PSMA PET Registry (18F-DCFPyL)

Overview

The purpose of the Princess Margaret Cancer Centre PSMA registry is to assess the contribution of 18F-DCFPyL (PSMA) PET imaging (PET/MR or PET/CT) to the management of patients with prostate cancer (PCa). Background: Currently, patients with intermediate or high risk prostate cancer are staged with CT abdomen and pelvis and bone scan to assess for distant metastases. Patients with biochemical recurrence after primary therapy are restaged in a similar manner. Locally, multiparametric MR of the prostate or prostate bed may also be obtained in select cases. Patients recruited for this registry will be staged/ restaged with PSMA PET (PET/CT or PET/MR) to determine whether this imaging strategy results in more accurate detection of metastatic disease (for patients undergoing primary staging) or detection of local recurrence or distant disease (for patients undergoing restaging). Choice of imaging method (PET/CT or PET/MR) will be made by one of the study PIs, based on clinical judgement taking into account the specific exam indication, prior recent imaging, and suitability for MR imaging. Study design: This is a single arm study to assess the contribution of PSMA PET imaging (PET/MR or PET/CT) to the management of patients with prostate cancer (PCa). In this prospective trial, the investigators will recruit 200 men whom will undergo PET imaging using an integrated PET/CT scanner or with an integrated PET/MR. Patients will receive standard treatment for PCa according to UHN/PMH urology oncology site policies. Treatment outcome including clinical response, blood work including serial serum PSA, and follow-up imaging if performed up to 5 years will be recorded.

Prostate cancer (PCa) is the most common cancer among Canadian men. Men diagnosed with localized PCa are placed in low, intermediate and high-risk groups, using the prognostic variables including pathologic Gleason score, T-stage and serum prostate specific antigen (PSA). These risk groups correlate with biochemical failure-free survival and prostate cancer specific mortality \[1\]. Although PCa is prevalent, the risk of clinical or fatal PCa in a 50 year old man is estimated at only 10% and 3%, respectively \[2\]. Currently, over 2/3 of men diagnosed with PCa are diagnosed with organ confined, low risk disease (PSA \< 10 ng/ml, Gleason score (=GS) 3+3, cT1c) \[3\]. Management is dependent on tumor grade, size and stage and clinical parameters (e.g. life expectancy) and may range from active surveillance to radical therapy including definitive whole gland treatment (radical prostatectomy (RP), or radiotherapy). Although radical whole gland therapy is effective from an oncological standpoint, it may be associated with significant side effects. A more conservative approach in select patients may be enrollment in an active surveillance program. The concept behind this approach is that small volume, low grade PCa may have an indolent course and may not progress to biological significance in the absence of treatment in the patient's lifetime. Rationale for this study is to determine in a prospective cohort of patients with unfavorable intermediate-risk or high-risk PCa, whether PSMA PET improves the detection of lymph node and distant metastases as compared to conventional imaging strategies (CT abdomen and bone scintigraphy). To determine the rate of change in planned management after adding information from PSMA PET in patients with PCa being staged prior to primary therapy or restaged after primary therapy. The central hypothesis behind the Princess Margaret Cancer Centre PSMA PET registry is that in patients with PCa, PSMA PET will enable more accurate staging and restaging, and improve prognostic stratification as compared to conventional workup. Furthermore, the investigators hypothesize that the addition of PSMA PET to the workup of these patients will change the planned management in a significant proportion of patients. Primary Objective: To determine in a prospective cohort of patients with unfavorable intermediate-risk or high-risk PCa, whether PSMA PET improves the detection of lymph node and distant metastases as compared to conventional imaging strategies (CT abdomen and bone scintigraphy). To determine the rate of change in planned management after adding information from PSMA PET in patients with PCa being staged prior to primary therapy or restaged after primary therapy. Secondary Objective: To determine the clinical outcome and rate of biochemical control after therapy. For this purpose, information from clinical notes of routine clinical visits, results of blood tests (such as serum PSA) and follow-up imaging, if performed, will be collected for up to 5 years.