Evaluating the efficacy of low-kV X-ray intraoperative radiotherapy in the treatment of locally advanced rectal cancer: a retrospective cohort study.

Background: Patients with locally advanced rectal cancer (LARC) treated with surgery have a high risk of local recurrence. Intraoperative radiotherapy (IORT) is a promising method for treating locally advanced solid tumors, but there is limited research on the efficacy of IORT in treating LARC. This study aimed to evaluate the long-term efficacy of low-kV X-ray IORT in the treatment of LARC. Methods: In total, 69 LARC patients with stage tumor Results: In total, 69 patients (median age, 64 years; 69.6% male) were enrolled in the study, and the median follow-up time was 47.5 months (range, 6.5-98.5 months). At the time of analysis, 15 patients had died (21.74%), 6 patients (8.70%) had been lost to follow-up, and 48 patients (69.57%) were alive. The 3-year OS and DFS rates were 89.42% and 71.47%, respectively. The local recurrence rate was 26.09%, and the 5-year local control, OS, and DFS rates were 78.90%, 68.59%, and 66.91%, respectively. The T stage of tumors was not predictive of either OS or DFS (P>0.05). However, different N stages and nerve/vascular invasion were found to be positively correlated with OS and DFS (P<0.05). Mortality within 30 days post-surgery was 0%. Early complications included anastomotic leak (5 cases, 7.25%), urinary retention (4 cases, 5.80%), diarrhea (7 cases, 10.14%), and bowel obstruction (4 cases, 5.80%), all of which were cured by conservative treatment. Late complications included ureteral obstruction (3 cases, 4.35%), bladder dysfunction (2 cases, 2.90%), sexual dysfunction (5 cases, 7.24%), and bowel obstruction (6 cases, 8.70%). Conclusions: Our findings suggest that low-kV X-ray IORT enhances local control and survival in LARC patients. Further research should be conducted in larger, prospective trials.