Introduction
toxicity
RECTAL CANCER
Radiation therapy (RT) is typically applied using one of two standard approaches for preoperative treatment of resectable locally advanced rectal cancer (LARC): short-course RT (SC-RT) alone or long-course RT (LC-RT) with concurrent fluorouracil (5-FU) chemotherapy. The Phase II single-arm KROG 11-02 study using intermediate-course (IC) (33 Gy (Gray)/10 fr (fraction) with concurrent capecitabine) preoperative chemoradiotherapy (CRT) demonstrated a pathologically complete response rate and a sphincter-sparing rate that were close to those of LC-CRT. The current trial aim to compare the pathological/oncological outcomes, toxicity, and quality of life results of LC-CRT and IC-CRT in cases of LARC. The prescribed dose was 33 Gy/10 fr for the IC-CRT group and 50.4 Gy/28 fr for the LC-CRT group. Concurrent chronomodulated capecitabine (Brunch regimen) 1650 mg/mThe standard approaches to the use of radiation therapy (RT) in the preoperative treatment of resectable rectal cancer were short-course radiotherapy (SC-RT) alone or long-course chemoradiotherapy (LC-CRT) until recent years, although current treatment approach is to apply RT within total neoadjuvant therapy protocol [At present, data on the likelihood of using an intermediate-course of CRT (IC-CRT) without compromising the established effectiveness of LC-CRT in LARC patients are scarce [To the best of our knowledge, the only study to date to examine the utility of IC-CRT in T3-4/N0+ rectal cancer patients is a phase II single-arm study from Korea (KROG 11-02), which used an IC regimen of 33 Gy (Gray)/10 fr (fraction) with concurrent capecitabine [The present phase II randomized trial is the first known investigation in the literature to compare the efficacy of LC-CRT and IC-CRT in the management of LARC in terms of pathological and oncological outcomes, toxicity, and quality of life (QoL) status.