Detection of prostate cancer with 11C-methionine positron emission tomography

Purpose: We studied the detection of primary prostate cancer with positron emission tomography (PET) using C-11-labeled methionine (MET) in patients with increased prostate specific antigen (PSA) levels and repeatedly negative biopsies. Materials and Methods: A total of 20 consecutive patients with increased serum PSA and negative repeat biopsies were included in the study. Patient age ranged from 52 to 75 years (average 65). PSA levels ranged from 3.49 to 28.6 ng/ml (average 9.36). Dynamic PET images were obtained from the prostate region using C-11-labeled MET. Suspicious accumulations of the tracer were anatomically localized using magnetic resonance images and were used as guidance during the next biopsy. Results: PET was positive in 15 (75%) patients, in 7 of whom (46.7%) the next repeat biopsy verified carcinoma. The overall detection rate was 35% (7 of 20) and 46.7% (7 of 15) in the whole group and in the positive PET group, respectively. All 5 of 5 patients with negative MET PET had negative biopsies. Conclusions: MET PET of the prostate with short dynamic scanning and multicore biopsy is a useful method to ensure a high detection rate of prostate cancer in patients with increased PSA and repeat negative biopsies.