Open access peer-reviewed chapter

An Overview of PET Radiopharmaceuticals in Clinical Use: Regulatory, Quality and Pharmacopeia Monographs of the United States and Europe

Written By

Ya-Yao Huang

Submitted: 25 February 2018 Reviewed: 31 May 2018 Published: 05 November 2018

DOI: 10.5772/intechopen.79227

From the Edited Volume

Nuclear Medicine Physics

Edited by Aamir Shahzad and Sajid Bashir

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Abstract

Since 1976, more and more PET radiopharmaceuticals have been developed as the clinical introduction of [18F]FDG for various medical applications. However, few of them could be involved in routinely clinical use in hospitals partly because of restrictions in regulatory and facilities. This chapter aims to provide an overview of PET radiopharmaceuticals that are common manufactured (or prepared) in industry (or hospitals) about regulatory and quality aspects, and further summarize pharmacopeia-listed PET radiopharmaceuticals and their clinical usefulness herein. Particularly, PET radiopharmaceuticals listed in latest United States Pharmacopeia (USP) and/or European Pharmacopeia (EP) are included for this chapter. Finally, this chapter would be helpful in the basic understanding of clinical PET radiopharmaceuticals for physicians or technologists.

Keywords

  • PET
  • radiopharmaceutical
  • regulation
  • quality
  • clinical application
  • USP
  • EP
  • pharmacopeia

1. Introduction

Positron emission tomography (PET) radiopharmaceutical is composed of a biologically active pharmacophore and a positron-emitting radionuclide, and belongs to a unique species in pharmaceutical field. The most common radionuclides for PET radiopharmaceuticals include 11C, 15O, 13N, 18F, 68Ga and 82Rb (Table 1). In addition to radiation issue, short half-lives of these positron emitters (78 sec~110 min) definitely result in unavoidable limitations on manufacturing (including production and following quality control (QC) analyses) and clinical use of PET radiopharmaceuticals. Above are all practical challenges for a conventional pharmaceutical industry. Hence, commercial large-scale manufacturing and small-scale preparation of PET radiopharmaceuticals are respectively allowed in radiopharmaceutical industries and the radiopharmacy of hospitals in most countries worldwide. Moreover, both practices in radiopharmaceutical industries and hospitals are clearly regulated by national competence authorities, such as Food and Drug Administration (FDA) of the United States (U.S.) and European Medicines Agency (EMA) of the European Union (EU).

Radionuclide Half-life Max
specific activity (Ci/μmol)
ß+
(%)
Max Eß (MeV) Max ß+ range (mm) Production route
11C 20 min 9220 99 0.96 4.1 Cyclotron
15O 123 sec 90,800 100 1.19 5.1 Cyclotron
13N 10 min 18,900 100 1.72 7.3 Cyclotron
18F 110 min 1710 97 0.635 2.4 Cyclotron
68Ga 68 min 2766 88 1.9 8.2 Cyclotron/ Generator
82Rb 78 sec 150,400 95 3.35 14.1 Generator

Table 1.

Characteristics of common positron emitters.

In the other hand, a pharmacopeia is a national compendium of drug quality standards, such as U.S. Pharmacopeia (USP) and European Pharmacopeia (EP), and is always recognized as an official compendium. Drug standards listed in pharmacopeia monographs are usually enforced to be compliance under drug-related provisions at national level in order to prevent the marketing of inconsistent drugs and to reduce possible risks in public health. Although PET radiopharmaceuticals listing in pharmacopeia monographs sometimes do not mean for marketing authorization under national approval and reimbursement decision of medical insurance [1], some countries have enabled the clinical use (i.e., use for routine patient care with/without reimbursement or with/without national approval) or clinical trials as long as their qualities are in conformity with USP or EP standards, even no good manufacturing practice (GMP)-compliant process. Moreover, for those clinical studies using national-approved PET radiopharmaceutical for off-label indications, burdensome submission of an investigational new drug (IND) application will not be required in some countries.

In the other hand, specific QC procedures and specification of some PET radiopharmaceuticals have been listed in USP or EP. However, because of short half-lives of PET radiopharmaceuticals, QC tests prior to human administration within such a short period is a huge challenge. As a result, some quality exceptions are usually allowed for PET radiopharmaceuticals. Also, several efficient and quick tests have been developed for rapid QC tests of clinical PET radiopharmaceuticals.

This chapter first aims to provide an overview of regulations of manufacturing and clinical use of PET radiopharmaceuticals in U.S. and Europe. Secondly, the chapter will introduce the general quality aspect for PET radiopharmaceuticals. Finally, this chapter will end with the brief introduction of PET radiopharmaceuticals listed in the monographs of latest USP (USP 40) or EP (EP 9.0) (Table 2).

Radionuclide Compound USP EP
11C [11C]CO *
[11C-methyl]Methionine *
N-[11C-methyl]Flumazenil *
[11C]N-methylspiroperidol *
[11C-methoxy]Raclopride *
[1-11C]Sodium Acetate *
13N [13N]NH3
15O [15O]CO
[15O]H2O *
18F [18F]FCH
[18F]FDG
[18F]FDOPA (prepared by electrophilic substitution) *
[18F]FET
[18F]FLT
[18F]FMISO
[18F]NaF
68Ga [68Ga]Ga-Citrate
[68Ga]Ga-DOTA-TOC
82Rb [82Rb]rubidium chloride

Table 2.

PET radiopharmaceuticals listed in USP and EP.

These monographs of 8 FDA-unapproved PET radiopharmaceuticals have been omitted from USP since May 1, 2015 (USP 38).


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2. Regulatory aspects of PET radiopharmaceuticals in the USA and Europe

2.1. USA regulatory view

In U.S., the clinical use of all radiopharmaceuticals has been regulated by FDA since 1975. Briefly, the regulatory process can be divided into two types. They are: 1. IND submission for investigational and research purposes by an individual or a commercial manufacturer, and 2. submissions of Notice of Claimed Investigational Exemption (NCIE), an abbreviated new drug application (ANDA) or New Drug Application (NDA) for commercial marketing only by a commercial manufacturer. However, because of the increasing clinical need of PET radiopharmaceuticals, based on FDA Modernization Act (FDAMA) in 1997 [2], PET radiopharmaceuticals were first categorized as positron-emitting drugs. In the same time, all PET radiopharmaceutical manufacturing facilities in U.S. were programmatically to compliant with PET drug GMP-compliance guideline or with USP General Chapter <823> [3], and further registered as manufacturers. Till now, these legal manufacturers could on-site (in-house) produced PET radiopharmaceuticals with same specifications listed in USP monographs.

In the other hand, USP is annually published by a nonprofit organization since 1820, U.S. Pharmacopeial Convention, and such organization also worked with FDA and specialists in academia and companies to establish monographs or general chapters. Typically, USP monographs are typically developed after FDA approval of the drug product for commercial marketing and thus a USP monograph of an FDA-approved drug has been used as one basis for a reimbursement decision. The first USP monograph for a PET drug was published in 1990 [4] and it described the quality specification and analytic methods for [18F]FDG injection. However, there had been an exception for 4 approved and 8 unapproved PET drugs listed in USP monographs till 2013. Moreover, not only these 12 monographs were provided to U.S. Pharmacopeial Convention by various academic sponsors with un-validated data and outdated analytic methods, but also these unapproved 8 PET drugs have limited commercial application without FDA-approved NDA or ANDA. Consequently, based on recommendations of the Society of Nuclear Medicine and Molecular Imaging (SNMMI) Committee [1], U.S. Pharmacopeial Convention announced the omission of the monographs of 8 unapproved PET drugs on June 2014 and the omission initiative became official on December 1, 2014.

2.2. European regulatory view

In Europe, radiopharmaceuticals have been recognized as a special group of medicines. Thus, the preparation and clinical use of PET radiopharmaceuticals have been regulated and variously adopted by member states. Similar to USP, EP has legal status in Europe. Compared to the USA, EP is only for drug quality and is independent of licensing status or clinical utility of such drug. Regarding to PET radiopharmaceuticals, corresponding monographs are elaborated by a group that is composed of academic, commercial and regulatory specialists. From another point of view, a number of EU member states have set up a regulatory framework from the definitions of “magistral and officinal formulae” that is listed in Article 3 of Directive 2001/83 [5]. Additionally, “in-house” small-scale preparation of PET radiopharmaceuticals is allowed without the requirements of a marketing authorization based on various national laws of European countries [5]. Both a general chapter of EP entitled “Extemporaneous Preparation of Radiopharmaceuticals” [6] and the new PIC/S guidance document with Annex 3 on radiopharmaceuticals [7] are published and worked as comprehensive guidelines for such magistral approach. Furthermore, because of the special characteristics of PET radiopharmaceuticals, the clinical studies using diagnostic radiopharmaceuticals do not fall within the GMP-compliance regulations of conventional drugs from EU Regulation no 536/2014 of 16 April 2014 [8, 9]. On brief summary, no matter EP or PIC/S document, they both clearly define a clear distinction between PET radiopharmaceuticals and conventional medicine, and further provide the corresponding guidance. All would be significantly helpful and powerful in promotion and development of PET radiopharmaceuticals in Europe.

