Early radiation-induced mucosal changes evaluated by proctoscopy: predictive role of dosimetric parameters.
OBJECTIVE
Late rectal complications are assessed according to different scoring systems. Endoscopy can provide a more sensitive estimation of early radiation damage. The aim of this paper is to investigate the correlation between dosimetric parameters and rectal mucosal changes after radiotherapy (RT).


METHODS
Patients with prostate adenocarcinoma treated with curative or adjuvant RT underwent endoscopy 1 year after RT. Receiver operating characteristics (ROC) analysis was performed to analyze the predictive capability of the dosimetric variables in determining mucosal changes classified by Vienna Rectoscopy Score (VRS).


RESULTS
The best dosimetric predictors of grade ≥2 telangiectasia were rectal (r) V(60 Gy) (p=0.014), rV(70 Gy) (p=0.017) and rD(mean) (p=0.018). Similar results were obtained for grade ≥2 VRS. The set of rV(60 Gy)<34.4%, rV(70 Gy)<16.7% and rD(mean)<57.5 Gy was associated with a decreased risk of grade ≥2 telangiectasia and VRS.


CONCLUSIONS
rV(60 Gy), rV(70 Gy) and rD(mean) were the strongest predictors of rectal mucosal alterations. In-depth analysis is required to correlate each mucosal alteration with late rectal toxicity in order to suggest early proctoscopy as surrogate end-point for rectal late toxicity in studies aimed at reducing this important complication.
Fondazione di Ricerca e Cura Giovanni Paolo II, Università Cattolica del S. Cuore, Campobasso, Italy.
Edy
E
Ippolito
Francesco
F
Deodato
Gabriella
G
Macchia
Mariangela
M
Massaccesi
Cinzia
C
Digesù
Giuseppe A
GA
Pirozzi
Gianluca
G
Spera
Stefania
S
Marangi
Emanuele
E
Annoscia
Savino
S
Cilla
Angelo
A
Piermattei
Vincenzo
V
Valentini
Numa
N
Cellini
Marcello
M
Ingrosso
Alessio Giuseppe
AG
Morganti
D000230:Adenocarcinoma / Q000532:radiotherapy*; D000368:Aged; D006801:Humans; D007413:Intestinal Mucosa / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D011351:Proctoscopy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011878:Radiotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012007:Rectum / Q000528:radiation effects*; D013684:Telangiectasis / Q000209:etiology