Electron and High-Dose-Rate Brachytherapy Boost in the Conservative Treatment of Stage I-II Breast Cancer

Abstract

Boost dose significantly improves LTC and RFS in patients treated with BCS and radiotherapy. In spite of the higher incidence of late side effects in the boost arm, boost dose is strongly recommended for patients at high risk for local recurrence. Positive or close margin status, high mitotic activity index, and young patient age should be viewed as absolute indications for tumor bed boost. LTC and cosmesis are excellent and similar to patients boosted with either HDR BT or electrons.

The Additional Irradiation of the Tumor Bed "The Boost" in the Breast Cancer Conservative Treatment: What Techniques?

“…found an aesthetic result significantly better with the brachytherapy (HDR) (70 against 88%, p<0.0001) [18], while the team of National Institute of Oncology of Budapest found same results [17]. Whatever is the considered dose rate, the best aesthetic results found in case of boost by brachytherapy can be explained by the "sub-dosage" of the skin surface (safety margin of 5 mm between the most superficial vectors and the skin) [23].…”

“…However, the vast majority of published studies comparing electron boost and boost LDR brachytherapy showed no significant difference in the rate of local control. The study of literature concerning the comparative efficiency between boost by brachytherapy (HDR) and by electrons found two studies, of which one randomized [17]. This study is a trial with double randomization, the first being made on the realization or not of the boost; the following is based on the technique of the boost (electrontherapy against brachytherapy HDR).…”

A importância da utilização de clips cirúrgicos na delimitação do volume de tratamento do reforço de dose no planejamento radioterápico

“…Nenhum estudo demonstrou benefício em sobrevida global com a adição do boost. Houve ganho estatisticamente significativo em sobrevida livre de recorrência local (Tabela 1) [14][15][16][17][18][19] . Romestaing et al randomizaram 1.024 pacientes com câncer de mama estádio inicial (<3 cm) tratados com cirurgia conservadora e radioterapia adjuvante de toda a mama com 50 Gy, em receber ou não boost de 10 Gy com elétrons no leito tumoral.…”

CT-Image Guided Brachytherapy

“…A supplementary tumor bed boost dose of 10-20 Gy (either through electrons, photons or an interstitial implants) is added to decrease the rate of local recurrence. The use of BT as additional irradiation to the tumor site with early stage breast cancer has increased significantly over the past several years (Polgar et al, 2002). The big advantage of BT above external beam radiotherapy (EBRT) results in much smaller and more conformal irradiation to the target volume due to the rapid dose fall-off (Frazier et al, 2001;Hammer et al, 2009).…”