Breast conservation treatment with perioperative interstitial irradiation

Limited resection of the breast combined with radiation has proved to be as effective as more radical surgery in treating early breast cancer. At the University of Kansas Medical Center, the radiotherapy consists of an interstitial implant at the time of lumpectomy to deliver an interstitial boost dose to the tumor bed with iridium-192 immediately following the surgical procedure. An axillary node dissection is also performed at the time of lumpectomy. A dose of 2,000 cGy is delivered to the tumor bed between 40 and 60 h. Two to three weeks later, 4,500-5,000 cGy is delivered to the entire breast with external beam radiation over 5-5.5 weeks. One hundred breasts in 98 patients were so treated between June 1982 and February 1986, with 2 carcinomas in situ, 40 stage I, 51 stage II, and 7 stage III cancers, consisting of 2 TIS, 54 T1, 39 T2, and 5 T3 lesions. Locoregional control with a median follow-up of 31 months was 98%. One recurrence was in a different quadrant, and the other revealed predominantly the in situ component. Immediate implant did not compromise wound healing or cosmesis. The cosmetic result was graded as good to excellent in 88% of the breasts. Our preliminary results appear to suggest a better local control with immediate interstitial irradiation.