Predictors of Grade 3 or Higher Late Bowel Toxicity in Patients Undergoing Pelvic Radiation for Cervical Cancer: Results From a Prospective Study

Journal Article · Sat Mar 01 04:00:00 EST 2014 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2013.11.214· OSTI ID:22416465

Chopra, Supriya ^[1]; Dora, Tapas ^[1]; Chinnachamy, Anand N. ^[2]; Thomas, Biji ^[1]; Kannan, Sadhna ^[3]; Mahantshetty, Umesh ^[2]; Phurailatpam, Reena; Paul, Siji N. ^[1]; Shrivastava, Shyam Kishore ^[2]

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1. Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai, Maharashtra (India)
2. Department of Radiation Oncology, Tata Memorial Hospital, Tata Memorial Centre, Parel, Mumbai, Maharashtra (India)
3. Epidemiology and Clinical Trials Unit, Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai, Maharashtra (India)

Purpose: The present study investigates relationship between dose–volume parameters and severe bowel toxicity after postoperative radiation treatment (PORT) for cervical cancer. Methods and Materials: From June 2010 to December 2012, a total of 71 patients undergoing PORT were included. Small bowel (SB) and large bowel (LB) loops were contoured 2 cm above the target volume. The volume of SB and LB that received 15 Gy, 30 Gy, and 40 Gy was calculated (V15 SB, V15 LB, V30 SB, V30 LB, V40 SB, V 40 LB). On follow-up, bowel toxicity was scored using Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. A reciever operating characteristic (ROC) curve identified volume thresholds that predicted for grade 3 or higher toxicity with highest specificity. All data was dichotomized across these identified cut-off values. Univariate and multivariate analysis was performed using SPSS, version 15. Results: The median patient age was 47 years (range, 35-65 years). Of the 71 patients, 46 received image-guided intensity modulated radiation therapy, and 25 received conformal radiation (50 Gy in 25 fractions for 5 weeks). Overall, 63 of 71 patients received concurrent chemotherapy. On a median follow-up of 18 months (range, 8-29 months), grade 2 or higher bowel toxicity was seen in 22 of 71 patients (30.9%) and grade 3 or higher bowel toxicity was seen in 9 patients (12.6%). On univariate analysis, V15 SB <275 cc (P=.01), V30 SB <190 cc (P=.02), V40 SB <150 cc (P=.01), and V15 LB <250 cc (P=.03), and V40 LB <90 cc (P=.04) predicted for absence of grade 3 or higher toxicity. No other patient- or treatment-related factors were statistically significant. On multivariate analysis, only V15 SB (P=.002) and V15 LB (P=.03) were statistically significant. Conclusions: V 15 Gy SB and LB are independent predictors of late grade 3 or higher toxicity. Restricting V15 SB and V15 LB to <275 cc and <250 cc can reduce grade 3 or higher toxicity to less than 5%.

• OSTI ID: 22416465
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 3 Vol. 88; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

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