Available from:
112 - Zelenetz AD. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) Non-Hodgkin’s Lymphoma Version 3.2012 [Internet]. National Comprehensive Cancer Network, Inc.; 2012 [cited 2012 Oct 14]. Available from:
113 - Cheson BD. Role of functional imaging in the management of lymphoma. J. Clin. Oncol. 2011 May 10;29(14):1844–54.
114 - Jerusalem G, Beguin Y, Fassotte MF, Najjar F, Paulus P, Rigo P, et al. Whole-body positron emission tomography using 18F-fluorodeoxyglucose for posttreatment evaluation in Hodgkin’s disease and non-Hodgkin’s lymphoma has higher diagnostic and prognostic value than classical computed tomography scan imaging. Blood. 1999 Jul 15;94(2):429–33.
115 - Spaepen K, Stroobants S, Dupont P, Thomas J, Vandenberghe P, Balzarini J, et al. Can positron emission tomography with [18F]-fluorodeoxyglucose after first-line treatment distinguish Hodgkin’s disease patients who need additional therapy from others in whom additional therapy would mean avoidable toxicity? British Journal of Haematology. 2001;115(2):272–8.
116 - Spaepen K, Stroobants S, Dupont P, Van Steenweghen S, Thomas J, Vandenberghe P, et al. Prognostic value of positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose ([18F]FDG) after first-line chemotherapy in non-Hodgkin’s lymphoma: is [18F]FDG-PET a valid alternative to conventional diagnostic methods? J. Clin. Oncol. 2001 Jan 15;19(2):414–9.
117 - Halasz LM, Jacene HA, Catalano PJ, Van den Abbeele AD, Lacasce A, Mauch PM, et al. Combined Modality Treatment for PET-Positive Non-Hodgkin Lymphoma: Favorable Outcomes of Combined Modality Treatment for Patients With Non-Hodgkin Lymphoma and Positive Interim or Postchemotherapy FDG-PET. Int. J. Radiat. Oncol. Biol. Phys. 2012 Aug 1;83(5):e647–654.
118 - Cerci JJ, Trindade E, Pracchia LF, Pitella FA, Linardi CCG, Soares J Jr, et al. Cost effectiveness of positron emission tomography in patients with Hodgkin’s lymphoma in unconfirmed complete remission or partial remission after first-line therapy. J. Clin. Oncol. 2010 Mar 10;28(8):1415–21.
119 - Engert A, Haverkamp H, Kobe C, Markova J, Renner C, Ho A, et al. Reduced-intensity chemotherapy and PET-guided radiotherapy in patients with advanced stage Hodgkin’s lymphoma (HD15 trial): a randomised, open-label, phase 3 non-inferiority trial. Lancet. 2012 May 12;379(9828):1791–9.
120 - Bangerter M, Moog F, Buchmann I, Kotzerke J, Griesshammer M, Hafner M, et al. Whole-body 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for accurate staging of Hodgkin’s disease. Ann. Oncol. 1998 Oct;9(10):1117–22.
121 - Zinzani PL, Magagnoli M, Chierichetti F, Zompatori M, Garraffa G, Bendandi M, et al. The role of positron emission tomography (PET) in the management of lymphoma patients. Ann. Oncol. 1999 Oct;10(10):1181–4.
122 - Mikhaeel NG, Timothy AR, Hain SF, O’Doherty MJ. 18-FDG-PET for the assessment of residual masses on CT following treatment of lymphomas. Ann. Oncol. 2000;11 Suppl 1:147–50.
123 - Naumann R, Vaic A, Beuthien-Baumann B, Bredow J, Kropp J, Kittner T, et al. Prognostic value of positron emission tomography in the evaluation of post-treatment residual mass in patients with Hodgkin’s disease and non-Hodgkin’s lymphoma. Br. J. Haematol. 2001 Dec;115(4):793–800.
124 - Gigli F, Nassi L, Negri M, others. Interim 18f [FDG] positron emission tomography in patients with diffuse large B-cell lymphoma. Blood. 2008;112:1234.
125 - Cashen AF, Dehdashti F, Luo J, Homb A, Siegel BA, Bartlett NL. 18F-FDG PET/CT for early response assessment in diffuse large B-cell lymphoma: poor predictive value of international harmonization project interpretation. J. Nucl. Med. 2011 Mar;52(3):386–92.
