The Relationship between Chronic Bowel Dysfunction and the Small Bowel Dose Volume Histogram of Rectal Cancer Survivors

Abstract

Materials/Methods: Billing records and tumor registry were used to identify all living patients treated with RT for rectal cancer between January 1996 and January 2009. After exclusions for stomas, active metastatic disease, no 3D treatment planning, inadequate small bowel contrast, unrecoverable treatment data, repeat pelvic RT, wide local excision/no surgery, lost to follow-up, incapacitation from other disease, or declining participation, the remaining patients answered a validated 18 item questionnaire (Temple, et al. Diseases Colon Rectum 2005;48:1353-65). This resulted in a frequency score, a dietary score, an urgency/soilage score, and four scores from independent questions. These seven scores were tested using linear regression to evaluate the correlation the absolute small bowel volume for each dose at 5 Gy increments. The Student’s unpaired t test and Pearson chi-square/Fisher’s Exact test were used to compare continuous and categorical variables between preoperative and postoperative groups, respectively. A p value of 0.05 was considered statistically significant. Statistical analyses were performed with SPSS Version 17.0 (SPSS Inc., Chicago, IL), and all statistical tests were two-sided.