Objective: Although mastectomy has been traditional treatment for breast cancer after prior radiotherapy, patients are increasingly requesting additional breast conservation. This report details our experience of accelerated partial breast irradiation (APBI) as a component of salvage breast conserving treatment.
Methods: Eleven patients with prior external beam radiotherapy to the breast were treated with lumpectomy and APBI using high dose rate iridium-192 to a dose of 34 gray with 10 twice-daily fractions over 5 days. Six patients were previously treated for Hodgkin disease, 4 for invasive or in situ breast cancer, and 1 for soft tissue sarcoma. All had tumor ≤2 cm, negative nodes, and negative margins.
Results: At median follow-up of 53.7 months, 10 patients were alive without evidence of disease recurrence following treatment which occurred at median interval of 19.1 years after prior radiotherapy. One was lost to follow-up. One developed mastitis under treatment requiring oral and IV antibiotics. Another received oral antibiotics for 6 weeks following formation of a draining sinus tract with contracture and painless fibrosis. Three others reported slight to moderate firmness. Four noted mild hyperpigmentation, but none developed telangiectasia. One patient with prior whole breast radiation had necrosis requiring mastectomy 9.4 months following retreatment, with pathology revealing a chronic breast abscess. Of the 9 women with successful breast conservation, all but one reported satisfaction pursuing breast conservation rather than mastectomy.
Conclusions: Repeat lumpectomy and APBI for in-breast tumor recurrence after prior external beam radiotherapy has been delivered with acceptable outcomes, justifying a phase II multicenter trial for validation.