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3. Quality aspects of PET radiopharmaceuticals

Even costly implementation and maintenance of quality system for a PET radiopharmaceutical manufacturing (or preparing) site [10, 11], it is still thought to be cost-effective [12]. Moreover, it will be helpful for qualified patient care, regulatory requirements, optimization of safety and efficacy for patient care and a reliable quantitative performance in both diagnostic and therapeutic nuclear medicine procedures [13]. Therefore, GMP-compliant PET manufacturing (or preparing) process including production, QC, quality assurance (QA), package and distribution has been required by competent authorities in many countries worldwide. Furthermore, during these years, the concept of “Quality by Design (QbD)” based on guidelines of International Conference on Harmonization (ICH) (ICH Q8 [14], ICH Q9 [15], and ICH Q10 [16]) has been the fundamental topic in pharmaceutical field and an appropriate quality system has been widely required to implement in many radiopharmaceutical manufacturing sites (Figure 1). Briefly, QA covers whole process and GMP specifically characterizes those production and QC activities that guarantee products are produced under the constant scrutiny of quality standards [17], although the association of QA, GMP, and QC throughout whole pharmaceutical process is slightly different in various guidelines.

Figure 1.

The inter-relationship for whole quality system in PET radiopharmaceutical manufacturing.

Particularly, QC procedure of PET radiopharmaceutical is usually critical and essential, since it is synthesized every day or is small-scale “prepared “in radiopharmacy of a hospital. A typical QC programme of a PET radiopharmaceutical is involved from radionuclide production to final product release and a series of QC tests for PET radiopharmaceuticals basically include:

  1. Appearance, by visual assessment;

  2. pH determination;

  3. Radionuclidic identification, by gamma-ray spectrometry or half-life measurement;

  4. Radionuclidic purity, by gamma-ray spectrometry;

  5. Chemical purity, by high-pressure liquid chromatography (HPLC) or by thin-layer chromatography (TLC);

  6. Radiochemical purity, by HPLC with a radioactivity detector or by TLC with a radioactivity scanner;

  7. Residual solvents, by gas chromatography (GC);

  8. Bacterial endotoxins, by a rabbit test or limulus amebocyte lysate (LAL) test;

  9. Radioactivity, by a validated dose calibrator and.

  10. Sterility, by incubating the sample with fluid thioglycollate medium (FTM) at 30~35°C for 14 days or with soybean casein digest (SCD) medium at 20~25°C for 14 days.

However, because of short-lives of PET radiopharmaceuticals, some lengthy tests cannot be performed prior to release for human use and are allowable to perform within a short time after the release. Furthermore, in addition to the limited time for QC of PET radiopharmaceuticals, limited personneal for in-house preparing of PET radiopharmaceuticals is another major issue for a hospital. Therefore, more and more efficient systems have been developed and successfully implemented for clinical use, such as Endosafe® Portable Testing System™ (PTS™) for rapid endotoxin testing (Charles River, Wilmington, MA) (https://www.criver.com/products-services/qc-microbial-solutions/endotoxin-testing/endotoxin-testing-systems/endosafe-nexgen-pts?region=3681) and Tracer-QC system for automation of QC tests of PET radiopharmaceuticals (LabLogic Systems Ltd., Sheffield, UK) (https://lablogic.com/nuclear-medicine-and-pet/instruments/tracer-qc).

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4. Overview of current PET radiopharmaceuticals listed in USP or EP

4.1. [11C-methyl]Methionine injection (EP)

Cellular protein synthesis is a well-control process for enzymes, membrane receptors, structural proteins, and growth factors [18]. Most importantly, increased cellular protein synthesis is often characterized in malignant growth [19]. Otherwise, decreased protein synthesis is found in certain neurodegenerative disorders [20]. Thus, the ability to in vivo visualize the protein synthesis rate is critical for clinic. Protein synthesis is initiated universally with the amino acid, methionine [21]. Therefore, one of 11C-labeled methionine analogs, [11C-methyl]methionine ([11C]MET) [22] (Figure 2), has been used for imaging of rate of protein synthesis [23, 24], although the short physical half-life of 11C (20 min) limits its accessibility for PET scanning centers without a cyclotron. Clinically, [11C]MET has been used in imaging of brain, urinary, gynecological, liver and lung cancer [25, 26, 27, 28]. Particularly, the enhanced transport of [11C]MET into the brain has been known via the reversible sodium-independent transport system L (LAT 1) since 1995 [28] and increased LAT1 expression has been found in glioma and many other cancers and is associated with high grade and poor prognosis [29, 30, 31, 32], thus [11C]MET has been widely in various brain tumors [33, 34].

Figure 2.

Chemical structures of PET radiopharmaceuticals listed in this chapter.

4.2. N-[11C-methyl]Flumazenil injection (EP)

The GABAA/benzodiazepine receptor complex is also known as the central benzodiazepine receptor and specifically mediates all pharmacologic properties of ethanol, zinc, picrotoxin and some drugs such as benzodiazepines (sedative, anxiolytic, anticonvulsant, myorelaxant), barbiturates (cerebral protection) and neuroactive steroids [35]. Based on a benzodiazepine antagonist, N-[11C-methyl]Flumazenil ([11C]FMZ) (Figure 2) [36] has been developed and known for its excellent kinetic properties for the image quantification [37]. Moreover, [11C]FMZ has been considered as a versatile PET tracer for assessment of several conditions, such as neuronal damage in head injury [38], epilepsy [39], stroke-induced penumbral areas of infarction [40] and Alzheimer’s disease (AD) [41].

4.3. [11C-methoxy]Raclopride injection (EP)

Dopamine (DA) plays an important role in every-day brain functions including experiencing pleasure, regulating attention, and learning to control urges. Dysfunction of DA circuits has been thought to be related to various psychiatric diseases such as Parkinson’s diseases (PD), addiction, attention-deficit hyperactivity disorder, and schizophrenia [42]. Studying in vivo dopamine function in humans became possible in the mid-1990s with the development of [11C]raclopride (Figure 2) [43, 44], which originates from a DA receptor antagonist (D2/D3) with moderate affinity and reversible binding characteristics. Up to now, [11C]raclopride is the most widely used PET radiopharmaceutical for measuring DA changes in striatal dopamine levels in the synapse before and after pharmacological and behavioral challenges [45], such as aging [46, 47, 48], schizophrenia [49, 50, 51, 52, 53] and PD [54, 55].

4.4. [1-11C]sodium acetate injection (EP)

Acetate is a molecule quickly picked-up by cells to convert into acetyl-CoA by acetyl-CoA synthetase (EC 6.2.1.1 according to Enzyme Commission Number) and participates in cytoplasmic lipid synthesis, which is believed to be increased in tumors. Thus, [1-11C] Sodium Acetate ([11C]Ac) (Figure 2) [56, 57] has been proved clinical usefulness in prostate cancer (PC) [58], hepatocellular carcinoma (HCC), lung cancer, nasopharyngeal carcinoma [33], renal cell carcinoma, bladder carcinoma and brain tumors [59]. Furthermore, [11C]Ac has been used to clinically measure myocardial oxygen consumption since 2010 [60] and used in some rare conditions, such as thymoma, cerebellopontine angle schwannoma, angiomyolipoma of the kidney, encephalitis, and multiple myeloma [59].

