Role of FDG PET\CT in the solid renal masses

Abstract

With increasing economic restrictions in healthcare, it is critical for the radiologist to have a clear understanding of what modalities can provide the most accurate information for best therapy choice. Successful management of solid renal tumors requires imaging tests for accurate disease detection, characterization, and treatment monitoring. Technologic developments aim toward the creation of integrated imaging approaches that provide a comprehensive diagnosis with a single visit. PET/CT with 18F-FDG shows metabolically active disease and is widely used for the diagnosis and follow-up of patients with cancer. PET/CT with 18F-FDG is widely used for evaluating tumor metabolism in patients with cancer at various time points during the course of the disease. Aim of this study was to estab¬lish the role of F18-FDG PET/CT in evaluation the patients with solid renal masses. In this work, the anatomy and pathology of solid renal masses was discussed, followed by the principles and techniques of PET/CT. Explanation the mechanisms of FDG uptake and the normal distribution to reduce the pitfalls in the diagnosis. Role of FDG PET/CT was limited role in detection and characterization of primary renal malignancy but this modality accurately detect local and metastatic spread, especially lymph node metastases which can often be falsely negative using the CT size criteria. FDG PET/CT can be particularly helpful for guiding biopsy to the most metabolically active tumor tissue. PET/CT is characterized by high specificity and positive predic¬tive value and can be useful in restaging patients affected by renal carcinoma who underwent partial or radical nephrectomy, the results in the last studies were 82%, 100%, 100%, 66.7% and 86.8%, of the Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of F18-FDG PET/CT were respectively, in diagnosing recurrent disease Early detection of recurrence is clinically important and can improve the prognosis and survival of patients with RCC and will affect the choice of definitive, often curative therapy. CT may underestimate the actual tumor in areas of distorted anatomy after treatment. Despite the documented therapy response, PET/CT has still not been incorporated into the commonly used criteria for evaluating disease response, for example, the response evaluation criteria in solid tumors (RECIST) and is currently used only as an adjunct. Renal AMLs demonstrate very low to low uptake on FDG PET and PET/CT imaging in this study. When a fat-containing tumor in the kidney is found on a CT scan, PET/CT imaging is a useful tool to differentiate a renal AML from a fat-containing malignant tumor including an RCC, liposarcoma, and Wilms tumor. Patients with suspicious renal lymphoma or secondary renal tumor should perform PET/CT imaging for accurately staging or detecting the primary tumor.