Local Pelvic Relapses after Neoadjuvant High-dose Rate Endorectal Brachytherapy for Patients with Operable Rectal Cancer

Abstract

This article reports on the pattern of pelvic relapse after targeted radiation therapy to the primary tumor bed using high-dose rate endorectal brachytherapy (HDREBT) for patients with operable rectal cancer. Three hundred twenty-five patients were treated with neoadjuvant HDREBT using 26 Gy in four fractions prescribed to the macroscopic disease documented on MRI. Imaging studies including abdominal and pelvic CT scans were performed every 6 months during the first 2 years, then yearly until year 5. The median follow-up is presently 52 months. At 5 years, the actuarial local recurrence rate is 4.7%, disease-free survival is 68%, and overall survival is 71%. The primary tumor bed tumor is the dominant pattern compared with nodal relapse in patients treated with HDREBT alone. Our experience suggests that in the era of total mesorectal excision surgery, pelvic nodal relapse is uncommon.