A prospective observational study with dose volume parameters predicting rectosigmoidoscopic findings and late rectosigmoid bleeding in patients with uterine cervical cancer treated by definitive radiotherapy

摘要

Purpose We assessed the value of dose-volumetric parameters predicting rectosigmoid mucosal changes (RMC) and late rectosigmoid complications (LRC). Methods Between January 2004 and February 2006, 77 patients with stage IB-IIIB cervical cancer underwent external beam radiotherapy and computed tomography (CT)-based intracavitary irradiation. Total dose to the rectal point and several dose-volumetric parameters for rectosigmoid colon (D20cc, D15cc, D10cc, D5cc, D2cc, D1cc, and D0.1cc , defined as the minimal doses received by the highest irradiated volumes of 20, 15, 10, 5, 2, 1, and 0.1 cc, respectively), were calculated using the equivalent dose in 2 Gy fractions (α/β?=?3, Gy3). The RMC and LRC were graded by rectosigmoidoscopy and Radiation Therapy Oncology Group criteria every 6 months, respectively. Results Of 77 patients, 27 (35.1%) patients developed RMC?≥?score 3 and 22 (28.6 %) patients developed LRC?≥?grade 2. There was a positive correlation between RMC score and LRC grade (r?=?0.728, p?