ANDROGEN DEPRIVATION THERAPY INFLUENCES THE UPTAKE OF 11C-CHOLINE IN PATIENTS WITH RECURRENT PCA: RESULTS OF A SEQUENTIAL PET/CT STUDY IN 22 PATIENTS

PURPOSE: The influence of androgen deprivation therapy (ADT) on (11)C-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 (11)C-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 (11)C-choline PET/CT scans: the first (11)C-choline PET/CT before commencing ADT and the second (11)C-choline PET/CT after 6 months of ADT administration. RESULTS: The mean serum PSA level before ADT was 17.0 \ub1 44.1 ng/ml. After 6 months of ADT administration the PSA value significantly decreased in comparison to baseline (PSA = 2.4 \ub1 3.1 ng/ml, p < .025). Moreover, before starting ADT, 13 of 14 patients had positive (11)C-choline PET/CT for metastatic spread, while after 6 months of ADT administration in 9 of 14 patients (11)C-choline PET/CT became negative. CONCLUSION: These preliminary results suggest that ADT significantly reduces (11)C-choline uptake in androgen-sensitive PC patients