Five-fraction partial breast re-irradiation showed low toxicity after repeat lumpectomy

Twenty-five selected patients had 96% crude local control and no grade 3 toxicity after 26 Gy in five fractions.

KEY POINTS

  • This retrospective study identified 25 consecutively treated women with ipsilateral breast tumour recurrence after previous lumpectomy and whole-breast irradiation. All declined salvage mastectomy and a more prolonged hyperfractionated re-irradiation schedule.
  • The cohort was highly selected: median age was 70 years, median interval from initial breast-conserving treatment was 16.6 years, median recurrent tumour size was 1.2 cm, 96% had stage 0–I disease, 92% were oestrogen-receptor positive and all were clinically node negative with clear margins.
  • All patients received volumetric modulated arc therapy delivering 26 Gy in five consecutive daily fractions. Two patients with less favourable features received a simultaneous integrated boost to 30 Gy in five fractions.
  • The clinical target volume included the lumpectomy cavity plus 1.5 cm, with a 5 mm planning target volume expansion. Median planning target volume was 191 cm³, representing 18% of the breast; median planning target volume V95% was 99.86%.
  • Median mean heart dose was 0.44 Gy, and median mean left anterior descending coronary artery dose in left-sided cases was 1.18 Gy. Three patients with left-sided tumours were treated using deep-inspiration breath hold.
  • All acute adverse events were grade 1. Dermatitis occurred in 44%, breast oedema in 12–13%, breast pain in 8% and fatigue in 8%; no pneumonitis, desquamation or grade 2 or higher acute event occurred.
  • At a median follow-up of 13 months, one patient developed another ipsilateral recurrence, giving 96% crude local control. No regional recurrence, distant metastasis or death occurred; no grade 3 or higher late toxicity was observed, although breast shrinkage and fibrosis were present in 50% and 48%, and excellent or good cosmesis was maintained in 71%.

CLINICAL TAKEAWAY

Five-fraction partial breast re-irradiation appears technically feasible for carefully selected patients with small, favourable recurrences after a long disease-free interval. It remains an experimental alternative rather than an established equivalent to salvage mastectomy or better-studied re-irradiation schedules because follow-up was too short to evaluate durable control, fibrosis and cosmetic deterioration reliably.

SOURCE

Advances in Radiation Oncology