4.5. [13N]NH3 injection (USP and EP)

Coronary flow reserve (CFR) is calculated as the ratio of hyperemic to rest absolute myocardial blood flow (MBF) and is a particularly useful parameter in the assessment of adverse cardiovascular events such as epicardial coronary stenosis, diffuse atherosclerosis, and microvascular dysfunction on myocardial tissue perfusion [61]. Routinely used [13N]Ammonia ([13N]NH3) is not only a useful 13N-labeled PET imaging agent for assessing regional blood flow in tissues [62], but a well-validated radiotracer for clinical management of patients with coronary artery disease [62, 63, 64]. Moreover, recently [13N]NH3 has been used in PC, because the up-regulation of NH3 during de novo glutamine synthesis was known in tumors [65]. Furthermore, because excess circulating NH3 is neurotoxic and hyperammonemia is thought to be a major factor in the encephalopathy associated with several diseases, such as liver cirrhosis [66, 67, 68], [13N]NH3 is also used for elucidation of NH3 metabolism in patients with hepatic encephalopathy [69].

4.6. [15O]CO injection (EP)

[15O]CO is one of the most common tracers used for noninvasively measuring oxygen consumption and blood volume [70, 71]. Additionally, [15O]CO is crucial for the evaluation of acute stroke patients. Moreover, measurement of myocardial oxygen consumption is a useful tool to clarify the relationship between MBF and oxygen extraction fraction (OEF), because both OEF and MBF are important indicators in describing myocardial function [72].

4.7. [15O]H2O injection (EP)

Although the short half-life (123 sec) of 15O results in the challenges in clinical use, [15O]H2O is still the preferred tracer because of its ease production from generator, effectiveness and safety for patient use [73]. Particularly, PET with [15O]H2O has been a standard method and most reliable approach for quantitative measurement of cerebral blood flow (CBF). Also, [15O]H2O is capable to clinically investigate cerebral and myocardial perfusion [74], and tumor perfusion [75, 76].

4.8. [18F]FCH injection (EP)

Choline is a precursor for the biosynthesis of phospholipids which are essential components of all membranes and is phosphorylated by choline kinase (CK) to produce phosphatidylcholine. Upregulated CK is known in cancer cells, thus it further leads to increased uptake of choline in tumor cells with the excess need for phospholipid biosynthesis [77, 78]. Consequently, 18F-labeled choline analogs, [18F]fluoromethylcholine ([18F]FCH) (Figure 2) [79, 80] has been a promising tumor imaging agents for various types of tumors include brain [80], breast, thyroid, lung, liver and prostate [81]. Particularly, [18F]FCH has been shown to be better than [18F]FDG for PC and HCC detections [81].

4.9. [18F]FDG injection (USP and EP)

Since its synthesis in 1976, 2-fluorine-[18F]fluorodeoxyglucose ([18F]FDG) [82] (Figure 2) has been the most widely used radiotracer for PET studies in neuroscience, cardiology and oncology (Table 3) [83]. After FDA approval in 1997, [18F]FDG with PET or PET/CT scanner became an established imaging tool in the clinical assessment of many neoplasms, as well as the nonmalignant diseases including dementia, myocardial ischaemia, inflammation and infection [84].

Classification Disease Application
Neurology Alzheimer’s Disease
Epilepsy Pre-surgical evaluation for epileptogenic foci (85–90% accuracy).
Cardiology Myocardial Viability Assessment of myocardial viability prior to cardiac surgery
Identify high-risk patients Select patients who will benefit from bypass
Psychiatry Schizophrenia
Depression
Oncology Tumor Evaluation Differentiate recurrent/residual tumor from necrosis.
Tumor Staging Malignant vs. benign. Lung nodules, primary breast and colon cancers.
Tumor Monitoring Response to therapy.
Tumor Localization Metastases, abnormal sites
Infection and Inflammation Orthopedic infections

Table 3.

Summary for clinical application of [18F]FDG [83].

4.10. [18F]FDOPA (prepared by electrophilic substitution) injection (EP)

Dihydroxyphenylalanine (DOPA) has been known as an intermediate in the catecholamine synthesis pathway. One of the 18F-radiolabeled analogs, 3,4-dihydroxy-6-[18F]fluoro-L-phenylalanine ([18F]FDOPA) (Figure 2), was first reported as a PET tracer for imaging pre-synaptic dopaminergic functions in 1983 [85]. Subsequent studies revealed the utility of [18F]FDOPA for the visualization of various peripheral tumor entities via PET [86], which can be attributed to the up-regulation of amino acid transporters in malignant tissues due to an often increased proliferation [87]. In particular, because of the relationship between the expression of aromatic L-amino acid decarboxylase (AADC) and the metabolism of [18F]FDOPA [88, 89], [18F]FDOPA has shown diagnostic advantages in the imaging of neuroendocrine cell-related malignancies like neuroendocrine tumors (NETs) [89, 90, 91, 92, 93, 94], pheochromocytoma [95, 96, 97], pancreatic adenocarcinoma [98, 99] and neuroblastoma (NB) [100, 101, 102] regarding diagnostic efficiency and sensitivity.

4.11. [18F]FET injection (EP)

Na+-independent system L amino acid transporters (LATs) preferentially transports amino acids with large neutral side chains, including L-leucine, L-phenylalanine, and L-tyrosine. O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET) (Figure 2) [103] belongs to the class of large neutral amino acids, which are transported via specific amino acid transporters especially of LATs [104]. Although data today still not reveal which the transporter(s) responsible for [18F]FET accumulation in cells [105], [18F]FET has been well known for its high uptake in brain tumors and its potential for grading tumors particularly gliomas [106, 107]. Summarily, [18F]FET has been well-investigated in differential diagnosis, grading, prognostication, treatment response assessment, and differentiating pseudoprogression from non-specific post-therapeutic changes [108, 109, 110]. Switzerland was the first country to approve [18F]FET PET for clinical use in brain tumor imaging since 2014 [105].

4.12. [18F]FLT ([18F]Alovudine) injection (EP)

Cellular proliferation plays an important role in cancer and has been an important imaging target of PET radiopharmaceuticals, especially with the aim targeting of DNA synthesis. Since the approach to the measurement of DNA synthesis in humans was explored in the early 1970s, based on an antiviral agent developed by Medivir, [18F]fluorothymidine ([18F]FLT, also known as [18F]Alovudine) (Figure 2) [111, 112] has been designed with intracellularly trapping of its phosphorylated metabolite within cells [113]. Up to now, [18F]FLT has been widely investigated in oncologic setting comprising tumor detection, staging, restaging, and response assessment to treatment [114, 115, 116] and [18F]FLT imaging has several clinical advantages including noninvasive procedure, three-dimensional tumor images and simultaneous detection of multiple tumor sites [117]. Also, [18F]FLT is capable to evaluate tumor heterogeneity in day-to-day practice [118].

4.13. [18F]FMISO injection (EP)

Hypoxia means insufficient oxygen availability of a cell occurring both in health and is acknowledged by the observation of Gray et al. in the mid-1950s [119, 120]. Hypoxia is an important prognostic indicator of response to either chemotherapy or radiation therapy in cancer management [121, 122]. Hypoxia is also an independent factor for predicting the metastases tendency of a tumor cell, because of its enhancement in DNA mutations of atypical cells and further appearance of more aggressive cells. Consequently, 1-(2-hydroxy-3-[18F]fluoropropyl)-2-nitroimidazole ([18F]FMISO) (Figure 2) [123, 124] is the most established agent for assessing hypoxia and has been used for cancer imaging over the past 30 y for glioblastoma multiforme, non-small-cell lung cancer, and head and neck tumors [125]. In addition, high accuracy of [18F]FMISO PET imaging for determining the duration of survival without relapses and for predicting the radiotherapy efficiency in patients with malignant tumors of various localizations has been reported [126, 127]. Furthermore, prognostic potential of [18F]FMISO for the pretherapeutic tumor oxygenation status has been confirmed for glioblastoma multiforme, head and neck cancer, lung cancer, breast cancer, pancreatic cancer, gynecologic cancers, cervical cancer and sarcoma [127].

4.14. [18F]NaF injection (USP and EP)

The bone is the most common place of tumor metastases next to the lung and liver [128]. Therefore, early and accurate diagnosis of the metastatic bone diseases thus plays an important role for an establishment of adequate therapeutic strategy [129]. [18F]Sodium fluoride ([18F]NaF) was introduced in 1962 and approved by FDA in 1972 [130]. [18F]NaF is a high sensitive bone-seeking PET radiopharmaceutical and is considered as an excellent substitute for traditionally used 99mTc-labeled tracers, because its favorable characteristics of negligible protein binding, and rapid blood pool clearance. With 99mTc supply around the world is gradually become a crisis due to the shortage of 99Mo-source material [131, 132], the clinical use of [18F]NaF keeps increasing worldwide. Additionally, uptake of [18F]NaF reflects blood flow and bone remodeling [133], and [18F]NaF have been proposed for the use in detection of benign and malignant osseous abnormalities that also allows the regional characterization of lesions in metabolic bone diseases [134, 135].

