Reduced late rectal mucosal changes after prostate three-dimensional conformal radiotherapy with endorectal balloon as observed in repeated endoscopy.
OBJECTIVE
The aim of this study was to investigate prospectively the rectal wall (Rwall) spatial dose distribution, toxicity, and mucosal changes after prostate cancer radiotherapy with or without an endorectal balloon (ERB).


METHODS
A total of 24 patients with ERB and 24 without ERB (No-ERB) were treated with three-dimensional conformal radiotherapy (3D-CRT) to a dose of 67.5 Gy. The Rwall was divided into 16 mucosal areas and Rwall dose surface maps were constructed. After 3 months, 6 months, 1 year, and 2 years a rectosigmoidoscopy was performed, and each mucosal area was scored on telangiectasia, congestion, ulceration, stricture, and necrosis. Late rectal toxicity was correlated with the endoscopic findings.


RESULTS
The ERB significantly reduced the Rwall volume exposed to doses >40 Gy. Late rectal toxicity (grade >or=1, including excess of bowel movements and slight rectal discharge) was reduced significantly in the ERB group. A total of 146 endoscopies and 2,336 mucosal areas were analyzed. Telangiectases were most frequently seen and appeared after 6 months. At 1 and 2 years, significantly less high-grade telangiectasia (T 2-3) was observed in the ERB group at the lateral and posterior part of the Rwall. In mucosal areas exposed to doses >40 Gy, less high-grade telangiectases (T 2-3) were seen in the ERB group compared with the No-ERB group.


CONCLUSIONS
An ERB reduced the Rwall volume exposed to doses >40 Gy, resulting in reduction of late rectal mucosal changes and reduced late rectal toxicity. Although further analysis is needed, these data suggest an ERB-induced increased tolerance for late Rwall damage.
van Lin
Emile N J Th
EN
Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. E.vanLin@rther.umcn.nl
Kristinsson
Jón
J
Philippens
Mariëlle E P
ME
de Jong
Dirk J
DJ
van der Vight
Lisette P
LP
Kaanders
Johannes H A M
JH
Leer
Jan Willem
JW
Visser
Andries G
AG
D006471:Gastrointestinal Hemorrhage / Q000209:etiology; D006801:Humans; D007413:Intestinal Mucosa / Q000528:radiation effects*; D008297:Male; D011351:Proctoscopy / Q000379:methods; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000150:complications / Q000473:pathology / Q000517:prevention & control*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D012007:Rectum / Q000098:blood supply / Q000473:pathology / Q000528:radiation effects*; D012812:Sigmoidoscopy; D013684:Telangiectasis / Q000209:etiology / Q000473:pathology*