Acute toxicity and tumor response in locally advanced rectal cancer after preoperative chemoradiotherapy with shortening of the overall treatment time using intensity-modulated radiotherapy with simultaneous integrated boost - A phase II trial
Mené sur 51 patients atteints d'un adénocarcinome rectal de stade II-III traité entre 2014 et 2015, cet essai de phase II évalue l'efficacité, du point de vue de la réponse complète pathologique, et la tolérabilité d'un traitement pré-opératoire combinant de façon concomitante une radiothérapie avec modulation d'intensité, ciblant la tumeur et la région pelvienne, et une chimiothérapie par capécitabine
Background and Purpose : This phase II study investigated the efficacy and safety of preoperative intensity modulated radiotherapy with a simultaneous integrated boost (IMRT-SIB) without dose escalation, concomitant with standard capecitabine chemotherapy in locally advanced rectal cancer. Materials and Methods : Between January 2014 and March 2015, 51 patients with operable, stage II-III rectal adenocarcinoma received preoperative IMRT with pelvic dose of 41.8 Gy and simultaneously delivered 46.2 Gy to T2/3 and 48.4 Gy to T4 tumor in 22 fractions, concomitant with capecitabine, 825mg/m2/12h, including weekends. Primary endpoint was pathologic complete response (pCR). Results : Fifty patients completed preoperative treatment per protocol, and 47 underwent surgical resection. The sphincter preservation rate for the low rectal tumors was 62% and resection margins were free in all but one patient. Decrease in tumor and nodal stage was observed in 32 (68%) and 39 (83%) patients, respectively, with pCR achieved in 12 (25.5%) patients. There were only two G≥3 acute toxicities, with infectious enterocolitis in one and dermatitis over the sacral area due to the bolus effect of the treatment table in the second patient. Conclusions : Preoperative IMRT-SIB without dose escalation is well tolerated with a low acute toxicity profile and can achieve a high rate of pCR and downstaging.
http://www.redjournal.org/article/S0360-3016(16)33146-7/fulltext