Background: To evaluate the efficacy of 11C-choline PET/CT (CHO-PET/CT) based
helical tomotherapy (HTT) as a therapeutic approach for bone metastases in recurrent prostate
cancer (PCa) patients.
Methods: This retrospective study includes 20 PCa patients (median age: 67; range: 51-80 years)
presenting biochemical relapse after primary treatment who underwent CHO-PET/CT based HTT
on positive bone metastases from December 2007 to June 2014. The effectiveness of HTT has
been assessed with biochemical response at 3/6/12 months, biochemical relapse free survival
(bRFS) and overall survival (OS) at 2 years. Toxicity has also been considered and assessed according
to Common Terminology Criteria for Adverse Events (CTCAE).
Results: All patients presented a relapse at the time of CHO-PET/CT at bone level. In addition
15/20 (75%) also at lymph nodes (LNs) level (total lesions= 54). All patients underwent HTT on
bone metastases and 19/20 concomitantly on prostatic bed and LNs. The median follow-up from
CHO-PET/CT was 2 years (range: 1-7 years). At 3 months after the beginning of HTT treatment
complete or partial biochemical response occurred in 79% of patients, at 6 months in 82% and at
12 months in 63% of patients. bRFS and OS at 2 years were 50% and 55% of patients, respectively.
Patients presented mostly grade 1 or 2 toxicity according to CTCAE. The only grade 3 late
toxicity has been observed in one patient.
Conclusion: CHO-PET/CT based HTT is a suitable therapeutic approach in patients with recurrent
PCa presenting bone metastases with a medium-low toxicity.