[Value of radiotherapy in the treatment of rectal cancer].

In case of the rectum carcinoma radiotherapy can be applied as preoperative, intraoperative or postoperative measure, and in single cases also as exclusive therapeutic means. Multicentric studies revealed that preoperative radiotherapy helps to reduce the number of recurrences considerably. Postoperative radiotherapy has the advantage that the tumor volume becomes obvious and that only risk groups who profit from this therapy will be irradiated. Presently, a definite statement can not be made whether intraoperative radiotherapy will be able to further improve the results.