Breast cancer: primary treatment with external-beam radiation therapy and high-dose-rate iridium implantation.

Abstract

To evaluate a treatment for breast cancer and to demonstrate the safe use of iridium-192 high-dose-rate (HDR) implantations. In December 1984, the authors began to use HDR Ir-192 brachytherapy to deliver an interstitial boost to the primary site in conservative breast cancer treatment. By December 1989, 212 patients with 216 tumors were treated with external-beam irradiation of 45-50 Gy to the whole breast, which was followed by an interstitial 10-Gy boost. Median follow-up was 62 months (range, 36-101 months). Ten patients (10 of 216 breasts, 4.6%) developed local tumor recurrences, and 36 (17.0%) had distant metastases. At 5 years, overall survival was 88%, local tumor control was 96%, and disease-free survival was 81%. There were no serious complications. The use of an HDR source as a boost to the primary tumor site after external-beam radiation therapy with a dose of 10 Gy in one fraction is a safe procedure and does not negatively affect cosmetic appearance.