126 - Cerci JJ, Pracchia LF, Linardi CCG, Pitella FA, Delbeke D, Izaki M, et al. 18F-FDG PET after 2 cycles of ABVD predicts event-free survival in early and advanced Hodgkin lymphoma. J. Nucl. Med. 2010 Sep;51(9):1337–43.
127 - Hutchings M, Mikhaeel NG, Fields PA, Nunan T, Timothy AR. Prognostic value of interim FDG-PET after two or three cycles of chemotherapy in Hodgkin lymphoma. Ann. Oncol. 2005 Jul;16(7):1160–8.
128 - Kostakoglu L, Goldsmith SJ, Leonard JP, Christos P, Furman RR, Atasever T, et al. FDG-PET after 1 cycle of therapy predicts outcome in diffuse large cell lymphoma and classic Hodgkin disease. Cancer. 2006 Dec 1;107(11):2678–87.
129 - Zinzani PL, Tani M, Fanti S, Alinari L, Musuraca G, Marchi E, et al. Early positron emission tomography (PET) restaging: a predictive final response in Hodgkin’s disease patients. Ann. Oncol. 2006 Aug;17(8):1296–300.
130 - Gallamini A, Hutchings M, Rigacci L, Specht L, Merli F, Hansen M, et al. Early interim 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography is prognostically superior to international prognostic score in advanced-stage Hodgkin’s lymphoma: a report from a joint Italian-Danish study. J. Clin. Oncol. 2007 Aug 20;25(24):3746–52.
131 - Markova J, Kobe C, Skopalova M, Klaskova K, Dedeckova K, Plütschow A, et al. FDG-PET for assessment of early treatment response after four cycles of chemotherapy in patients with advanced-stage Hodgkin’s lymphoma has a high negative predictive value. Ann. Oncol. 2009 Jul;20(7):1270–4.
132 - Spaepen K, Stroobants S, Dupont P, Vandenberghe P, Thomas J, de Groot T, et al. Early restaging positron emission tomography with ( 18)F-fluorodeoxyglucose predicts outcome in patients with aggressive non-Hodgkin’s lymphoma. Ann. Oncol. 2002 Sep;13(9):1356–63.
133 - Haioun C, Itti E, Rahmouni A, Brice P, Rain J-D, Belhadj K, et al. [18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in aggressive lymphoma: an early prognostic tool for predicting patient outcome. Blood. 2005 Aug 15;106(4):1376–81.
134 - Mikhaeel NG, Hutchings M, Fields PA, O’Doherty MJ, Timothy AR. FDG-PET after two to three cycles of chemotherapy predicts progression-free and overall survival in high-grade non-Hodgkin lymphoma. Ann. Oncol. 2005 Sep;16(9):1514–23.
135 - Ng AP, Wirth A, Seymour JF, Lee M, Hogg A, Januszewicz H, et al. Early therapeutic response assessment by (18)FDG-positron emission tomography during chemotherapy in patients with diffuse large B-cell lymphoma: isolated residual positivity involving bone is not usually a predictor of subsequent treatment failure. Leuk. Lymphoma. 2007 Mar;48(3):596–600.
136 - Han HS, Escalón MP, Hsiao B, Serafini A, Lossos IS. High incidence of false-positive PET scans in patients with aggressive non-Hodgkin’s lymphoma treated with rituximab-containing regimens. Ann. Oncol. 2009 Feb;20(2):309–18.
137 - Pregno P, Chiappella A, Bellò M, Botto B, Ferrero S, Franceschetti S, et al. Interim 18-FDG-PET/CT failed to predict the outcome in diffuse large B-cell lymphoma patients treated at the diagnosis with rituximab-CHOP. Blood. 2012 Mar 1;119(9):2066–73.
138 - Safar V, Dupuis J, Itti E, Jardin F, Fruchart C, Bardet S, et al. Interim [18F]fluorodeoxyglucose positron emission tomography scan in diffuse large B-cell lymphoma treated with anthracycline-based chemotherapy plus rituximab. J. Clin. Oncol. 2012 Jan 10;30(2):184–90.
139 - Zinzani PL, Gandolfi L, Broccoli A, Argnani L, Fanti S, Pellegrini C, et al. Midtreatment 18F-fluorodeoxyglucose positron-emission tomography in aggressive non-Hodgkin lymphoma. Cancer. 2011 Mar 1;117(5):1010–8.
140 - Kobe C, Dietlein M, Franklin J, Markova J, Lohri A, Amthauer H, et al. Positron emission tomography has a high negative predictive value for progression or early relapse for patients with residual disease after first-line chemotherapy in advanced-stage Hodgkin lymphoma. Blood. 2008 Nov 15;112(10):3989–94.
