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 tumornodemetastasis (TNM) treated with radical resection and low-kV X-ray IORT at our center from December 2015 to August 2023 were consecutively included in this retrospective cohort study. Basic patient characteristics, intraoperative and postoperative data, and early and late complications were recorded. A Kaplan-Meier (K-M) survival analysis was performed to analyze the overall survival (OS) and disease-free survival (DFS) of the patients.

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.