FCH PET/CT in the assessment of recurrent prostate cancer: Correlation with PSA level

1913 Objectives To evaluate the potential of 18F fluoromethylcholine (FCH) PET/CT in the assessment of suspected recurrent prostate cancer in patients with biochemical evidence of recurrence and to correlate its diagnostic accuracy with PSA levels. Methods This study included 240 prostate cancer patients at PSA relapse after initial treatment who had undergone FCH PET/CT for the evaluation of recurrent disease. The mean PSA level was 41.2±319.5 ng/ml. Hormonal treatment(HT) was performed in 151(63%) cases after initial treatment. Imaging was performed on an integrated PET/CT system. Acquisition started 1 minute post intravenous injection of FCH (4Mbq/kg/bw) with dynamic PET images in the pelvic. Static acquisition from thigh to the base of skull was performed 10 min post injection, respectively. The final diagnosis of positive PET lesions was based on histopathological findings or a consensus based on clinical findings, additional imaging modalities and follow-up imaging modalities with a mean time interval of 5.3 months. Results FCH PET/CT was able to correctly detect malignant lesions in 160(66%) patients. The mean PSA level at the time of imaging was 60.3±389.0 ng/ml in patients with positive FCH PET/CT compared to 2.3±3.5 ng/ml in patients with negative FCH PET/CT studies (P=0.06). Although the finding does not reach statistical significance;however, there is a clear trend toward higher PSA levels with positive FCH results. FCH PET/CT were positive in 90.8% of patients with PSA levels ≥4.0 ng/ml while it was 42.9% in patients with PSA levels Conclusions Our data suggest that FCH PET/CT can reliably detect recurrent disease in prostate cancer patients especially in case of PSA level ≥2.5 ng/ml