Impact of boost technique on outcome in early-stage breast cancer patientstreated with breast-conserving therapy

We reviewed our institution's experience treating early-stage breast cancer patients with breast-conserving therapy (BCT) to determine the impact of b oost technique on outcome. A total of 552 patients with stage I and II brea st cancer were managed with BCT. All patients were treated with a partial m astectomy and radiation therapy (RT). RT consisted of 45 Gy to 50 Gy extern al beam irradiation to the whole breast followed by a boost to the tumor be d using either electrons (232 patients), photons (15 patients), or an inter stitial implant (316 patients). Local control and cosmetic outcome was comp ared among three patient groups based on the type of boost used. Forty-one patients had a recurrence of cancer in the treated breast for 5-. 10-, and 13-year actuarial local recurrence rates of 2.8%, 7.5%. and 11.2%. respecti vely. There were no significant differences in the local recurrence rates o r cosmetic outcome using electrons, photons, or an interstitial implant. On multivariate analysis, only young age and margin status were associated wi th local recurrence. Stage I and II breast cancer patients undergoing BCT c an be effectively managed with electron, photon, or interstitial implant bo ost techniques. Long-term local control and cosmetic outcome are excellent regardless of which boost technique is used.