Cancer is a disease that starts in a localized organ or tissue and then grows out of control. Breast cancer is an important health problem as in the Western world; it is the second most frequent cause of cancer death in women (after lung cancer). The incidence rate, however, rises dramatically over the age of 50 years. This is may be due to several risk factors, such as family history, genetics, early menstruation, late menopause, and other factors, that have not yet been identified. The problems of breast diseases have prompted global governments to put constant efforts to increase patient's recovery level against this disease. Early and accurate detection with mass screening programs helps improves a woman's chances for successful treatment. It also minimizes pain, suffering, and anxiety that surround patients and their families. The current and the most cost-effective technique used for screening and diagnosis of breast cancer is X-ray mammography. It is the state-of-the-art for earlier detection to improve both prognosis and survival rate. This is may be due to its good availability, high sensitivity, and relatively low cost/patient. The goal of this chapter is to introduce the problems caused by breast cancer. Starting with an overview of the requirement for breast tumor imaging and the diagnostic techniques used for breast cancer assessment are briefly described, highlighting the advantages and disadvantages of each technique. In addition, the problems associated with a relatively new functional breast imaging technique namely scintimammography were introduced and discussed. The intention that the chapter provide the reader with sufficient background on the available diagnostic techniques of breast tumor imaging approach, as well as an overview of the literature.
Part of the book: Breast Imaging
Breast cancer is a life-threatening disease and considered one of the most common forms of cancer among women worldwide. Early and accurate detection with mass screening programmes helps improve a woman’s chances for successful treatment. The current and the most effective technique used for screening and diagnosis of breast cancer is the X-ray mammography. The photon transport detection of such technique is mostly based on a forward scattering mechanism as well as makes use of attenuation and penetration coefficients. The painful compression and the double X-ray exposure of both patients’ breasts carried out during the imaging process remain unavoidable. In addition, the conventional 2D mammography has two major limitations: sensitivity in detecting breast cancers (~ <80%) and the high recall rate (~10%). It suffers from certain limitations, most important of which is tissue overlap and false diagnoses arising thereof. To overcome this and as an alternative, a new 3D imaging method for breast cancer screening and diagnosis, namely, tomosynthesis, has recently been used. In such method, a limited number of low-dose 2D projection images of a patient are used to reconstruct the 3D tissue information. Tomosynthesis systems incorporate an X-ray source that moves over a certain angle to acquire images. This tube motion is a major limitation because it degrades image quality, increases the scan time and causes prolonged patient discomfort. Therefore, the goal of this work was to overcome all of the above limitations by developing an innovative proof of concept for painless 3D X-ray mammography to be hopefully used as a screening and as diagnostic methods for breast cancer detection by utilizing the scattered X-ray photon information. Most imaging modalities required a wide spectrum of capabilities, which span biomedical sciences, physical sciences and clinical medicine; thus, the ongoing methodology aims to establish a collaborative cross-disciplinary research engaging together with scientists in universities and clinicians in hospitals. Consequently, we hope that this work provides the potential to score some successes in clinical imaging science. In order to do this and since it is generally not possible or feasible to use real components to build and optimize a system repeatedly, a Monte Carlo simulation was used. The first phase focused on realistic computer simulation of the proposed imaging system to find the optimum setup as well as to aid in the analysis of the effect of various factors on the system performance. Thus, the main focus was on 3D mammography imaging simulation setup. Five main steps have been carefully checked and successfully produced: (a) the production of X-ray radiation or source after careful and detailed physics check. This includes the interaction between the X-ray photons and the object (the 3D breast phantom) that is used on scan as well as the detector system and its associated electronics modelled. (b) Next is the realistic modelling of anthropomorphic breast phantoms to check if the effectiveness of prediction of the simulation is successfully achieved. A computer simulation model is developed to estimate the radiation dose to the breast that would be incurred using mammography. Mono-energetic normalized glandular dose coefficients, DgN(E), were computed for energies 11–120 keV using breast phantoms of various sizes and compositions.
Part of the book: Breast Imaging