18-Fluoro-choline PET/CT in prostate cancer: Which acquisition protocol?

Objective. - To define an optimal acquisition protocol for 18-fluoro-choline (18-FCH) PET/CT in prostate cancer (PCa), due to lack of standard guidelines from the nuclear medicine associations. Materials and methods. - Twenty-four PCa patients were included and have had an 18-FCH three phase PET/CT: dynamic pelvic study during the first 10 minutes post-tracer injection (PI), static base of skull-mid thigh at 20 and 60 minutes PI. A quantitative analysis of tracer activity was performed on target tissue and healthy ones at 20 and 60 minutes by drawing regions of interest and measuring the SUV_max. A statistical analysis was performed on the SUV_max values of the lesions obtained at 20 and 60 minutes PI in order to find a difference between the results and also between the lesions and healthy tissue. Results. - Our study showed no significant difference in the SUV_max values measured at target tissue between 20 and 60 minutes (P = 0.98). However, there is a significant difference between target and healthy tissue (P_prostate = 0.006 at 20 and 60 minutes, P_lymph node = 0.016 at 20 minutes 0.0047 at 60 minutes). Our sample group was too small to obtain a statistical difference between healthy bone and target lesion. Conclusion. - Our study showed no significant differences between the results of 18-FCH PET/CT obtained at 20 and 60 minutes PI in PCa. So we propose a pelvic dynamic acquisition during the first 10 minutes PI, then an acquisition PET/CT from the cranial vault-mid thigh at 20 minutes PI. (authors)