Intraoperative low-dose rate brachytherapy as an adjunct to surgery for marginally resectable rectal and recurrent anorectal carcinomas.

Background: Locally recurrent and marginally resectable rectal and anorectal carcinomas present significant therapeutic challenges due to high recurrence rates and limited treatment options. Intraoperative low-dose rate brachytherapy (LDRBT) has emerged as a potential adjunct to improve local control in these cases. This study aims to evaluate the clinical outcomes associated with intraoperative LDRBT for these difficult cases.

Methods: This was a retrospective study that was approved by the institutional review board. Patients who had undergone intraoperative pelvic LDRBT for locally recurrent and marginally resectable rectal and anorectal carcinomas between February 2004 and April 2022 were included. Morbidity and survival were assessed using toxicity CTCAE V5.0 and Kaplan-Meyer curves, respectively.

Results: 29 patients were found to have been treated with surgical resection and intraoperative pelvic seed brachytherapy with either I-125 or Cs-131. The 1-year and 2-year overall survival rates were 88.7% (95% CI, 69.0-96.2) and 70.6% (95% CI, 47.7-84.9), respectively. Furthermore, the 1-year and 2-year local progression free survival rates were 55.4% (95% CI, 34.9-71.8) and 41.7% (95% CI, 22.3-60.1), respectively. Median number of months for local progression free survival was 15.6% (95% CI, 7.4-34.4). The most common toxicity was Grade 1-2 neuralgia in 41.4% of patients, with no Grade 4 or higher observed.

Conclusion: Our results suggest that intraoperative LDRBT may play a broader role in managing these challenging conditions. Morbidity was moderate and primarily dependent on disease progression. Survival and progression rates were consistent with published reports, highlighting the therapeutic potential of this treatment approach.