title: Comparative analysis of the effects of belly board and bladder distension in postoperative radiotherapy of rectal cancer patients.
abstract: OBJECTIVE
  To compare the effect of reducing the irradiated small-bowel volume with the use of belly board, bladder distension or both methods combined, in patients with rectal cancer undergoing postoperative pelvic radiotherapy.
  
  
  METHODS
  This study enrolled 20 consecutive patients with rectal cancer who were scheduled to receive postoperative pelvic radiotherapy. All patients underwent four sets of CT scans under four different methods as follows: group I: empty bladder without the use of a belly board; group II: empty bladder with the use of a belly board; group III: bladder distension without the use of a belly board; group IV: bladder distension with the use of a belly board. The conventional three-field treatment plan was made using a three-dimensional treatment planning system. The irradiated small-bowel volume was calculated at 10% intervals from 10% to 100% of the prescribed dose.
  
  
  RESULTS
  The volume of the irradiated small bowel decreased in the order of group I, group II, group III, and group IV at all dose levels (p < 0.001). In comparison to group I, the mean absolute volume reductions (relative volume reduction) of the irradiated small bowel were 41.5 +/- 20.1 cm(3) (33.9 +/- 12.9%) in group II, 76.6 +/- 30.5 cm(3) (55.1 +/- 17.8%) in group III, and 98.5 +/- 36.7 cm(3) (70.7 +/- 14.5%) in group IV.
  
  
  CONCLUSIONS
  Bladder distension was a more effective method than the belly board for reducing the irradiated small-bowel volume in postoperative pelvic radiotherapy of rectal cancer patients. The combination of the belly board and bladder distension showed an additive effect and was the most effective method for reducing the irradiated small-bowel volume.
authors.affiliation: Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, Korea.
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
authors.forename: Dae Yong
authors.initials: DY
authors.lastname: Kim
authors.forename: Kwan Ho
authors.initials: KH
authors.lastname: Cho
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Kim
authors.forename: Kyung Hae
authors.initials: KH
authors.lastname: Jung
authors.forename: Joong-Bae
authors.initials: JB
authors.lastname: Ahn
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Chang
authors.forename: Joo-Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Hyo Seong
authors.initials: HS
authors.lastname: Choi
authors.forename: Seok-Byung
authors.initials: SB
authors.lastname: Lim
authors.forename: Dae Kyung
authors.initials: DK
authors.lastname: Sohn
authors.forename: Seung-Yong
authors.initials: SY
authors.lastname: Jeong
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007421:Intestine, Small / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011182:Postoperative Care; D011829:Radiation Dosage; D011835:Radiation Protection; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012007:Rectum / Q000473:pathology; D014057:Tomography, X-Ray Computed; D001743:Urinary Bladder / Q000000981:diagnostic imaging