4.15. [68Ga]Ga-citrate injection(EP)

In addition to war and famine, bacterial infection has still been one of major worldwide causes for human morbidity and mortality for centuries [136, 137]. Because of the trapping of gallium in the extravascular compartment for inflammatory or infectious sites with the increased capillary permeability [138], and the iron-like binding characteristics in bacterial siderophores and activated lactoferrin in neutrophils [139, 140], gallium is thought to be indirectly uptaken by macrophages [141, 142] or directly uptaken by bacteria [143]. Thus, [67Ga]gallium citrate ([68Ga]Ga-Citrate) has been used for clinical imaging of infection and inflammation since 1984 [144]. The utilities of [68Ga]Ga-Citrate include the monitoring of osteomyelitis, diskitis, intra-abdominal infection, tuberculosis and interstitial nephritis, as well as the localization of infection in patients with cellulitis and abscesses [145, 146].

4.16. [68Ga]Ga-DOTA-TOC injection (EP)

NETs arised from neuroendocrine cells and are one of slow-growing tumors with year-by-year increased incidence rate and 75% of overall 5-y survival, which is strongly dependent on stage and grade of the tumor [147]. Because NETs has been known for its unique overexpression of somatostatin receptors (SSTrs) on the tumor cells [148], SSTr-targeting PET radiopharmaceuticals provide a promising and useful approach for both diagnostic imaging and further peptide receptor radionuclide therapy (PRRT), such as 68Ga-labeled DOTA-(Tyr3)-octreotide acetate ([68Ga]Ga-DOTA-TOC) (Figure 2) [149]. Because octreotide is a subset of the amino acid in somatostatin and has been demonstrated to avidly bind to SSTr [150], [68Ga]Ga-DOTA-TOC has been recognized for its affinity toward both the type 2 somatostatin receptor (SSTr2) and the type 5 somatostatin receptor (SSTr5) [151, 152, 153, 154]. Also, [68Ga]Ga-DOTA-TOC was the first PET radiopharmaceutical to clinically localize to NETs in 2001 [155] and has been widely used in Europe and several other countries to assist the therapy planning and accurate diagnosis of NETs patients [156]. In addition, [68Ga]Ga-DOTA-TOC is valuable for neuroectodermal tumors, Hurthle cell thyroid carcinoma, prostate cancer patients with bone metastases and autoimmune thyroid disease like Graves’ disease and Hashimoto’s disease [145, 146].

4.17. [82Rb]rubidium chloride (USP)

Just like previous described [13N]NH3 and [15O]H2O, [82Rb]Rubidium chloride ([82Rb]RbCl) has been reported for directly proportional relationship between its uptake and MBF since 1954 [157]. In addition, several studies have demonstrated the good diagnostic accuracy of [82Rb]RbCl in monitoring of cardiac flow [158, 159]. Subsequently, 82Sr/82Rb generator (CardioGen-82®) of Bracco Diagnostics has been approved by FDA for clinical cardiac imaging since 1989 (NDA 19–414). Therefore, production and administration of [82Rb]RbCl can be well coordinated with the 82Sr/82Rb generator in clinic [160], although a short half-life (78 sec) of 82Rb. In brief, the clinical advantages of [82Rb]RbCl cardiac imaging include its capacity to accurately quantify MBF and a low delivered radiation exposure for a rest/stress test resulted from its very short half-life [160].

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5. Conclusion

With the development of imaging technology, more and more pharmaceutical industry and hospitals worldwide have paid attentions on clinical potential of PET radiopharmaceuticals. However, because of special characteristics of PET radiopharmaceuticals, current pharmaceutical regulatory is probably inapplicable and would be a hurdle for clinical use of PET radiopharmaceuticals in most countries. Thus, as these official monographs of PET radiopharmaceuticals listing in USP or EP, it is definitely worthy to work together for more pharmacopeia monographs and a PET radiopharmaceutical-specific regulatory for benefits of patient-centered care in the future.

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Acknowledgments

This work has been supported in part by grants from the National Taiwan University Hospital, Grants NTUH107-S3882.

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Conflict of interest

We declare no conflict of interest.

