Title: Risk Factors of Severe Late Complications in Patients with Uterine Cancer Treated with Postoperative Radiotherapy
Abstract: To identify the incidences and the risk factors of severe radiation enterocolitis and/or severe leg edema in patients with uterine cervical cancer or uterine corpus cancer treated with postoperative radiotherapy. The records of 277 patients treated with radical hysterectomy and postoperative pelvic radiotherapy (uterine cervix: 101 patients; uterine corpus: 176 patients) were retrospectively reviewed. Most of the patients were treated with pelvic radiotherapy 5 days per week using daily fractions of 1.8 to 2 Gy. External beam radiotherapy was delivered using a 15 or 18 MV linear accelerator, and the median external beam radiation dose to the pelvis was 50 Gy (range, 10.8-68 Gy). The majority of the patients (85.1%) were treated with a total dose of 50 or 50.4 Gy. Thirty-one patients (11.2%) were treated with the para-aortic nodes in addition to pelvic field. Intracavitary brachytherapy (IB) was added in 17 patients (6.1%) and chemotherapy was supplemented in 38 patients (13.7%). The median duration of follow-up of all 277 patients was 79 months (range, 1 to 240 months). For statistical analyses, the chi-square test and logistic regression analysis were used to investigate the relationship between variables and the occurrence of severe radiation enterocolitis (requiring surgery) and severe leg edema (with secondary dysfunctions). A probability level of 0.05 was chosen for statistical significance. Statistical analysis was performed using the SPSS software package. Thirty patients (10.8%) developed severe radiation enterocolitis and/or severe leg edema. Nineteen patients (6.1%) developed severe radiation enterocolitis with a median latency of 11.6 months, and ileum was the most frequently affected lesion. On multivariate analysis, DM and smoking were independent predictors of severe radiation enterocolitis. Thirteen patients (4.6%) developed severe leg edema with a median latency of 67.2 months. Although the treatment for leg edema was administered, 12 of 13 (92.3%) did not improve the degrees of leg edema. On multivariate analysis, IB use was an independent predictor of severe leg edema. Approximately 10% of patients with uterine cancer treated with postoperative radiotherapy experienced severe radiation enterocolitis and/or sever leg edema. Severe radiation enterocolitis was strongly correlated with DM and smoking, and severe leg edema was strongly correlated with IB use.