The current role of PET/CT in urological malignancies

Introduction In the past decade, there has been significant progress in the field of Nuclear Medicine in the diagnostic evaluation of urological malignancies, mainly because of the technological advance in PET/CT scanners and the increasing variety of positron-emitting radiopharmaceuticals such as 18 F-FDG, 68 Ga-PSMA, 18 F-PSMA, 18 F-sodium fluoride, and others. However, urological imaging with radiotracers is still challenging due to the biodistribution and normal urinary excretion of these tracers, requiring expertise in diagnostic imaging. The purpose of this review was to evaluate the current role of PET/CT imaging in urological malignancies. Methods In this non-systematic review, we will discuss the current role of radiotracers for PET/CT imaging in the prostate, bladder, renal and testicular cancers based on the most recent and relevant publications and current guidelines. Furthermore, we will address imaging techniques to overcome the difficulty in PET/CT urological imaging in order to increase lesion detectability. Results PET/CT images are useful for staging locoregional and distant metastases, restaging/detecting recurrence, evaluating response to therapy, and, in some urological malignancies, may be used as a prognostic indicator. Furthermore, PET/CT images play an increasing role in Theranostics by evaluating patients requiring treatment of bone pain resulting from osteoblastic metastases as well as treatment of metastases from prostate cancer, promoting survival benefits. Conclusion PET/CT imaging has an established role in the diagnosis of some urological malignancies and, in specific clinical indications, is used because of the enormous potential to alter patient management. Besides the established roles of FDG PET/CT, the advances of novel radiotracers for PET/CT imaging in urological malignancies, such as PSMA PET/CT, allows evaluation in the settings of staging, recurrence, response to therapy, and prognosis. Furthermore, PET/CT imaging helps in planning and assessing response to treatment in theranostics. Molecular images identify early changes that conventional anatomical studies cannot, and for this reason, the images performed on PET/CT are becoming increasingly indispensable in specific clinical situations and with precise indications according to the type of urological malignancy.