Androgen deprivation therapy influences the uptake of 11C-choline in patients with recurrent prostate cancer: the preliminary results of a sequential PET/CT study

Purpose The influence of androgen deprivation therapy (ADT) on C-11-choline uptake in patients with prostate cancer (PC) has not yet been clarified. The aim of our study was to investigate this issue by means of sequential C-11-choline positron emission tomography (PET)/CT in patients with recurrent PC. Methods We retrospectively studied 14 recurrent PC patients (mean age 67 years, range 55-82) during follow-up after radical prostatectomy (RP) with rising serum prostate-specific antigen (PSA) levels. All patients had undergone at least two consecutive C-11-choline PET/CT scans: the first C-11-choline PET/CT before commencing ADT and the second C-11-choline PET/CT after 6 months of ADT administration. Results The mean serum PSA level before ADT was 17.0 +/- 44.1 ng/ml. After 6 months of ADT administration the PSA value significantly decreased in comparison to baseline (PSA = 2.4 +/- 3.1 ng/ml, p < .025). Moreover, before starting ADT, 13 of 14 patients had positive C-11-choline PET/CT for metastatic spread, while after 6 months of ADT administration in 9 of 14 patients C-11-choline PET/CT became negative. Conclusion These preliminary results suggest that ADT significantly reduces C-11-choline uptake in androgen-sensitive PC patients.