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Updated: Jul 16, 2025
Robot-assisted Total Mesorectal Excision and Lateral Pelvic Lymph Node Dissection for Locally Advanced Middle-low Rectal Cancer
Published on: February 12, 2022
Postchemoradiation magnetic resonance imaging circumferential resection margin predicts treatment failure after
Sun Jung Kim1, Yong Joon Lee1, Min Young Park1
1Department of Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
Background:
This study aimed to review the magnetic resonance imaging (MRI) features of patients with low rectal cancer (LRC) undergoing preoperative chemoradiotherapy (CRT) and investigate the risk factors for treatment failure after sphincter preserving surgery following preoperative CRT based on multidisciplinary approach.
Objectives:
Patients who underwent standard CRT and sphincter preserving radical surgery for LRC between January 2000 and December 2011 were retrospectively reviewed. Sphincter preservation failure (SPF) was defined as any one of the following: positive pathologic circumferential resection margin, local recurrence, failure to repair ileostomy, or permanent stoma formation due to anastomotic complications.
Results:
Among the 191 patients, there were no overall significant differences between sphincter preservation success (n = 161) and SPF (n = 30) groups. SPF group showed a higher MRI circumferential resection margins (mrCRM) positive rate before and after CRT (before CRT: 33.3% vs. 16.1%, p = 0.027; after CRT: 23.3% vs. 6.2%, p = 0.002). Multivariate analysis showed that only mrCRM after CRT was associated with SPF (hazard ratio = 4.596, p = 0.005). SPF group showed worse 5-year cancer-specific survival (51% vs. 92.7%, p < 0.001).
Conclusions:
MRI-based assessment of the tumor after CRT plays a crucial role in predicting the success and feasibility of sphincter preservation as well as oncological outcomes in patients with LRC.
