High-dose-rate brachytherapy for early breast cancer: an ambulatory technique.

PURPOSE

To evaluate tolerance and efficiency of a boost dose delivered by high-dose-rate brachytherapy (HDRB) in conservative treatment of breast cancer. To evaluate the feasibility of brachytherapy on an out-patient basis.

METHODS

One hundred and six patients with T1-T2, N0-N1 breast cancers (108 breasts) have been treated with lumpectomy, external irradiation (45 Gy in 5 weeks), and a boost dose on the tumor bed with HDR iridium brachytherapy. Two fractions of 5 Gy were delivered 6 or 24 hours apart. Implantation was done during the lumpectomy (group A: 24 cases) or 3 to 4 weeks after the end of external irradiation (group B: 84 cases). For group B, the application was performed on local anesthesia, and did not require hospitalization. Characteristics of the population were as follows: T1: 77 (71.3%); T2: 31 (28.7%); median tumor size: 1.5 cm; histology: intraductal carcinomas (DCIS): 14 (13%); infiltrative ductal carcinomas (IDC): 84 (77.8%); others: 10 (9.2%). For IDC, surgical margins were found positive in 15 cases, and an extensive intraductal component was present in 22 cases.

RESULTS

All ambulatory HDR implants were performed as planned. No immediate toxicity was noticed, except 5 local hematomas. With a median follow-up of 45 months, 5 local relapses were observed (5-year local relapse rate: 5.1%). Only histological grade III was significantly correlated with local relapse. The 5-year disease-free survival and overall survival were respectively 93.8% and 93.3%. Cosmetic result was evaluated in 87 cases, and was good or excellent in 48 cases (63.2%), acceptable in 27 cases, and poor in 5 cases.

CONCLUSION

HDRB allows the boost dose to be performed on an out-patient basis. It seems to offer the same local control as other boost techniques for localized breast cancer with acceptable cosmetic results.