Purpose: To describe rectal mucosal damage in an endoscopic study after conformal radiotherapy of prostate cancer and to correlate this with clinical outcome.
Materials and methods: Flexible rectosigmoidoscopy was performed on 44 patients who voluntarily accepted the examination. The median follow-up was 29 months (20-41 months) after 3-D-planned conformal radiotherapy of prostate cancer (66 Gy at the ICRU Reference point, 2 Gy per fraction). To enable a systematic topographic description of endoscopic findings the rectum was divided into four sections. Additionally we differentiated between anterior, posterior, right and left lateral rectal wall. Due to the lack of an existing valid graduation system for radiation induced proctitis, we introduced a six-scaled rectoscopy score for describing and reporting endoscopic findings based on the standardization of the endoscopic terminology published by the ESGE (European Society for Gastrointestinal Endoscopy). Endoscopic findings were compared to the EORTC/RTOG morbidity score. In addition, since 3-D dose distribution of organs at risks was available, a correlation could be made between the location of the rectal lesions and the absorbed dose at that level.
Results: In general, endoscopic findings increased from the proximal rectum to the anorectal transition, as well as from the posterior to the anterior rectum wall. Telangiectasia grade 1 and 2 were observed at the whole circumference, only telangiectasia grade 3 were limited to the high dose region at the anterior rectum wall. Similar results were found for congested mucosa (reddening and edematous mucosa). Correlation with symptoms, 7/9 patients who suffered from intermittent rectal bleeding (EORTC/RTOG grade 2) had multiple telangiectasia grade 2-3 and/or congested mucosa grade 3 and microulcerations. However, the same extent of mucosal damage (rectoscopy score 2-3) was found in seven out of 35 patients who have never developed a period of macroscopic rectal bleeding.
Conclusion: Rectoscopy offers the possibility of detecting signs of tissue dysfunction below the level of subjective symptoms. Systematic analytic examinations such as rectoscopy, in addition to clinical examinations, as already foreseen in the LENT-SOMA-score, will be necessary due to the fact that even telangiectatic lesions have been observed for asymptomatic patients. For the opportunity of sharing and comparing data collected from endoscopy after radiotherapy a graduation system as proposed based on a standardisation of the endoscopic terminology will be necessary.