Morales Marta Gimeno, Martinez-Regueira Fernando, Rodriguez-Spiteri Natalia, Olartecoechea Begoña, Rubio Isabel, Esgueva Antonio, Pina Luis, Elizalde Arlette, Sampedro Carolina Sobrido, Idoate Miguel Angel, Abengozar Marta, Ramos Luis, Manuel Felipe Calvo, Martínez-Monge Rafael, Cambeiro Mauricio
Department of Oncology, University of Navarra, Pamplona-Madrid, Spain.
Breast Surgical Oncology Unit, University of Navarra, