ABSTRACT
The intent of this review is to describe the current state of radioimmunoscintigraphy (RIS) as applied to imaging prostate cancer in order to enable urologists and oncologists to identify cases where it can be used to facilitate staging of their patients’ disease. The focus of study is fusion of functional images of prostate cancer and metastases on anatomically detailed images obtained from computed tomography (CT) or magnetic resonance imaging (MRI) in order to facilitate optimally delineating the extent of disease. The functional modalities discussed are positron emission tomography (PET) and single photon emission computed tomography (SPECT). In its most widely used oncologic application, PET is based on identifying the enhanced metabolic activity that generally accompanies carcinogenesis by using 2-[F-18]fluoro-2-deoxy-Dglucose (FDG) as the marker of metabolic activity. In contrast, SPECT imaging of prostate cancer is based on localizing the uptake of the monoclonal antibody (MAB) capromab pendetide, which targets prostate-specific membrane antigen (PSMA), an antigen that is strongly associated with prostate cancer. Functional images of FDG or capromab pendetide uptake superimposed on CT or MRI images provide a map of prostate cancer localization both within and external to the prostate. This map greatly facilitates staging the cancer, and thereby permits optimum treatment of the disease. The same map can also be used to guide radiation therapy, lymphadenectomy, or biopsy. The key to the success of this fused imaging technology is optimizing each step of the imaging process from patient preparation to image acquisition, processing, fusing, and interpretation. A
range of illustrative case reports are presented to demonstrate various aspects of applying RIS to characterize prostate cancer and sites of its metastasis.