141 - Engert A, Diehl V, Franklin J, Lohri A, Dörken B, Ludwig W-D, et al. Escalated-dose BEACOPP in the treatment of patients with advanced-stage Hodgkin’s lymphoma: 10 years of follow-up of the GHSG HD9 study. J. Clin. Oncol. 2009 Sep 20;27(27):4548–54.
142 - Refaely Y, Krasna MJ. Multimodality therapy for esophageal cancer. Surg. Clin. North Am. 2002 Aug;82(4):729–46.
143 - Stahl M, Budach W, Meyer H-J, Cervantes A. Esophageal cancer: Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann. Oncol. 2010 May;21 Suppl 5:v46–49.
144 - Merkow RP, Bilimoria KY, McCarter MD, Chow WB, Ko CY, Bentrem DJ. Use of multimodality neoadjuvant therapy for esophageal cancer in the United States: assessment of 987 hospitals. Ann. Surg. Oncol. 2012 Feb;19(2):357–64.
145 - Bosset JF, Gignoux M, Triboulet JP, Tiret E, Mantion G, Elias D, et al. Chemoradiotherapy followed by surgery compared with surgery alone in squamous-cell cancer of the esophagus. N. Engl. J. Med. 1997 Jul 17;337(3):161–7.
146 - Urba SG, Orringer MB, Turrisi A, Iannettoni M, Forastiere A, Strawderman M. Randomized trial of preoperative chemoradiation versus surgery alone in patients with locoregional esophageal carcinoma. J. Clin. Oncol. 2001 Jan 15;19(2):305–13.
147 - Le Prise E, Etienne PL, Meunier B, Maddern G, Ben Hassel M, Gedouin D, et al. A randomized study of chemotherapy, radiation therapy, and surgery versus surgery for localized squamous cell carcinoma of the esophagus. Cancer. 1994 Apr 1;73(7):1779–84.
148 - Walsh TN, Noonan N, Hollywood D, Kelly A, Keeling N, Hennessy TP. A comparison of multimodal therapy and surgery for esophageal adenocarcinoma. N. Engl. J. Med. 1996 Aug 15;335(7):462–7.
149 - van Hagen P, Hulshof MCCM, van Lanschot JJB, Steyerberg EW, Henegouwen MI van B, Wijnhoven BPL, et al. Preoperative Chemoradiotherapy for Esophageal or Junctional Cancer. New England Journal of Medicine. 2012;366(22):2074–84.
150 - Berger AC, Farma J, Scott WJ, Freedman G, Weiner L, Cheng JD, et al. Complete Response to Neoadjuvant Chemoradiotherapy in Esophageal Carcinoma Is Associated With Significantly Improved Survival. JCO. 2005 Jul 1;23(19):4330–7.
151 - Weber WA, Ott K, Becker K, Dittler HJ, Helmberger H, Avril NE, et al. Prediction of response to preoperative chemotherapy in adenocarcinomas of the esophagogastric junction by metabolic imaging. J. Clin. Oncol. 2001 Jun 15;19(12):3058–65.
152 - Wieder HA, Brücher BLDM, Zimmermann F, Becker K, Lordick F, Beer A, et al. Time Course of Tumor Metabolic Activity During Chemoradiotherapy of Esophageal Squamous Cell Carcinoma and Response to Treatment. JCO. 2004 Mar 1;22(5):900–8.
153 - Wieder HA, Ott K, Lordick F, Becker K, Stahl A, Herrmann K, et al. Prediction of tumor response by FDG-PET: comparison of the accuracy of single and sequential studies in patients with adenocarcinomas of the esophagogastric junction. Eur. J. Nucl. Med. Mol. Imaging. 2007 Dec;34(12):1925–32.
154 - Downey RJ, Akhurst T, Ilson D, Ginsberg R, Bains MS, Gonen M, et al. Whole Body 18FDG-PET and the Response of Esophageal Cancer to Induction Therapy: Results of a Prospective Trial. JCO. 2003 Feb 1;21(3):428–32.
155 - Kostakoglu L, Goldsmith SJ. PET in the Assessment of Therapy Response in Patients with Carcinoma of the Head and Neck and of the Esophagus*. J Nucl Med. 2004 Jan 1;45(1):56–68.
