Intensity-modulated radiotherapy of prostate cancer with simultaneous integrated boost after molecular imaging with 18F-choline-PET/CT

To analyze clinical results and quality of life of patients with localized prostate cancer after irradiation of the prostate with an 18F-choline-PET/CT-based simultaneous integrated boost (SIB) in comparison to a control group without SIB. A total of 134 patients underwent intensity-modulated radiotherapy from 2007-2010. All patients received a total dose of 76Gy with 2Gy fractions to the prostate; 67 patients received an additional SIB of 80Gy. The median follow-up was 65 months. Quality of life was evaluated with the EPIC (Expanded Prostate Cancer Index Composite) questionnaire. Baseline characteristics were similar in both groups (prostate-specific antigen 11ng/ml vs. 8ng/ml, p= 0.20, Gleason score < 6 in 36% vs. 46%, p= 0.22, with vs. without SIB). No prostate cancer-related death was observed. No significant difference of quality of life scores was found. The largest difference after 5-6 years in comparison to baseline was reported for sexual bother (mean 15 vs. 17 points with vs. without SIB). Mean urinary scores did not decrease. Bowel bother scores changes were larger in the SIB group (mean 5 vs. 2 points, dependent on SIB volume), with increased bowel problems (15 vs. 2% big/moderate problem with bowel movements, p= 0.03). However, a trend towards higher efficacy with SIB resulted (biochemical recurrence-free survival of 92% vs. 85%, p= 0.17). The first long-term analysis of patients treated with SIB based on molecular imaging with 18-F-choline-PET/CT showed an excellent biochemical recurrence-free survival, but a larger percentage of bowel problems in comparison to the control group.