Dose volume effects on gastrointestinal complications in patients receiving postoperative pelvic intensity modulated radiotherapy for early stage cervical cancer

Purpose of investigation: To identify the relationship between dose volume histograms (DVHs) and gastrointestinal (GI) symptoms in cervical cancer patients receiving postoperative pelvic intensity modulated radiotherapy (IMRT). Materials and Methods: Women (n = 140) receiving postoperative IMRT, with or without chemotherapy, were retrospectively analyzed. The GI toxicity severities during and after radiotherapy were evaluated using questionnaires. DVHs of the small bowel, large bowel, and rectum were analyzed using a dose of 5-45 Gy at 5 Gy intervals (V5-V45). Results: Overall, 106 patients (75.7%) received chemotherapy (180-240 mg of paclitaxel on day 1, and 100 mg of nedaplatin on day 1 or 30 mg on days 1, 2, and 3). During median follow-up of 24 months (range, 15-34 months), grade 2-3 acute and chronic GI toxicities were observed in 70 (50.0%) and 15(10.7%) patients, respectively. In the univariate analysis, grade 2-3 acute GI toxicity patients had significantly larger values of small bowel DVHs (V5-V25, p < 0.05). Grade 2-3 acute GI toxicity patients had a higher education level (p = 0.005). Conclusion: Patients undergoing postoperative pelvic IMRT with a larger value of small bowel DVH may be at risk of developing higher-grade acute GI complications.