2039 IMPACT OF 11C-CHOLINE PET/CT SCAN ON DETECTION OF RECURRENT PROSTATE CANCER IN MEN WITH BIOCHEMICAL RECURRENCE FOLLOWING FAILED INITIAL TREATMENT

Abstract

INTRODUCTION AND OBJECTIVES: Distinguishing localized recurrence from systemic recurrence represents an important step in optimizing prostate cancer treatment following primary treatment failure. We examined the performance of C-choline PET/CT scan for its ability to delineate prostate cancer distribution and extent after failed definitive therapy. METHODS: Retrospective review was performed of all prostate cancer patients who underwent evaluation using C-choline PET/CT scan from 9/2007 to 11/2010 at Mayo Clinic. Analysis was restricted to patients with biochemical recurrence following failed primary prostate cancer treatment. Statistical analysis was performed to determine the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: During the study period 176 patients with biochemical recurrence after primary treatment failure underwent C-choline PET/CT scan. In this setting C-choline PET scanning yielded a sensitivity, specificity, PPV, and NPV of 93, 76, 91, and 81%, respectively. 56 of 166 (32%) PET scans performed were deemed clinically “useful” as defined by their ability to detect treatable lesions, not identified using conventional imaging, thereby triggering changes in clinical management. The PSA cut-off at which PET scan was most likely to be positive was 2.0ng/ml. On multivariate analysis, PSA at the time of PET scan (HR 1.37, 95% CI: 1.0-1.01, p 0.04) and clinical stage (HR 5.19, 95% CI: 1.72-15.68, p 0.0035) were significant predictors of a positive C-choline PET/CT scan. CONCLUSIONS: C-choline PET/CT scan performs well in men with biochemical recurrence following primary treatment failure. The optimal value for lesion detection is approximately 2.0mg/ml. We find that C-choline PET/CT substantially enhances the rate of prostate cancer lesion detection by approximately 32% beyond what can be garnered using conventional imaging technologies and has significant potential to impact treatment of men with recurrent prostate cancer.