References

  1. 1. Schwarz S, Norenberg J, Berridge M, et al. The future of USP monographs for PET drugs. Journal of Nuclear Medicine. 2013;54(3):472-475
  2. 2. Food and Drug Administration Modernization Act of 1997. Washington, DC: Congress US; 1997
  3. 3. USP. Positron emission tomography drugs for compounding, investigational, and research uses, USP<823>. In: The United States Pharmacopeia, 40th Rev., and the National Formulary, 35th Ed. 40 Ed. Rockville, MD: United States Pharmacopeial Convention, Inc.; 2017. pp. 758-768
  4. 4. U.S. Pharmacopeial Convention. USP 22–NF 17, Fludeoxyglucose F 18 Injection. Rockville, MD: U.S. Pharmacopeial Convention; 1990:579-580
  5. 5. Decristoforo C, Patt M. Are we “preparing” radiopharmaceuticals? EJNMMI Radiopharmacy and Chemistry. 2017;2(1):12
  6. 6. EP9.0. 5.19. Extemporaneous preparation of radiopharmaceuticals. European Pharmacopeia. 8th ed. Strasbourg, France United States Pharmacopeial Convention, Inc.; 2017:767-772
  7. 7. Pharmaceutical Inspection Co-operation Scheme. PIC/S guide to good practices for the preparation of medicinal products in healthcare establishments. PE 010-4. Geneva: Pharmaceutical Inspection Co-operation Scheme; 2014. Available from: www.picscheme.org
  8. 8. Decristoforo C, Penuelas I, Elsinga P, et al. Radiopharmaceuticals are special, but is this recognized? The possible impact of the new clinical trials regulation on the preparation of radiopharmaceuticals. European Journal of Nuclear Medicine and Molecular Imaging. 2014;41(11):2005-2007
  9. 9. Ballinger JR, Koziorowski J. Regulation of PET radiopharmaceuticals production in Europe. In: Khalil MM, editor. Basic Science of PET Imaging. Egypt: Springer; 2017. pp. 127-143
  10. 10. Bergmann H, Busemann-Sokole E, Horton P. Quality assurance and harmonisation of nuclear medicine investigations in Europe. European Journal of Nuclear Medicine. 1995;22(5):477-480
  11. 11. Liu K-T, Zhao J-H, Men L-C, Chen C-H. Quality by design and risk assessment for radiopharmaceutical manufacturing and clinical imaging. In: Akyar I, editor. Latest Research into Quality Control. IntechOpen; 2012. pp. 255-292. DOI: 10.5772/51112. Available from: https://www.intechopen.com/books/latest-research-into-quality-control/quality-by-design-and-risk-assessment-for-radiopharmaceutical-manufacturing-and-clinical-imaging
  12. 12. Chuck A, Jacobs P, Logus J, St Hilaire D, Chmielowiec C, McEwan A. Marginal cost of operating a positron emission tomography center in a regulatory environment. International Journal of Technology Assessment in Health Care. 2005;21(4):442-451
  13. 13. Zimmerman B, Herbst C, Norenberg J, Woods M. International guidance on the establishment of quality assurance programmes for radioactivity measurement in nuclear medicine. Applied Radiation and Isotopes. 2006;64(10-11):1142-1146
  14. 14. International Conference on Harmonisation. ICH Harmonised Tripartite Guideline: Pharmaceutical Development Q8 (R2). http://www.ich.org/fileadmin/Public_Web_Site/ICH_Products/Guidelines/Quality/Q8_R1/Step4/Q8_R2_Guideline.pdf
  15. 15. International Conference on Harmonisation. ICH Harmonised Tripartite Guideline, Quality Risk Management, Q9. http://www.ich.org/fileadmin/Public_Web_Site/ICH_Products/Guidelines/Quality/Q9/Step4/Q9_Guideline.pdf
  16. 16. International Conference on Harmonisation. ICH Harmonised Tripartite Guideline, Pharmaceutical Quality System, Q10. http://www.ich.org/fileadmin/Public_Web_Site/ICH_Products/Guidelines/Quality/Q10/Step4/Q10_Guideline.pdf
  17. 17. US Pharmacopeial Convention. Ensuring the Quality of Medicines in Resource-Limited Countries. https://www.usp-pqm.org/sites/default/files/pqms/article/ensuringqualityoperationalguide.pdf
  18. 18. Sonenberg N, Hinnebusch AG. Regulation of translation initiation in eukaryotes: Mechanisms and biological targets. Cell. 2009;136(4):731-745
  19. 19. Bhat M, Robichaud N, Hulea L, Sonenberg N, Pelletier J, Topisirovic I. Targeting the translation machinery in cancer. Nature Reviews. Drug Discovery. 2015;14(4):261-278
  20. 20. Halliday M, Mallucci GR. Modulating the unfolded protein response to prevent neurodegeneration and enhance memory. Neuropathology and Applied Neurobiology. 2015;41(4):414-427
  21. 21. Kozak M. Comparison of initiation of protein synthesis in procaryotes, eucaryotes, and organelles. Microbiological Reviews. 1983;47(1):1-45
  22. 22. Langstrom B, Antoni G, Gullberg P, et al. Synthesis of L-and D-[methyl-11C] methionine. Journal of Nuclear Medicine. 1987;28(6):1037-1040
  23. 23. Hawkins R, Huang S, Barrio J, et al. Estimation of local cerebral protein synthesis rates with L-[1-11C] leucine and PET: Methods, model, and results in animals and humans. Journal of Cerebral Blood Flow and Metabolism. 1989;9(4):446-460
  24. 24. Ishiwata K, Vaalburg W, Elsinga P, Paans A, Woldring M. Comparison of L-[1-11C]methionine and L-methyl-[11C] methionine for measuring in vivo protein synthesis rates with PET. Journal of Nuclear Medicine. 1988;29(8):1419-1427
  25. 25. Nunez R, Macapinlac H, Yeung H, et al. Combined 18F-FDG and 11C-methionine PET scans in patients with newly progressive metastatic prostate cancer. Journal of Nuclear Medicine. 2002;43(1):46-55
  26. 26. Wood K, Hoskin P, Saunders M. Positron emission tomography in oncology: A review. Clinical Oncology (Royal College of Radiologists). 2007;19(4):237-255
  27. 27. Kuang Y, Wang F, Corn DJ, Tian H, Lee Z. Metabolism of Radiolabeled Methionine in Hepatocellular carcinoma. Molecular Imaging and Biology. 2014;16(1):44-52
  28. 28. Lilja A, Bergström K, Hartvig P, et al. Dynamic study of supratentorial gliomas with L-methyl-11C-methionine and positron emission tomography. AJNR. American Journal of Neuroradiology. 1985;6(4):505-514
  29. 29. Nawashiro H, Otani N, Shinomiya N, et al. L-type amino acid transporter 1 as a potential molecular target in human astrocytic tumors. International Journal of Cancer. 2006;119(3):484-492
  30. 30. Betsunoh H, Fukuda T, Anzai N, et al. Increased expression of system large amino acid transporter (LAT)-1 mRNA is associated with invasive potential and unfavorable prognosis of human clear cell renal cell carcinoma. BMC Cancer. 2013;13:509
  31. 31. Kaira K, Sunose Y, Arakawa K, et al. Prognostic significance of L-type amino-acid transporter 1 expression in surgically resected pancreatic cancer. British Journal of Cancer. 2012;107(4):632-638
  32. 32. Takeuchi K, Ogata S, Nakanishi K, et al. LAT1 expression in non-small-cell lung carcinomas: Analyses by semiquantitative reverse transcription-PCR (237 cases) and immunohistochemistry (295 cases). Lung Cancer. 2010;68(1):58-65
  33. 33. Pantaleo M, Nannini M, Maleddu A, et al. Conventional and novel PET tracers for imaging in oncology in the era of molecular therapy. Cancer Treatment Reviews. 2008;34(2):103-121
  34. 34. Juhász C, Dwivedi S, Kamson DO, Michelhaugh SK, Mittal S. Comparison of amino acid positron emission Tomographic radiotracers for molecular imaging of primary and metastatic brain tumors. Molecular Imaging. 2014;13. DOI: 10.2310/7290.2014.00015
  35. 35. Heiss W, Herholz K. Brain receptor imaging. Journal of Nuclear Medicine. 2006;47(2):302-312
  36. 36. Maziere M, Prenant C, Sastre J, et al. 11C-RO-15-1788 et 11C-flunitrazepam, deux coordinats pour l'etude par tomographie par positrons des sites de liaison des benzodiazepines. Comptes rendus de l'Académie des Sciences (Paris). 1983;296:871-876
  37. 37. Koeppe R, Holthoff V, Frey K, Kilbourn M, Kuhl D. Compartmental analysis of [11C]flumazenil kinetics for the estimation of ligand transport rate and receptor distribution using positron emission tomography. Journal of Cerebral Blood Flow and Metabolism. 1991;11(5):735-744
  38. 38. Geeraerts T, Coles J, Aigbirhio F, et al. Validation of reference tissue modelling for [11C]flumazenil positron emission tomography following head injury. Annals of Nuclear Medicine. 2011;25(6):396-405
  39. 39. Lamusuo S, Pitkänen A, Jutila L, et al. [11C]Flumazenil binding in the medial temporal lobe in patients with temporal lobe epilepsy: Correlation with hippocampal MR volumetry, T2 relaxometry, and neuropathology. Neurology. 2000;54(12):2252-2260
