Hôpital Saint Louis, service de cancérologie-radiothérapie, 1 avenue Claude Vellefaux, 75010 Paris, France
With the aim of decreasing local relapses in locally advanced rectal cancer, two types of preoperative radiotherapy protocols have been developed in the past: short course radiotherapy consisting of 5 fractions of 5 Gy delivered within one week and long course radiotherapy consisting of 5 fractions of 1.8 to 2 Gy per week delivered within 5 weeks in concomitant association with fluoropyrimidine-based chemotherapy. Randomized studies did not found any difference in terms of efficacy or side effects between short and long course radiotherapy protocols. The advantage of using long course radiotherapy is the possibility to obtain both tumor downsizing and downstaging. Those effects could be advantageously used in sphincter sparing surgery strategy for tumors located in the lower rectum or to obtain clear surgical resection margins in case of tumor close to the fascia recti.