Clinical impact of 11C-Choline PET/CT in recurrent prostate cancer patients after radical therapy: Which is the real impact on treatment decisions?

Objectives To investigate the clinical impact of 11C-Choline-PET/CT on treatment management decision in recurrent prostate cancer (rPC) patients after primary therapy.

Methods 150 rPC patients (pts) with rising PSA values (mean=4.3 ng/mL; range=0.2-39.4; SD±5.5) after primary therapies were retrospectively enrolled. Intended treatment before PET/CT was salvage radiotherapy of the prostatic bed in 95/150 and palliative androgen deprivation therapy (ADT) in 55/150 patients. Clinical impact of PET/CT was rated as major (change of therapeutic approach), minor (same treatment, but modified therapeutic strategy) and none. Positive PET/CT findings were validated by histology (17.3%) or clinical follow-up (>12 months) and correlative imaging (82.7%). Multivariate analysis (including PSA, PSA kinetics, on-going ADT, Gleason score, TNM, age and time to relapse) was performed.

Results Implemented changes of therapy after PET/CT were found in 46.7 % of pts. A major clinical impact was observed in 18.0% (27/150 pts) and a minor clinical impact in 28.7% (43/150 pts). PET/CT was positive in 109/150 pts (72.7%) detecting local relapse (prostate bed and/or iliac LNs and/or para-rectal LNs) in 64/150 patients (42.7%). Distant relapse (para-aortic and/or retroperitoneal LNs and/or bone lesions) was reported in 31/150 pts (20.7%), local and distant relapse in 14/150 (9.3%). A significant statistical difference was observed for PSA and PSA kinetics among PET positive and PET negative pts (p<0.05). At multivariate statistical analysis PSA, PSA doubling-time and on-going ADT were related to a positive scan (p<0.05)

Conclusions 11C-Choline-PET/CT had an important impact on therapeutic management in rPC by leading to major implemented clinical changes in 18.0% of patients.