  40. 40. Heiss W, Sobesky J, Smekal U, et al. Probability of cortical infarction predicted by flumazenil binding and diffusion-weighted imaging signal intensity: A comparative positron emission tomography/magnetic resonance imaging study in early ischemic stroke. Stroke. 2004;35(8):1892-1898
  41. 41. Pascual B, Prieto E, Arbizu J, et al. Decreased carbon-11-flumazenil binding in early Alzheimer's disease. Brain. 2012;135(Pt 9):2817-2825
  42. 42. Dichter GS, Damiano CA, Allen JA. Reward circuitry dysfunction in psychiatric and neurodevelopmental disorders and genetic syndromes: Animal models and clinical findings. Journal of Neurodevelopmental Disorders. 2012;4(1):19
  43. 43. Ehrin E, Gawell L, Hogberg T, de Paulis T, Strom P. Synthesis of [methoxy-3H]-and [methoxy-11C]-labelled raclopride. Specific dopamine-D2 receptor ligands. Journal of Labelled Compounds and Radiopharmaceuticals. 1987;24(8):931-940
  44. 44. Farde L, Ehrin E, Eriksson L, et al. Substituted benzamides as ligands for visualization of dopamine receptor binding in the human brain by positron emission tomography. Proceedings of the National Academy of Sciences of the United States of America. 1985;82(11):3863-3867
  45. 45. Egerton A, Mehta MA, Montgomery AJ, et al. The dopaminergic basis of human behaviors: A review of molecular imaging studies. Neuroscience and Biobehavioral Reviews. 2009;33(7):1109-1132
  46. 46. Pohjalainen T, Rinne J, Nagren K, SyvAlahti E, Hietala J. Sex differences in the striatal dopamine D2 receptor binding characteristics in vivo. American Journal of Psychiatry Research. 1998;155(6):768-773
  47. 47. Volkow N, Wang G, Fowler J, et al. Measuring age-related changes in dopamine D2 receptors with 11C-raclopride and 18F-N-methylspiroperidol. Psychiatry Research. 1996;67(1):11-16
  48. 48. Vernaleken I, Weibrich C, Siessmeier T, et al. Asymmetry in dopamine D2/3 receptors of caudate nucleus is lost with age. NeuroImage. 2007;34(3):870-878
  49. 49. Wong D, Wagner H Jr, Tune L, et al. Positron emission tomography reveals elevated D2 dopamine receptors in drug-naive schizophrenics. Science. 1986;234(4783):1558-1563
  50. 50. Farde L, Wiesel F, Stone-Elander S, et al. D2 dopamine receptors in neuroleptic-naive schizophrenic patients. A positron emission tomography study with [11C]raclopride. Archives of General Psychiatry. 1990;47:213-219
  51. 51. Buchsbaum M, Christian B, Lehrer D, et al. D2/D3 dopamine receptor binding with [18F]fallypride in thalamus and cortex of patients with schizophrenia. Schizophrenia Research. 2006;85(1-3):232-244
  52. 52. Talvik M, Nordstrom A, Olsson H, Halldin C, Farde L. Decreased thalamic D2/D3 receptor binding in drug-naive patients with schizophrenia: A PET study with [11C]FLB457. The International Journal of Neuropsychopharmacology. 2003;6(04):361-370
  53. 53. Yasuno F, Suhara T, Okubo Y, et al. Low dopamine D2 receptor binding in subregions of the thalamus in schizophrenia. The American Journal of Psychiatry. 2004;161(6):1016-1022
  54. 54. Kaasinen V, Nagren K, Hietala J, et al. Extrastriatal dopamine D2 and D3 receptors in early and advanced Parkinson's disease. Neurology. 2000;54(7):1482-1487
  55. 55. Kaasinen V, Aalto S, Nagren K, Hietala J, Sonninen P, Rinne J. Extrastriatal dopamine D2 receptors in Parkinson's disease: A longitudinal study. Journal of Neural Transmission. 2003;110(6):591-601
  56. 56. Shreve P, Chiao P, Humes H, Schwaiger M, Gross M. Carbon-11-acetate PET imaging in renal disease. Journal of Nuclear Medicine. 1995;36(9):1595-1601
  57. 57. Yeh S, Liu R, Wu L, Yen S, Chang C, Chen K. 11C-acetate clearance in nasopharyngeal carcinoma. Nuclear Medicine Communications. 1999;20(2):131-134
  58. 58. Jadvar H. Prostate Cancer: PET with 18F-FDG, 18F-or 11C-acetate, and 18F-or 11C-Choline. Journal of Nuclear Medicine. 2011;52(1):81-89
  59. 59. Grassi I, Nanni C, Allegri V, et al. The clinical use of PET with 11C-acetate. American Journal of Nuclear Medicine and Molecular Imaging. 2012;2(1):33-47
  60. 60. Sörensen J, Valind S, Andersson L. Simultaneous quantification of myocardial perfusion, oxidative metabolism, cardiac efficiency and pump function at rest and during supine bicycle exercise using 1-11C-acetate PET--a pilot study. Clinical Physiology and Functional Imaging. 2010;30(4):279-284
  61. 61. Gould KL, Johnson NP, Bateman TM, et al. Anatomic versus physiologic assessment of coronary artery disease: Role of coronary flow reserve, fractional flow reserve, and positron emission tomography imaging in revascularization decision-making. Journal of the American College of Cardiology. 2013;62(18):1639-1653
  62. 62. Phelps M, Hoffman E, Raybaud C. Factors which affect cerebral uptake and retention of 13NH3. Stroke. 1977;8(6):694-702
  63. 63. Walsh W, Fill H, Harper P. Nitrogen-13-labeled ammonia for myocardial imaging. Seminars in Nuclear Medicine. 1977;7(1):59-66
  64. 64. Harper P, Schwartz J, Beck R, et al. Clinical myocardial imaging with nitrogen-13 ammonia. Radiology. 1973;108(3):613-617
  65. 65. Shi X, Zhang X, Yi C, Liu Y. He Q. [13N] Ammonia positron emission tomographic/computed tomographic imaging targeting glutamine synthetase expression in prostate cancer. Molecular Imaging. 2014;13:1-10
  66. 66. Häberle J. Clinical practice: The management of hyperammonemia. European Journal of Pediatrics. 2011;170(1):21-34
  67. 67. Butterworth R. Pathophysiology of brain dysfunction in hyperammonemic syndromes: The many faces of glutamine. Molecular Genetics and Metabolism. 2014;113(1-2):113-117
  68. 68. Hadjihambi A, Khetan V, Jalan R. Pharmacotherapy for hyperammonemia. Expert Opinion on Pharmacotherapy. 2014;15(12):1685-1695
  69. 69. Keiding S, Pavese N. Brain metabolism in patients with hepatic encephalopathy studied by PET and MR. Archives of Biochemistry and Biophysics. 2013;536(2):131-142
  70. 70. Kobayashi M, Kudo T, Tsujikawa T, et al. Shorter examination method for the diagnosis of misery perfusion with count-based oxygen extraction fraction elevation in 15O-gas PET. Journal of Nuclear Medicine. 2008;49(2):242-246
  71. 71. Shidahara M, Watabe H, Kim K, Kudomi N, Ito H, Iida H. Optimal scan time of oxygen-15-labeled gas inhalation autoradiographic method for measurement of cerebral oxygen extraction fraction and cerebral oxygen metabolic rate. Annals of Nuclear Medicine. 2008;22(8):667-675
  72. 72. Iida H, Rhodes C, Araujo L, et al. Noninvasive quantification of regional myocardial metabolic rate for oxygen by use of 15O2 inhalation and positron emission tomography. Theory, error analysis, and application in humans. Circulation. 1996;94(4):792-807
  73. 73. Reutens D, Bittar R, Tochon-Danguy H, Scott A. Clinical applications of [15O]H2O PET activation studies. Clinical Positron Imaging. 1999;2(3):145-152
  74. 74. Ter-Pogossian M, Herscovitch P. Radioactive oxygen-15 in the study of cerebral blood flow, blood volume, and oxygen metabolism. Seminars in Nuclear Medicine. 1985;15(4):377-394
  75. 75. Josephs D, Spicer J, O'Doherty M. Molecular imaging in clinical trials. Targeted Oncology. 2009;4(3):151-168
  76. 76. Boss D, Olmos R, Sinaasappel M, Beijnen J, Schellens J. Application of PET/CT in the development of novel anticancer drugs. The Oncologist. 2008;13(1):25-38
  77. 77. de Molina AR, Rodrı́guez-González AN, Gutiérrez R, et al. Overexpression of choline kinase is a frequent feature in human tumor-derived cell lines and in lung, prostate, and colorectal human cancers. Biochemical and Biophysical Research Communications 2002;296(3):580-583
  78. 78. Ramírez dMA, Penalva V, Lucas L, Lacal J. Regulation of choline kinase activity by Ras proteins involves Ral-GDS and PI3K. Oncogene. 2002;21(6):937-946
  79. 79. DeGrado TR, Coleman RE, Wang S, et al. Synthesis and evaluation of 18F-labeled choline as an oncologic tracer for positron emission tomography: Initial findings in prostate cancer. Cancer Research. 2000;61(1):110-117
