LONG-TERM OUTCOME WITH INTERSTITIAL BRACHYTHERAPY IN THE MANAGEMENT OF PATIENTS WITH EARLY-STAGE BREAST-CANCER TREATED WITH BREAST-CONSERVING THERAPY

Purpose: We reviewed our institution's experience with interstitial im plant boosts to determine their long-term impact on local control and cosmetic results. Methods and Materials: Between January 1, 1980 and D ecember 31, 1987, 390 women with 400 cases of Stage I and II breast ca ncer were managed with breast-conserving therapy (BCT) at William Beau mont Hospital. All patients were treated with an excisional biopsy and 253 (63 %) underwent reexcision. Radiation consisted of 45-50 Gy exte rnal beam irradiation to the whole breast followed by a boost to the t umor bed to at least 60 Gy using either electrons [108], photons [15], or an interstitial implant [277] with either Ir-192 [190] or I-125 [8 7], Longterm local control and cosmetic outcome were assessed and cont rasted between patients boosted with either interstitial implants, ele ctrons, or photons. Results: With a median follow-up of 81 months, 25 patients have recurred in the treated breast for a 5- and 8-year actua rial rate of local recurrence of 4 and 8%, respectively. There were no statistically significant differences in the 5- or 8-year actuarial r ates of local recurrence using either electrons, photons, or an inters titial implant. Greater than 90% of patients obtained a good or excell ent cosmetic result, and no statistically significant differences in c osmetic outcome were seen whether electrons, photons, or implants were used.Conclusions: We conclude that patients with Stage I and II breas t cancer undergoing BCT and judged to be candidates for boosts can be effectively managed with LDR interstitial brachytherapy. Long-term loc al control and cosmetic outcome are excellent and similar to patients boosted with either electrons or photons. (C) 1997 Elsevier Science In c.