Efficacy of Small Bowel Displacement System in Post-Operative Pelvic Radiation Therapy of Rectal Cancer

Ahn, Yong Chan; Lim, Do Hoon; Kim, Moon Kyung; Wu, Hong Gyun; Kim, Dae Yong; Huh, Seung Jae

Abstract

PURPOSE: This study is to evaluate the efficacy of small bowel displacement system (SBDS) in post-operative pelvic radiation therapy (RT) of rectal cancer patients by measurement of small bowel volume included in the radiation fields receiving therapeutic dose. MATERIALS AND METHOD: Ten consecutive new rectal cancer patients referred to the department of Radiation Oncology of Samsung Medical Center in May of 1997 were included in this study. All patients were asked to drink Gastrographin before simulation and were laid prone for conventional simulation and CT scans with and without SBDS. The volume of opacified small bowel on CT scans, which was to be included in the radiation fields receiving therapeutic dose, was measured using picture archiving and communication system (PACS).
RESULTS
The average small bowel volumes with and without SBDS were 176.0ml (5.2- 415.6ml) and 185.1ml (54.5- 434.2ml), respectively. The changes of small bowel volume with SBDS compared to those without SBDS were more than 10% decrease in three, less than 10% decreaseintwo,lessthan10%increaseinthree,andmorethan10%increaseintwopatients.
CONCLUSION
No significant advantage of using SBDS in post-operative pelvic RT for rectal cancer patients has been shown by small bowel volume measurement using CT scan considering additional effort and time needed for simulation and treatment setup.