Resumen de Ten-year results of a phase II study with a single fraction of high-dose-rate brachytherapy (FAST-boost) after whole breast irradiation in invasive breast carcinoma
José Luis Guinot Rodríguez, Maribel Tortajada Azcutia, María Carrascosa Pérez, Vicente Crispín, Ana M. Otero Romero, Belén Ríos, Eleonor Rivín del Campo, Miguel Santos, Pablo Soler, Leoncio Arribas
Purpose We present the results of a prospective ten-year follow-up study to prove the effectiveness of a single fraction of 192-Ir high-dose-rate (HDR) brachytherapy (BT) as a boost.
Patients and methods Between 1999 and 2000, 84 consecutive patients with invasive breast carcinoma, with over 4 mm free margins after conservative surgery, were treated. All cases were stages T1�2, except for one case, a stage T3, 81% pN0, 19% pN1�2. Chemotherapy was used in 47% and hormonal therapy in 87%. Whole breast external beam radiotherapy (46 Gy) was followed 1�2 weeks later by an implant with metallic needles. A 7 Gy single dose of HDR BT to the 90% isodose line was delivered on an outpatient basis. Dosimetry was performed theoretically. This technique is called FAST-boost because the whole treatment is delivered in about two hours.
Results With a median follow-up of 120 months, three patients relapsed in the margin of the implant and two in a different quadrant (5/84, 6%). Actuarial local control at five and ten years was 98.5% and 95.6%. Overall survival was 92.7% and 90.2%, and disease-free survival 90.2% and 79.9%. Cosmetic results were good or excellent in 92.5%.
Conclusions A single-fraction HDR boost with rigid needles (FAST-boost) is a good, quick, simple technique when surgical margins are free.