156 - Weber WA. Use of PET for Monitoring Cancer Therapy and for Predicting Outcome. J Nucl Med. 2005 Jun 1;46(6):983–95.
157 - Chao KS. Functional imaging for early prediction of response to chemoradiotherapy: 3’-deoxy-3’-18F-fluorothymidine positron emission tomography-A clinical application model of esophageal cancer. Seminars in oncology [Internet]. 2006 [cited 2012 Oct 7]. Available from:
158 - Levine EA, Farmer MR, Clark P, Mishra G, Ho C, Geisinger KR, et al. Predictive Value of 18-Fluoro-Deoxy-Glucose-Positron Emission Tomography (18F-FDG-PET) in the Identification of Responders to Chemoradiation Therapy for the Treatment of Locally Advanced Esophageal Cancer. Ann Surg. 2006 Apr;243(4):472–8.
159 - Roedl JB, Colen RR, Holalkere NS, Fischman AJ, Choi NC, Blake MA. Adenocarcinomas of the esophagus: Response to chemoradiotherapy is associated with decrease of metabolic tumor volume as measured on PET–CT. Radiotherapy and Oncology. 2008 Dec;89(3):278–86.
160 - Kwee RM. Prediction of Tumor Response to Neoadjuvant Therapy in Patients with Esophageal Cancer with Use of 18F FDG PET: A Systematic Review1. Radiology. 2010 Mar 1;254(3):707–17.
161 - Kauppi JT, Oksala N, Salo JA, Helin H, Karhumäki L, Kemppainen J, et al. Locally advanced esophageal adenocarcinoma: Response to neoadjuvant chemotherapy and survival predicted by [18F] FDG-PET/CT. Acta Oncologica. 2012 May;51(5):636–44.
162 - Ishihara R, Yamamoto S, Iishi H, Nagai K, Matui F, Kawada N, et al. Predicting the effects of chemoradiotherapy for squamous cell carcinoma of the esophagus by induction chemotherapy response assessed by positron emission tomography: toward PET-response-guided selection of chemoradiotherapy or esophagectomy. Int. J. Clin. Oncol. 2012 Jun;17(3):225–32.
163 - Yanagawa M, Tatsumi M, Miyata H, Morii E, Tomiyama N, Watabe T, et al. Evaluation of response to neoadjuvant chemotherapy for esophageal cancer: PET response criteria in solid tumors versus response evaluation criteria in solid tumors. J. Nucl. Med. 2012 Jun;53(6):872–80.
164 - Monjazeb AM, Riedlinger G, Aklilu M, Geisinger KR, Mishra G, Isom S, et al. Outcomes of patients with esophageal cancer staged with [18F]fluorodeoxyglucose positron emission tomography (FDG-PET): can postchemoradiotherapy FDG-PET predict the utility of resection? J. Clin. Oncol. 2010 Nov 1;28(31):4714–21.
165 - Mohammed N, Kestin LL, Grills IS, Battu M, Fitch DL, Wong C-YO, et al. Rapid disease progression with delay in treatment of non-small-cell lung cancer. Int. J. Radiat. Oncol. Biol. Phys. 2011 Feb 1;79(2):466–72.
166 - Edet-Sanson A, Dubray B, Doyeux K, Back A, Hapdey S, Modzelewski R, et al. Serial assessment of FDG-PET FDG uptake and functional volume during radiotherapy (RT) in patients with non-small cell lung cancer (NSCLC). Radiotherapy and Oncology. 2012 Feb;102(2):251–7.
167 - Kong F-MS, Frey KA, Quint LE, Haken RKT, Hayman JA, Kessler M, et al. A Pilot Study of [18F]Fluorodeoxyglucose Positron Emission Tomography Scans During and After Radiation-Based Therapy in Patients With Non–Small-Cell Lung Cancer. JCO. 2007 Jul 20;25(21):3116–23.
168 - van Baardwijk A, Bosmans G, Dekker A, van Kroonenburgh M, Boersma L, Wanders S, et al. Time trends in the maximal uptake of FDG on PET scan during thoracic radiotherapy. A prospective study in locally advanced non-small cell lung cancer (NSCLC) patients. Radiotherapy and Oncology. 2007 Feb;82(2):145–52.
169 - Vera P, Bohn P, Edet-Sanson A, Salles A, Hapdey S, Gardin I, et al. Simultaneous positron emission tomography (PET) assessment of metabolism with 18F-fluoro-2-deoxy-d-glucose (FDG), proliferation with 18F-fluoro-thymidine (FLT), and hypoxia with 18fluoro-misonidazole (F-miso) before and during radiotherapy in patients with non-small-cell lung cancer (NSCLC): A pilot study. Radiotherapy and Oncology. 2011 Jan;98(1):109–16.