  80. 80. DeGrado TR, Baldwin SW, Wang S, et al. Synthesis and evaluation of 18F-labeled choline analogs as oncologic PET tracers. Journal of Nuclear Medicine. 2001;42(12):1805-1814
  81. 81. Huang Y, Tsai C, Wen H, Tzen K, Yen R, Shiue C. High yield one-pot production of [18F]FCH via a modified TRACERlab FxFN module. Applied Radiation and Isotopes. 2017;128:190-198
  82. 82. Ido T, Wan CN, Casella V, et al. Labeled 2-deoxy-D-glucose analogs. 18F-labeled 2-deoxy-2-fluoro-D-glucose, 2-deoxy-2-fluoro-D-mannose and 14C-2-deoxy-2-fluoro-D-glucose. Journal of Labelled Compounds and Radiopharmaceuticals. 1978;14(2):175-183
  83. 83. Shiue CY. Development and design of radiopharmaceuticals: (II) Radiolabelling. In: Paper Presented at: New Radiotracer Development: From Bench to Bedside; 2009/08/15. Taichung, Taiwan: The Taiwanese Society of Medical Cyclotron; 2009
  84. 84. Kitson SL, Cuccurullo V, Ciarmiello A, Salvo D, Mansi L. Clinical applications of positron emission tomography (PET) imaging in medicine: Oncology, brain diseases and cardiology. Current Radiopharmaceuticals. 2009;2(4):224-253
  85. 85. Garnett E, Firnau G, Nahmias C. Dopamine visualized in the basal ganglia of living man. Nature. 1983;305(5930):137-138
  86. 86. Seibyl J, Chen W, Silverman D. 3, 4-dihydroxy-6-[18F]-fluoro-L-phenylalanine positron emission tomography in patients with central motor disorders and in evaluation of brain and other tumors. Seminars in Nuclear Medicine. 2007;37(6):440-450
  87. 87. Isselbacher K. Sugar and amino acid transport by cells in culture--differences between normal and malignant cells. The New England Journal of Medicine. 1972;286(17):929-933
  88. 88. Koopmans K, Neels O, Kema I, et al. Molecular imaging in neuroendocrine tumors: Molecular uptake mechanisms and clinical results. Critical Reviews in Oncology/Hematology. 2009;71(3):199-213
  89. 89. Neels O, Koopmans K, Jager P, et al. Manipulation of [11C]-5-hydroxytryptophan and 6-[18F] fluoro-3, 4-dihydroxy-L-phenylalanine accumulation in neuroendocrine tumor cells. Cancer Research. 2008;68(17):7183-7190
  90. 90. Minn H, Kauhanen S, Seppänen M, Nuutila P. 18F-FDOPA: a multiple-target molecule. Journal of Nuclear Medicine. 2009;50(12):1915-1918
  91. 91. Jager PL, Chirakal R, Marriott CJ, Brouwers AH, Koopmans KP, Gulenchyn KY. 6-L-18F-fluorodihydroxyphenylalanine PET in neuroendocrine tumors: Basic aspects and emerging clinical applications. Journal of Nuclear Medicine. 2008;49(4):573-586
  92. 92. Balogova S, Talbot J-N, Nataf V, et al. 18F-Fluorodihydroxyphenylalanine vs other radiopharmaceuticals for imaging neuroendocrine tumours according to their type. European Journal of Nuclear Medicine and Molecular Imaging. 2013;40(6):943-966
  93. 93. Chondrogiannis S, Grassetto G, Marzola M, et al. 18F-DOPA PET/CT biodistribution consideration in 107 consecutive patients with neuroendocrine tumours. Nuclear Medicine Communications. 2012;33(2):179-184
  94. 94. Rufini V, Treglia G, Montravers F, Giordano A. Diagnostic accuracy of [18F]DOPA PET and PET/CT in patients with neuroendocrine tumors: A meta-analysis. Clinical and Translational Imaging. 2013;1(2):1-12
  95. 95. Rischke H, Benz M, Wild D, et al. Correlation of the genotype of paragangliomas and pheochromocytomas with their metabolic phenotype on 3, 4-dihydroxy-6-18F-fluoro-L-phenylalanin PET. Journal of Nuclear Medicine. 2012;53(9):1352-1358
  96. 96. Gabriel S, Blanchet E, Sebag F, et al. Functional characterization of nonmetastatic paraganglioma and pheochromocytoma by 18F-FDOPA PET: Focus on missed lesions. Clinical Endocrinology. 2013;79(2):170-177
  97. 97. Marzola M, Chondrogiannis S, Grassetto G, et al. 18F-DOPA PET/CT in the evaluation of hereditary SDH-deficiency Paraganglioma-Pheochromocytoma syndromes. Clinical Nuclear Medicine. 2014;39(1):e53-e58
  98. 98. Tuomela J, Forsback S, Haavisto L, et al. Enzyme inhibition of dopamine metabolism alters 6-[18F]FDOPA uptake in orthotopic pancreatic adenocarcinoma. EJNMMI Research. 2013;3:18
  99. 99. Jadvar H. Hepatocellular carcinoma and gastroenteropancreatic neuroendocrine tumors: Potential role of other positron emission tomography radiotracers. Seminars in Nuclear Medicine. 2012;42(4):247-254
  100. 100. Piccardo A, Lopci E, Conte M, et al. Bone and lymph node metastases from Neuroblastoma detected by 18F-DOPA-PET/CT and confirmed by Posttherapy 131I-MIBG but negative on diagnostic 123I-MIBG scan. Clinical Nuclear Medicine. 2014;39(1):e80-e83
  101. 101. Lopci E, Piccardo A, Nanni C, et al. 18F-DOPA PET/CT in neuroblastoma: Comparison of conventional imaging with CT/MR. Clinical Nuclear Medicine. 2012;37(4):e73-e78
  102. 102. Lu MY, Liu YL, Chang HH, et al. Characterization of Neuroblastic tumors using 18F-FDOPA PET. Journal of Nuclear Medicine. 2013;54:1-8
  103. 103. Wester H, Herz M, Weber W, et al. Synthesis and radiopharmacology of O-(2-[18F] fluoroethyl)-L-tyrosine for tumor imaging. Journal of Nuclear Medicine. 1999;40(1):205-212
  104. 104. McConathy J, Yu W, Jarkas N, Seo W, Schuster D, Goodman M. Radiohalogenated nonnatural amino acids as PET and SPECT tumor imaging agents. Medicinal Research Reviews. 2012;32(4):868-905
  105. 105. Langen K, Stoffels G, Filss C, et al. Imaging of amino acid transport in brain tumours: Positron emission tomography with O-(2-[18F] fluoroethyl)-L-tyrosine (FET). Methods. 2017;130:124-134
  106. 106. Pöpperl G, Kreth F, Mehrkens J, et al. FET PET for the evaluation of untreated gliomas: Correlation of FET uptake and uptake kinetics with tumour grading. European Journal of Nuclear Medicine and Molecular Imaging. 2007;34(12):1933-1942
  107. 107. Pauleit D, Floeth F, Tellmann L, et al. Comparison of O-(2-18F-fluoroethyl)-L-tyrosine PET and 3-123I-iodo-alpha-methyl-L-tyrosine SPECT in brain tumors. Journal of Nuclear Medicine. 2004;45(3):374-381
  108. 108. Floeth F, Sabel M, Stoffels G, et al. Prognostic value of 18F-fluoroethyl-L-tyrosine PET and MRI in small nonspecific incidental brain lesions. Journal of Nuclear Medicine. 2008;49(5):730-737
  109. 109. Piroth M, Pinkawa M, Holy R, et al. Prognostic value of early [18F]fluoroethyltyrosine positron emission tomography after radiochemotherapy in glioblastoma multiforme. International Journal of Radiation Oncology, Biology, Physics. 2011;80(1):176-184
  110. 110. Weckesser M, Langen K, Rickert C, et al. O-(2-[18F] fluorethyl)-L-tyrosine PET in the clinical evaluation of primary brain tumours. European Journal of Nuclear Medicine and Molecular Imaging. 2005;32(4):422-429
  111. 111. Grierson J, Shields A. Radiosynthesis of 3′-deoxy-3′-[18F] fluorothymidine:[18F] FLT for imaging of cellular proliferation in vivo. Nuclear Medicine and Biology. 2000;27(2):143-156
  112. 112. Shields A. PET imaging with 18F-FLT and thymidine analogs: Promise and pitfalls. Journal of Nuclear Medicine. 2003;44(9):1432-1434
  113. 113. Kong X, Zhu Q, Vidal P, et al. Comparisons of anti-human immunodeficiency virus activities, cellular transport, and plasma and intracellular pharmacokinetics of 3′-fluoro-3′-deoxythymidine and 3′-azido-3′-deoxythymidine. Antimicrobial Agents and Chemotherapy. 1992;36(4):808-818
  114. 114. Tehrani OS, Shields AF. PET imaging of proliferation with pyrimidines. Journal of Nuclear Medicine. 2013;54(6):903-912
  115. 115. Herrmann K, Buck AK. Proliferation imaging with 18F-Fluorothymidine PET/computed tomography: Physiologic uptake, variants, and pitfalls. PET Clinics. 2014;9(3):331-338
  116. 116. Bollineni V, Kramer G, Jansma E, Liu Y, Oyen W. A systematic review on [18F] FLT-PET uptake as a measure of treatment response in cancer patients. European Journal of Cancer. 2016;55:81-97
  117. 117. Everitt S, Ball D, Hicks R, et al. Differential 18F-FDG and 18F-FLT uptake on serial PET/CT imaging before and during definitive Chemoradiation for non-small cell lung Cancer. Journal of Nuclear Medicine. 2014;55(7):1069-1074
  118. 118. Herrmann K, Wieder HA, Buck AK, et al. Early response assessment using 3′-deoxy-3′-[18F] fluorothymidine-positron emission tomography in high-grade non-Hodgkin's lymphoma. Clinical Cancer Research. 2007;13(12):3552-3558
