Feasibility and safety of repeat breast-conserving surgery with intraoperative irradiation for local breast carcinoma recurrences: A phase 2 trial.

Summary

In a multicenter, prospective phase II trial of selected patients with late in-breast recurrence, repeat breast-conserving surgery with intraoperative focal reirradiation achieved a 90.6% rate of no grade ≥2 fibrosis at 12 months, with durable local control and high mastectomy-free survival up to 60 months. These data support a one-day treatment alternative to salvage mastectomy for carefully selected cases.

Key Findings

• 90.6% (48/53) had no grade ≥2 breast fibrosis at 12 months after BCS + IOReIrr (95% CI: 79.3–96.9).
• Local recurrence-free survival was 96.8% at 36 months and 81.2% at 60 months.
• Mastectomy-free rates were 94.2% at 36 months and 92.3% at 60 months.
• Only three new local relapses occurred after the second BCS + IOReIrr during median 59-month follow-up.

Clinical Implications

For ER-positive, node-negative, small, late in-breast recurrences after prior whole-breast RT, a one-day repeat BCS with IOReIrr can be discussed as a safe, cosmetically favorable alternative to salvage mastectomy within shared decision-making.

Limitations

• Single-arm design without a concurrent control arm limits causal inference
• Restricted to selected low-risk recurrences; generalizability may be limited

Future Directions

Randomized comparisons against salvage mastectomy or external-beam reirradiation, integration with modern systemic therapies, and patient-reported outcomes focusing on cosmesis and quality of life.