170 - Hicks RJ. Role of 18F-FDG PET in Assessment of Response in Non-Small Cell Lung Cancer. Journal of Nuclear Medicine. 2009 Apr 20;50(Suppl_1):31S–42S.
171 - Nahmias C, Hanna WT, Wahl LM, Long MJ, Hubner KF, Townsend DW. Time Course of Early Response to Chemotherapy in Non–Small Cell Lung Cancer Patients with 18F-FDG PET/CT. J Nucl Med. 2007 May 1;48(5):744–51.
172 - Vansteenkiste JF, Stroobants SG, Leyn PRD, Dupont PJ, Verbeken EK. Potential use of FDG-PET scan after induction chemotherapy in surgically staged IIIa–N2 non-small-cell lung cancer: A prospective pilot study. Ann Oncol. 1998 Nov 1;9(11):1193–8.
173 - Manus MPM, Hicks RJ, Matthews JP, McKenzie A, Rischin D, Salminen EK, et al. Positron Emission Tomography Is Superior to Computed Tomography Scanning for Response-Assessment After Radical Radiotherapy or Chemoradiotherapy in Patients With Non–Small-Cell Lung Cancer. JCO. 2003 Apr 1;21(7):1285–92.
174 - Weber WA, Petersen V, Schmidt B, Tyndale-Hines L, Link T, Peschel C, et al. Positron emission tomography in non-small-cell lung cancer: prediction of response to chemotherapy by quantitative assessment of glucose use. J. Clin. Oncol. 2003 Jul 15;21(14):2651–7.
175 - Hellwig D, Graeter TP, Ukena D, Georg T, Kirsch C-M, Schäfers H-J. Value of F-18-fluorodeoxyglucose positron emission tomography after induction therapy of locally advanced bronchogenic carcinoma. J. Thorac. Cardiovasc. Surg. 2004 Dec;128(6):892–9.
176 - Eschmann SM, Friedel G, Paulsen F, Reimold M, Hehr T, Budach W, et al. 18F-FDG PET for assessment of therapy response and preoperative re-evaluation after neoadjuvant radio-chemotherapy in stage III non-small cell lung cancer. Eur. J. Nucl. Med. Mol. Imaging. 2007 Apr;34(4):463–71.
177 - de Geus-Oei L-F, van der Heijden HFM, Visser EP, Hermsen R, van Hoorn BA, Timmer-Bonte JNH, et al. Chemotherapy response evaluation with 18F-FDG PET in patients with non-small cell lung cancer. J. Nucl. Med. 2007 Oct;48(10):1592–8.
178 - Tanvetyanon T, Eikman EA, Sommers E, Robinson L, Boulware D, Bepler G. Computed tomography response, but not positron emission tomography scan response, predicts survival after neoadjuvant chemotherapy for resectable non-small-cell lung cancer. J. Clin. Oncol. 2008 Oct 1;26(28):4610–6.
179 - Baschnagel A, Mangona VS, Robertson J, Ye H, Kestin L, Grills I. Lung metastases treated with image-guided stereotactic body radiation therapy. International Journal of Radiation Oncology Biology Physics. 2010;78(3):5.
180 - Grills IS, Hope AJ, Guckenberger M, Kestin LL, Werner-Wasik M, Yan D, et al. A Collaborative Analysis of Stereotactic Lung Radiotherapy Outcomes for Early-Stage Non-Small-Cell Lung Cancer Using Daily Online Cone-Beam Computed Tomography Image-Guided Radiotherapy. Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer [Internet]. 2012 Jul 26 [cited 2012 Aug 14]; Available from:
181 - Grills IS, Mangona VS, Welsh R, Chmielewski G, McInerney E, Martin S, et al. Outcomes after stereotactic lung radiotherapy or wedge resection for stage I non-small-cell lung cancer. J. Clin. Oncol. 2010 Feb 20;28(6):928–35.
182 - Welsh R, Grills I, Deraniyagala R, Kestin L, Baschnagel A, Mangona V, et al. Lobectomy, Wedge Resection, or Stereotactic Radiotherapy (SBRT) for Stage I Non-small Cell Lung Cancer: Which Treatment Yields the Best Outcome? International Journal of Radiation Oncology* Biology* Physics. 2010;78(3):S180–S180.
