Influence of C-choline PET/CT on radiotherapy planning in prostate cancer

Abstract

Aim

To evaluate the influence of ¹¹C-choline PET/CT on radiotherapy planning in prostate cancer patients.

Background

Precise information on the extension of prostate cancer is crucial for the choice of an appropriate therapeutic strategy.

¹¹C-choline positron emission tomography (¹¹C-choline PET/CT) has two roles in radiation oncology (RT): (1) patient selection for treatment and (2) target volume selection and delineation.

In conjunction with high-accuracy techniques, it might offer an opportunity of dose escalation and better tumour control while sparing healthy tissues.

Materials and methods

We carried out a retrospective study in order to analyse RT planning modification based on ¹¹C-choline PET/CT in 16 prostate cancer patients. Patients were treated with hypofractionated step-and-shoot Intensity Modulated Radiotherapy (IMRT), or Volumetric Modulated Arc Therapy (VMAT), and a daily cone-beam CT for Image Guided Radiation Therapy (IGRT). All patients underwent a ¹¹C-choline-PET/CT scan prior to radiotherapy.

Results

In 37.5% of cases, a re-delineation and new dose prescription occurred. Data show good preliminary clinical results in terms of biochemical control and toxicity. No gastrointestinal (GI)/genitourinary (GU) grade III toxicities were observed after a median follow-up of 9.5 months.

Conclusions

In our experience, concerning the treatment of prostate cancer (PCa), ¹¹C-choline PET/CT may be helpful in radiotherapy planning, either for dose escalation or exclusion of selected sites.