TOPLINE:

Repeat breast-conserving surgery (BCS) combined with intraoperative reirradiation was feasible and safe for patients with late recurrence of ipsilateral breast tumour, with more than 90% of patients not developing breast fibrosis of grade 2 or higher at 12 months.

METHODOLOGY:

• Researchers conducted a prospective, multicentre, single-arm phase 2 trial including 53 patients (median age, 68 years) with late recurrence of ipsilateral breast tumour at eight centres in France from January 2015 to April 2018.
• Patients underwent repeat BCS combined with a single intraoperative irradiation dose of 20 Gy delivered via the INTRABEAM system.
• The primary outcome was the absence of breast fibrosis of grade 2 or higher at 12 months post-treatment, assessed using the Common Terminology Criteria for Adverse Events, version 4.0.
• Secondary outcomes included the cumulative incidence of local relapse, local relapse-free survival, distant metastasis-free survival, disease-free survival, overall survival, and mastectomy-free survival; quality of life (QOL); and patient satisfaction.

TAKEAWAY:

• At 12 months post-intraoperative irradiation, 48 of 53 patients (90.6%; 95% CI, 79.3%-96.9%) had not developed breast fibrosis of grade 2 or higher, meeting the primary endpoint and demonstrating acceptable tolerability.
• During a median follow-up of 59 months, only three patients experienced a new local recurrence, yielding a 60-month cumulative incidence of local relapse of 5.6% (95% CI, 1.8%-16.3%) and a 60-month local relapse-free survival rate of 81.2% (95% CI, 65.2%-90.3%).
• The 60-month mastectomy-free survival rate was 92.3% (95% CI, 80.7%-97.0%), indicating that most patients avoided mastectomy, and the 60-month overall survival rate was 84.9% (95% CI, 68.9%-93.1%), with only one patient developing metastatic progression.
• QOL scores remained stable from baseline to 24 months, with high scores observed for physical, role, cognitive, and social functioning and body image. Patient satisfaction with the treatment strategy reached 100% at 48 months post-treatment.

IN PRACTICE:

"Based on [the study] results, shared decision-making about this 'one-day treatment' [intraoperative irradiation with second BCS] vs salvage mastectomy can be safely proposed," the authors wrote.

SOURCE:

This study was led by Claire Lemanski, Fédération Universitaire d'Oncologie Radiothérapie d'Occitanie Méditerranée, Institut régional du Cancer de Montpellier (ICM), Montpellier, France. It was published online on April 17, 2026, in Radiotherapy and Oncology.

LIMITATIONS:

The single-arm design in the study without a randomised control group limited the ability to directly compare outcomes with those of salvage mastectomy, the current standard of care. The relatively small sample size may have affected the statistical power and generalisability of the findings.

DISCLOSURES:

The research was supported by a grant provided by the French National Cancer Institute. The authors reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.