Prospective evaluation of urinary and intestinal side effects after BeamCath ® stereotactic dose-escalated radiotherapy of prostate cancer

Abstract

Background: New data suggest that a higher radiation dose will improve outcome in treatment of localized prostate cancer. External beam radiotherapy (EBRT) may on the other hand induce disturbances in the patient's urinary and intestinal function. Since 1997, 195 patients have been treated with a stereotactic boost of 4–8 Gy added to conventional 70 Gy EBRT. Late side effects were prospectively evaluated 3 years after dose-escalated EBRT. Methods: Urinary and intestinal problems were prospectively evaluated with a validated self-assessment questionnaire, the Prostate Cancer Symptom Scale (PCSS). Two hundred and eighty-seven patients completed the questionnaire at the 1 year follow-up, and 153 at 3 years after treatment. Pre-treatment mean age was 66 years. One hundred and sixty-eight patients were treated with the conformal technique and 195 were treated with the dose-escalated stereotactic BeamCath ® technique. Mean total dose in the conformal group (≤70 Gy) was 66 Gy (60.8–70.4 Gy). The dose-escalated group consists of three dose levels, 74 Gy ( n=68), 76 Gy ( n=74), and 78 Gy ( n=53). Results: Analyzing the whole population 3 years after treatment, urgency and starting problems decreased in comparison to pre-treatment. A minor increase in urinary incontinence was reported 3 years after treatment in comparison to pre-treatment. No increases in other urinary symptoms were reported. Intestinal symptoms were slightly increased during the follow-up period in comparison to pre-treatment. Dose escalation with stereotactic EBRT (74–78 Gy) did not increase gastrointestinal or genitourinary late side effects at 1 year or 3 years in comparison to doses ≤70 Gy. Conclusions: The stereotactic BeamCath ® EBRT technique facilitates safe dose escalation of patients with prostate cancer.