Radiotherapy Research Today is a free monthly online journal that collates and summarizes the latest research about Radiotherapy, including details on cancer treatment, side effects. | ||||||||
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Predictors for chronic urinary toxicity after the treatment of prostate cancer with adaptive three-dimensional conformal radiotherapy: dose-volume analysis of a phase II dose-escalation study.Harsolia A, Vargas C, Yan D, Brabbins D, Lockman D, Liang J, Gustafson G, Vicini F, Martinez A, Kestin LL Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI 48073, USA. PURPOSE: To identify factors predictive for chronic urinary toxicity secondary to high-dose adaptive three-dimensional conformal radiation. METHODS AND MATERIALS: From 1999 to 2002, 331 consecutive patients with clinical Stage II-III prostate cancer were prospectively treated (median dose, 75.6 Gy). The bladder was contoured, and the bladder wall was defined as the outer 3 mm of the bladder solid volume. Toxicity was quantified according to the National Cancer Institute Common Toxicity Criteria 2.0. Median follow-up was 1.6 years. RESULTS: The 3-year rates of Grade > or =2 and Grade 3 chronic urinary toxicity were 17.0% and 3.6%, respectively. Prostate volume, confidence-limited patient-specific planning target volume, bladder wall volume, and acute urinary toxicity were all found to be accurate predictors for chronic urinary toxicity. The volume of bladder wall receiving > or =30 Gy (V30) and > or =82 Gy (V82), along with prostate volume, were all clinically useful predictors of Grade > or =2 and Grade 3 chronic urinary toxicity and chronic urinary retention. Both Grade > or =2 (p = 0.001) and Grade 3 (p = 0.03) acute urinary toxicity were predictive for the development of Grade > or =2 (p = 0.001, p = 0.03) and Grade 3 (p = 0.05, p < 0.001) chronic urinary toxicity. On Cox multivariate analysis the development of acute toxicity was independently predictive for the development of both Grade > or =2 and Grade 3 chronic urinary toxicity. CONCLUSIONS: Acute urinary toxicity and bladder wall dose-volume endpoints are strong predictors for the development of subsequent chronic urinary toxicity. Our recommendation is to attempt to limit the bladder wall V30 to <30 cm(3) and the V82 to <7 cm(3) when possible. If bladder wall information is not available, bladder solid V30 and V82 may be used. Published 30 October 2007 in Int J Radiat Oncol Biol Phys, 69(4): 1100-9.
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