EFFECT OF CUSTOMIZED SMALL-BOWEL DISPLACEMENT SYSTEM IN PELVIC IRRADIATION

Purpose: Authors designed a customized small bowel displacement system (SBDS) to displace the small bowel out of the pelvic radiation fields and to minimize treatment related bowel morbidity. Methods and Materi als: From August 1995 to May 1996, 55 consecutive patients who receive d pelvic radiation therapy with the SBDS were included in this study. The SBDS consists of a customized Styrofoam compression device that ca n displace the small bowel out of the radiation fields and an individu alized immobilization abdominal board for easy daily setup of the pati ent in prone position. After opacifying the small bowel,vith barium, t he patients were laid prone and posterior-anterior (PA) and lateral (L AT) simulation films mere taken with and without the SBDS. The volume of the small bowel included in the radiation fields with and without t he SBDS were compared. Results: Using the SBDS, the mean small bowel v olume was reduced by 59% an PA and 51% on LAT films (p = 0.0001). In s ix patients (6 of 55, 11%), it was possible that no small bowel was in cluded within the treatment fields. The mean upward displacement of th e most caudal small bowel was 4.8 cm using the SBDS. Patients treated with the SBDS manifested a significantly lower incidence of diarrhea r equiring medication (8 of 55, 15%) vs. those without the SBDS (23 of 3 9, 62%) (p < 0.05). Conclusion: The SBDS is a novel method that can be used to displace the small bowel away from the treatment portal effec tively and to reduce the radiation therapy morbidity. Compliance with setup is excellent. (C) 1998 Elsevier Science Inc.