Radiotherapy of localised prostate cancer. Analysis of late treatment complications. A prospective study

Purpose: To describe the late side-effects of radical radiotherapy of prostatic carcinoma and to analyse how pretreatment and treatment-related factors contribute to the toxicity. Materials and methods: 184 patients have regularly been followed after terminated radical external beam radiotherapy treatment (70 Gy) for a mean of 46 (range 24-96) months. For registration of toxicity a modified RTOG scale was used. The Cox regression model was used for multivariate analysis. Results: 37% of the patients had no late side-effects at all. Mild complications were reported by 53%, mainly gastrointestinal (42%) and urogenital (23%). A persistent improvement of the mild toxicity was seen in nearly half of the patients with gastrointestinal or nocturnal frequency side-effects. Only 16 (9%) patients had moderate or severe complications. The multivariate analysis revealed that the risk of posttreatment complications was strongly correlated to pretreatment presence of symptoms from the organs at risk. Posttreatment complications presenting first 3 years after irradiation were rare. Conclusions: Radical external beam radiotherapy (70 Gy) can be given with a low risk of severe complications. It appears reasonable to assume that the risk can be further reduced by excluding patients with gastrointestinal and urinary tract disease or symptoms. (C) 1997 Elsevier Science Ireland Ltd.