High-dose-rate intraluminal brachytherapy during preoperative chemoradiation for locally advanced rectal cancers.

Aim: To determine the feasibility and safety of high dose rate intraluminal brachytherapy (HDR-ILBT) boost during preoperative chemoradiation for rectal cancer.

Methods: Between 2008 and 2009, thirty-six patients with locally advanced rectal cancer (≥ T3 or N+), were treated initially with concurrent capecitabine (825 mg/m(2) oral twice daily) and pelvic external beam radiotherapy (EBRT) (45 Gy in 25 fractions), then were randomized to group A; HDR-ILBT group (n = 17) to receive 5.5-7 Gy × 2 to gross tumor volume (GTV) and group B; EBRT group (n = 19) to receive 5.4 Gy × 3 fractions to GTV with EBRT. All patients underwent total mesorectal excision.

Results: Grade 3 acute toxicities were registered in 12 patients (70.6%) in group A and in 8 (42.1%) in group B. Complete pathologic response of T stage (ypT0) in group A was registered in 10 patients (58.8%) and in group B, 3 patients (15.8%) had ypT0 (P < 0.0001). Sphincter preservation was reported in 6/9 patients (66.7%) in group A and in 5/10 patients (50%) in group B (P < 0.01). Overall radiological response was 68.15% and 66.04% in Group A and B, respectively. During a median follow up of 18 mo, late grade 1 and 2 sequelae were registered in 3 patients (17.6%) and 4 patients (21.1%) in the groups A and B, respectively.

Conclusion: HDR-ILBT was found to be effective dose escalation technique in preoperative chemoradiation for rectal cancers, with higher response rates, downstaging and with manageable acute toxicities.