Bowel complications after radiotherapy for carcinoma of the prostate: the volume effect

Late radiation-induced bowel complications were studied in 218 patients treated for localized carcinoma of the prostate by radical radiotherapy at the Prince of Wales Hospital between 1980 and 1986. Mild to moderate toxicity was seen in 38 cases, and severe toxicity requiring surgery occurred in 3 patients. The total actuarial complication rate (by 5 years) for all grades was 24% and for severe complications was 1.8%. Significant patient-related risk factors were older age at the time of radiotherapy (p = 0.035) and a previous history of abdominal operations (p = 0.028). Among treatment-related risk factors only inclusion of the whole pelvis in the irradiated volume had a significant association with this complication (p = 0.015). The risk of bowel complications was not related to the total radiation dose or to the use of interstitial implants as employed in this series.