Long source-skin distance rectal irradiation technique: a review of results

This study reports the clinical outcome of fifteen patients with low rectal adenocarcinoma treated with the long source-skin distance (SSD) of endorectal irradiation technique. This method was designed at McGill University in 1986 as an alternative to the standard short SSD rectal irradiation that was developed by Papillon (Proc. R. Soc. Med. 66: 1179-1181, 1973).

Between April 1986 and May 1993, six females and nine males were treated with this technique. Fourteen patients were treated with curative intent and one woman for palliation. The median total dose was 85 Gy (range 60-135 Gy) in a median of 3 fractions (range 3-5) over a median treatment time of 5 weeks (range 2-9.5 weeks).

With a mean follow-up of 39 months and a median of 24 months (range 3 months-8.7 years), actuarial overall survival and disease-free survival rates are 50.8% and 71.4%, respectively, at 8.7 years. No patients have died of recurrent disease, but one patient has distant metastatic disease. One patient treated with curative intent required an abdominoperineal resection for progressive disease. Treatments were tolerated well by all patients. Four patients required steroid enemas for localized proctitis for a short period of time. They all responded well and had complete resolution of symptoms.

Our results are comparable with those in other reports in the literature. The complications are similar in type and frequency to other published series. The long SSD technique may be an acceptable alternative to the standard short SSD technique.