MP62-17 DIAGNOSTIC EFFICACY OF 18 F-RHPSMA-7.3 IMAGING FOR N-STAGING PATIENTS WITH HIGH-RISK PROSTATE CANCER

RESULTS: A total of 113 patients were included, of which 17 patients (15%) harboured lymph node metastases on pathological evaluation (N1).The sensitivity, specificity, positive predictive value and negative predictive value of 18 F-PSMA PET/CT for N1 was 41% (CI 19%-66%), 94% (CI 86%-97%), 54% (CI 26%-79%) and 90% (CI 81%-94%), respectively.Interobserver agreement on imaging N-stage was 95% (CI 90-98%).Additionally, the detection of locally advanced tumour growth (T-stage 3-4) was evaluated, for which 18 F-PSMA PET/CT had a sensitivity, specificity, PPV and NPV of 44% (CI 32-57%), 94% (CI 83%-98%), 90% (CI 72%-97%) and 59% (CI 47-69%).CONCLUSIONS: 18 F-PSMA PET/CT has a high specificity (94%), yet a limited sensitivity (41%) for the detection of pelvic lymph node metastases in patients with primary PCa.Promising specificity for detection of locally-advanced tumour stages with 18 F-PSMA PET/CT was observed.