183 - Onishi H, Shirato H, Nagata Y, Hiraoka M, Fujino M, Gomi K, et al. Stereotactic body radiotherapy (SBRT) for operable stage I non-small-cell lung cancer: can SBRT be comparable to surgery? Int. J. Radiat. Oncol. Biol. Phys. 2011 Dec 1;81(5):1352–8.
184 - Timmerman R, Paulus R, Galvin J, Michalski J, Straube W, Bradley J, et al. Stereotactic body radiation therapy for inoperable early stage lung cancer. JAMA. 2010 Mar 17;303(11):1070–6.
185 - Guckenberger M, Kestin LL, Hope AJ, Belderbos J, Werner-Wasik M, Yan D, et al. Is there a lower limit of pretreatment pulmonary function for safe and effective stereotactic body radiotherapy for early-stage non-small cell lung cancer? J Thorac Oncol. 2012 Mar;7(3):542–51.
186 - Ohri N, Werner-Wasik M, Grills IS, Belderbos J, Hope A, Yan D, et al. Modeling local control after hypofractionated stereotactic body radiation therapy for stage I non-small cell lung cancer: a report from the elekta collaborative lung research group. Int. J. Radiat. Oncol. Biol. Phys. 2012 Nov 1;84(3):e379–384.
187 - Lanni TB Jr, Grills IS, Kestin LL, Robertson JM. Stereotactic radiotherapy reduces treatment cost while improving overall survival and local control over standard fractionated radiation therapy for medically inoperable non-small-cell lung cancer. Am. J. Clin. Oncol. 2011 Oct;34(5):494–8.
188 - Stone B, Grills I, Mangona V, Ye H, Martin S, Wloch J, et al. Changes in Pulmonary Function Following Imaged Guided Stereotactic Radiotherapy of the Lung. International Journal of Radiation Oncology* Biology* Physics. 2011;81(2):S611.
189 - Mangona V, Grills I, Yan D, McInerney E, Martin S, Kestin L, et al. Predictors of Pulmonary and Other Thoracic Complications after Lung Stereotactic Body Radiotherapy (SBRT) for Primary or Metastatic Lung Tumors: Dose–volume Analysis. International Journal of Radiation Oncology* Biology* Physics. 2009;75(3):S161–S161.
190 - Grills IS, Hugo G, Kestin LL, Galerani AP, Chao KK, Wloch J, et al. Image-Guided Radiotherapy via Daily Online Cone-Beam CT Substantially Reduces Margin Requirements for Stereotactic Lung Radiotherapy. International Journal of Radiation Oncology*Biology*Physics. 2008 Mar;70(4):1045–56.
191 - Galerani AP, Grills I, Hugo G, Kestin L, Mohammed N, Chao KK, et al. Dosimetric impact of online correction via cone-beam CT-based image guidance for stereotactic lung radiotherapy. Int. J. Radiat. Oncol. Biol. Phys. 2010 Dec 1;78(5):1571–8.
192 - McGee M, Grills I, Mangona V, Ionascu D, Margolis J, Welsh R, et al. Feasibility, Toxicity, and Early Outcomes for Dose-escalated 4D Adaptive Image-guided Radiotherapy (IGRT) for Non-small Cell Lung Cancer (NSCLC). International Journal of Radiation Oncology* Biology* Physics. 2011;81(2):S165–S166.
193 - Shaitelman S, Grills I, Liang J, Zhuang L, Mangona V, Yan D, et al. A Comprehensive Dose-Volume Analysis of Predictors of Pneumonitis and Esophagitis Following Radiotherapy for Non-Small Cell Lung Cancer (NSCLC). Esophagus. 2009;10:5.
194 - Grills IS, Mangona VS. Intensity-Modulated Radiation Therapy and Volumetric-Modulated Arc Therapy for Lung Cancer. Advances in Radiation Oncology in Lung Cancer. 2011;691–713.
195 - Kong F-M. Using FDG-PET During Radiation Therapy in Non-Small Cell Lung Cancer (HUM15709) [Internet]. Available from:
196 - Kong F-M (Spring). RTOG 1106/ACRIN 6697 Randomized Phase Ii Trial of Individualized Adaptive Radiotherapy Using During-Treatment FDG-PET/CT And Modern Technology in Locally Advanced Non-Small Cell Lung Cancer (Nsclc) [Internet]. 2012 [cited 2012 Oct 16]. Available from: