1 research outputs found
Minimally invasive tumor bed implant (MITBI) and peri-operative high-dose-rate brachytherapy (PHDRBT) for accelerated minimal breast irradiation (AMBI) or anticipated boost (A-PHDRBT-boost) in breast-conserving surgery for ductal carcinoma in situ
Purpose: To evaluate our institutional experience of minimally invasive tumor bed implantation (MITBI) during
breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) to deliver peri-operative high-dose-rate brachytherapy (PHDRBT) as accelerated minimal breast irradiation (AMBI) or anticipated boost (A-PHDRBT-boost).
Material and methods: Patients older than 40, with clinical and radiological unifocal DCIS < 3 cm were considered
potential candidates for accelerated partial breast irradiation (APBI) and were implanted during BCS using MITBItechnique. Patients who in final pathology reports showed free margins and no other microscopic tumor foci, received
AMBI with PHDRBT (3.4 Gy BID in 5 days). Patients with adverse features received A-PHDRBT-boost with post-operative external beam radiotherapy (EBRT).
Results: Forty-one patients were implanted, and 36 were treated and analyzed. According to final pathology,
24 (67%) patients were suitable for AMBI and 12 (33%) were qualified for A-PHDRBT-boost. Reoperation rate for those
with clear margins was 16.6% (6/36); this rate increased to 33% (4/12) for G3 histology, and 66% (4/6) were rescued
using AMBI. Early complications were documented in 5 patients (14%). With a median follow-up of 97 (range, 42-138)
months, 5-year rates of local, elsewhere, locoregional, and distant control were all 97.2%. 5-year ipsilateral breast tumor
recurrence rates (IBTR) were 5.6% (2/36), 8.3% (2/24) for AMBI, and 0% (0/12) for A-PHDRBT-boost patients. Both
instances of IBTR were confirmed G3 tumors in pre-operative biopsies; no IBTR was documented in G1-2 tumors.
Cosmetic outcomes were excellent/good in 96% of AMBI vs. 67% in A-PHDRBT-boost (p = 0.034).
Conclusions: The MITBI-PHDRBT program allows selection of patients with excellent prognoses (G1-2 DCIS with
negative margins and no multifocality), for whom AMBI could be a good alternative with low recurrence rate, decrease
of unnecessary radiation, treatment logistics improvement, and over-treatment reduction. Patients whose pre-operative biopsy showed G3 tumor, presents with inferior local control and more risk of reoperation due to positive margins