Prä- und postoperative Radiotherapie mit und ohne Chemotherapie beim Rectumcarcinom.

Locoregional failure occurs in up to about 30% of patients with advanced rectal cancer undergoing potentially curative surgery. The failure rate can be reduced by either pre- or postoperative adjuvant radiotherapy. Regarding the possible acute toxicity and late complications optimal techniques including irradiation in supine position with an accelerator and applying 3-4 field techniques are mandatory. High single doses and the so-called sandwich procedure should be avoided. Combined radiotherapy plus chemotherapy appears to be more efficient than irradiation of the pelvis alone. Reductions in the rate of pelvic and extrapelvic tumor recurrences which are not dramatic but of clinical significance seem to be followed by an improved survival. The 1990 Consensus Conference of the National Institute of Health recommended combined postoperative radiotherapy and chemotherapy for patients with T3 N0, T4 N0 and anyT N1-3 rectal cancer. For future trials the main goal has to be the optimization of combined radiotherapy plus chemotherapy. At present it is investigated whether 5-FU given as continuous infusion is superior to bolus application. The most important unanswered question is whether the highest therapeutic ratio is obtained by pre- or postoperative treatment.