  119. 119. Thomlinson R, Gray L. The histological structure of some human lung cancers and the possible implications for radiotherapy. British Journal of Cancer. 1955;9(4):539-549
  120. 120. Gray L, Conger A, Ebert M, Hornsey S, Scott O. The concentration of oxygen dissolved in tissues at the time of irradiation as a factor in radiotherapy. The British Journal of Radiology. 1953;26(312):638-648
  121. 121. Lucignani G. PET imaging with hypoxia tracers: A must in radiation therapy. European Journal of Nuclear Medicine and Molecular Imaging. 2008;35(4):838-842
  122. 122. Thomlinson R. Tumour anoxia and the response to radiation. The Scientific Basis of Medicine Annual Reviews. 1965:74-90
  123. 123. Koh W, Rasey J, Evans M, et al. Imaging of hypoxia in human tumors with [F-18]fluoromisonidazole. International Journal of Radiation Oncology, Biology, Physics. 1992;22(1):199-212
  124. 124. Rasey J, Grunbaum Z, Magee S, et al. Characterization of radiolabeled fluoromisonidazole as a probe for hypoxic cells. Radiation Research. 1987;111(2):292-304
  125. 125. Muzi M, Krohn KA. Imaging hypoxia with 18F-Fluoromisonidazole: Challenges in moving to a more complicated analysis. Journal of Nuclear Medicine. 2016;57(4):497-498
  126. 126. Vaupel P, Mayer A. Hypoxia in cancer: Significance and impact on clinical outcome. Cancer Metastasis Reviews. 2007;26(2):225-239
  127. 127. Rajendran J, Krohn K. F18 Fluoromisonidazole for imaging tumor hypoxia: Imaging the microenvironment for personalized Cancer therapy. Seminars in Nuclear Medicine. 2015;45(2):151-162
  128. 128. Rubens R. Bone metastases-the clinical problem. European Journal of Cancer. 1998;34(2):210-213
  129. 129. Gibril F, Doppman J, Reynolds J, et al. Bone metastases in patients with gastrinomas: A prospective study of bone scanning, somatostatin receptor scanning, and magnetic resonance image in their detection, frequency, location, and effect of their detection on management. Journal of Clinical Oncology. 1998;16(3):1040-1053
  130. 130. Blau M, Nagler W, Bender M. Fluorine-18: A new isotope for bone scanning. Journal of Nuclear Medicine. 1962;3:332-334
  131. 131. NSAC. Isotopes subcommittee. In: Isotopes for the Nation's Future a Long Range Plan. Washington DC, USA: Nuclear Science Advisory Committee; 2009
  132. 132. International Atomic Energy Agency. Nuclear Technology Review. Production and Supply of Molybdenum-99 [Annex 7]. http://www.iaea.org/About/Policy/GC/GC54/GC54InfDocuments/English/gc54inf-3-att7_en.pdf
  133. 133. Wong K, Piert M. Dynamic bone imaging with 99mTc-labeled diphosphonates and 18F-NaF: Mechanisms and applications. Journal of Nuclear Medicine. 2013;54(4):590-599
  134. 134. Bridges R, Wiley C, Christian J, Strohm A. An introduction to Na18F bone scintigraphy: Basic principles, advanced imaging concepts, and case examples. Journal of Nuclear Medicine Technology. 2007;35(2):64-76
  135. 135. Grant F, Fahey F, Packard A, Davis R, Alavi A, Treves S. Skeletal PET with 18F-fluoride: Applying new technology to an old tracer. Journal of Nuclear Medicine. 2008;49(1):68-78
  136. 136. Bunchorntavakul C, Chamroonkul N, Chavalitdhamrong D. Bacterial infections in cirrhosis: A critical review and practical guidance. World Journal of Hepatology. 2016;8(6):307-321
  137. 137. Morens D, Folkers G, Fauci A. The challenge of emerging and re-emerging infectious diseases. Nature. 2004;430(6996):242-249
  138. 138. El-Maghraby T, Moustafa H, Pauwels E. Nuclear medicine methods for evaluation of skeletal infection among other diagnostic modalities. The Quarterly Journal of Nuclear Medicine and Molecular Imaging. 2006;50(3):167-192
  139. 139. Chianelli M, Mather S, Martin-Comin J, Signore A. Radiopharmaceuticals for the study of inflammatory processes: A review. Nuclear Medicine Communications. 1997;18(5):437-455
  140. 140. Roivainen A, Jalkanen S, Nanni C. Gallium-labelled peptides for imaging of inflammation. European Journal of Nuclear Medicine and Molecular Imaging. 2012;39(Suppl 1):S68-S77
  141. 141. Silvola JM, Laitinen I, Sipilä HJ, et al. Uptake of 68gallium in atherosclerotic plaques in LDLR−/-ApoB100/100 mice. EJNMMI Research. 2011;1:14
  142. 142. Bernstein L. Mechanisms of therapeutic activity for gallium. Pharmacological Reviews. 1998;50(4):665-682
  143. 143. Menon S, Wagner H Jr, Tsan M. Studies on gallium accumulation in inflammatory lesions: II. Uptake by Staphylococcus aureus: Concise communication. Journal of Nuclear Medicine. 1978;19(1):44-47
  144. 144. Edwards CL, Hayes R. Tumor scanning with 67Ga-citrate. Journal of Nuclear Medicine. 1984;25(6):724-726
  145. 145. Kumar V, Boddeti D. 68Ga-radiopharmaceuticals for PET imaging of infection and inflammation. Recent Results in Cancer Research. 2013;194:189-219
  146. 146. Velikyan I. Prospective of 68Ga-radiopharmaceutical development. Theranostics. 2013;4(1):47-80
  147. 147. Yao J, Hassan M, Phan A, et al. One hundred years after “carcinoid”: Epidemiology of and prognostic factors for neuroendocrine tumors in 35,825 cases in the United States. Journal of Clinical Oncology. 2008;26(18):3063-3072
  148. 148. Reubi J, Waser B, Schaer J, Laissue J. Somatostatin receptor sst1-sst5 expression in normal and neoplastic human tissues using receptor autoradiography with subtype-selective ligands. European Journal of Nuclear Medicine. 2001;28(7):836-846
  149. 149. Henze M, Schuhmacher J, Hipp P, et al. PET imaging of somatostatin receptors using [68GA]DOTA-D-Phe1-Tyr3-octreotide: First results in patients with meningiomas. Journal of Nuclear Medicine. 2001;42(7):1053-1056
  150. 150. John M, Meyerhof W, Richter D, et al. Positive somatostatin receptor scintigraphy correlates with the presence of somatostatin receptor subtype 2. Gut. 1996;38(1):33-39
  151. 151. Eidherr H, Girschele F, Mitterhauser M, Wadsak W. Synthesis of [68Ga] gallium Dota-(Tyr3)-Octreotide acetate ([68Ga]-DOTATOC). In: Scott PJH, Hockley BG, Kilbourn MR, editors. Radiochemical Syntheses: Radiopharmaceuticals for Positron Emission Tomography. Vol. 1. Hoboken: Wiley Inc.; 2012. pp. 321-334
  152. 152. Committe for Medical Products for Humans C. SomaKit TOC edotreotide. London, United Kingdom: European Medicines Agency (EMA); 2017
  153. 153. Velikyan I, Sundin A, Eriksson B, et al. In vivo binding of [68Ga]-DOTATOC to somatostatin receptors in neuroendocrine tumours--impact of peptide mass. Nuclear Medicine and Biology. 2010;37(3):265-275
  154. 154. Zhang H, Moroz M, Serganova I, et al. Imaging expression of the human somatostatin receptor subtype-2 reporter gene with 68Ga-DOTATOC. Journal of Nuclear Medicine. 2011;52(1):123-131
  155. 155. Hofmann M, Maecke H, Börner R, et al. Biokinetics and imaging with the somatostatin receptor PET radioligand 68Ga-DOTATOC: Preliminary data. European Journal of Nuclear Medicine. 2001;28(12):1751-1757
  156. 156. Graham M, Gu X, Ginader T, Breheny P, Sunderland J. 68Ga-DOTATOC imaging of Neuroendocrine tumors: A systematic review and Metaanalysis. Journal of Nuclear Medicine. 2017;58(9):1452-1458
  157. 157. Love W, Romney R, Burch G. A comparison of the distribution of potassium and exchangeable rubidium in the organs of the dog, using rubidium. Circulation Research. 1954;2(2):112-122
  158. 158. Gould K, Goldstein R, Mullani N, et al. Noninvasive assessment of coronary stenoses by myocardial perfusion imaging during pharmacologic coronary vasodilation. VIII. Clinical feasibility of positron cardiac imaging without a cyclotron using generator-produced rubidium-82. Journal of the American College of Cardiology. 1986;7(4):775-789
  159. 159. Kuhl D. Positron emission tomography (PET): Clinical status in the United States in 1987. Journal of Nuclear Medicine. 1988;29:1136-1143
  160. 160. Chatal J-F, Rouzet F, Haddad F, Bourdeau C, Mathieu C, Le Guludec D. Story of Rubidium-82 and advantages for myocardial perfusion PET imaging. Frontiers in Medicine (Lausanne). 2015;2:65

Written By

Ya-Yao Huang

Submitted: 25 February 2018 Reviewed: 31 May 2018 Published: 05 November 2018