Long-Term Results of Intraoperative Radiation Therapy for Early Breast Cancer Using a Nondedicated Linear Accelerator

Long-term follow-up outcomes of intraoperative radiotherapy for breast-conserving treatment in early breast cancer: A retrospective cohort study

Intraoperative radiotherapy (IORT) has been used as a novel therapeutic alternative for breast-conserving surgery (BCS) in patients with breast cancer. However, the long-term outcomes and safety of IORT in patients with breast cancer remain incompletely understood. Therefore, the present study aimed to explore the long-term outcomes of IORT following BCS, focusing on the oncological outcomes and cosmetic consequences compared with postoperative RT (PORT) in patients with breast cancer. Patients with early-stage breast cancer who underwent BCS followed by IORT or PORT between January 2016 and October 2020 at the Research Institute of General Surgery, Jinling Hospital, Nanjing Medical University (Nanjing, China), were retrospectively reviewed. After screening, a total of 59 patients were included in the present study and divided into two groups according RT records as follows: The IORT group (n=21) and the PORT group (n=38). The clinical data of all patients, including surgical and RT complications, cosmetic grading and scoring, and other events, were collected and retrospectively analyzed. No significant difference was observed in terms of the mean follow-up time in the IORT (5.89±1.57 years) and PORT (6.09±1.60 years) groups (P>0.05). Compared with PORT, IORT showed non-inferior therapeutic efficacy, with no significant differences in postoperative complications (surgical site infection and chronic pain; P>0.05). Notably, the IORT group achieved superior cosmetic outcomes, with 95.2% (20/21) of patients achieving a rating of excellent/good vs. 44.7% (17/38 patients) in the PORT group (P<0.001), alongside higher median cosmetic scores at all postoperative intervals (P<0.01). IORT also reduced healthcare utilization, shortening hospitalization by 23.8 days (12.1±5.1 vs. 35.9±3.5 days; P<0.001) and lowering costs significantly (33,117.98±6,281.17 vs. 77,789.55±7,000.90 CNY; P<0.001). These findings suggest that IORT offers comparable safety, improved cosmesis and greater cost-effectiveness than PORT, supporting its integration into clinical practice for eligible patients.

Intraoperative radiotherapy: An alternative to whole-breast external beam radiotherapy in the management of highly selective breast cancer: A SEER database analysis

OBJECTIVE

This study aimed to verify if intraoperative radiotherapy (IORT) can achieve the same survival outcome as whole-breast external beam radiotherapy (EBRT) in early breast cancer after breast-conserving surgery (BCS), and to explore the suitable candidates that can safely receive IORT after BCS.

METHODS

Eligible post-BCS patients who received IORT or EBRT were included in the Surveillance, Epidemiology and End Results (SEER) database from 2010 to 2018. Risk factors that affected 5-year overall survival (OS) or breast cancer specific survival (BCSS) were identified by Cox proportional hazards regression analysis. Clinical characteristics, OS, and BCSS were comparatively analyzed between the two treatment modalities.

RESULTS

The survival analysis after propensity score matching confirmed that patients who received IORT (n = 2200) had a better 5-year OS than those who received EBRT (n = 2200) (p = 0.015). However, the two groups did not differ significantly in 5-year BCSS (p = 0.381). This feature persisted even after multivariate analyses that took into account numerous clinical characteristics. Although there was no significant difference in BCSS between different subgroups of patients treated with IORT or EBRT, patients over 55 years of age, with T1, N0, non-triple negative breast cancers, hormone receptor-positive, and histologic grade II showed a better OS after receiving IORT.

CONCLUSION

In low-risk, early-stage breast cancer, IORT was not inferior to EBRT considering 5-year BCSS and OS. Considering the equivalent clinical outcome but less radiotoxicity, IORT might be a reasonable alternative to EBRT in highly selective patients undergoing BCS.