Acute and Late Genitourinary Toxicity after 72 Gy of Conventionally Fractionated Conformal Radiotherapy for Localised...

Our aim was to estimate the incidence of acute and late genitourinary toxicity in patients treated with three-dimensional conformal radiotherapy (3DCRT) for localised prostate cancer and to estimate the possible influence of individual and clinical characteristics.

Between September 2009 and September 2013, 225 patients with localised prostate cancer were treated with 3DCRT. Ninety-four patients with an estimated risk of lymph node involvement ≤15%, according to the Roach formula, were evaluated in this study. All patients received a total dose of 72 Gy in 36 fractions. Acute and late genitourinary toxicity were graded according to the European Organization for Research and Treatment of Cancer radiation morbidity scoring scale. Characteristics such as age, smoking status, previous abdominal or pelvic surgery (PAPS), diabetes mellitus and the use of diuretics were analysed as possible predictive factors of toxicity. The median follow-up was 27 months.

Grade ≥2 acute toxicity during 3DCRT developed in 25 of 94 patients (26.5%). Predictive factors of acute genitourinary toxicity grade ≥2 in the multivariate logistic regression analysis (MVA) were current smoking status (P = 0.003), PAPS (P = 0.012) and the use of diuretics (P = 0.017). The 2 and 3 year cumulative risk of late genitourinary toxicity grade ≥1 was 25.3% and 30.2%, respectively. In the MVA, acute genitourinary toxicity was significantly associated with late genitourinary toxicity (P = 0.024).

Current smoking status, PAPS and the use of diuretics have a significant effect on the occurrence of acute genitourinary toxicity grade ≥2. The occurrence of any grade of acute genitourinary toxicity has a significant influence on the development of any grade of late genitourinary toxicity.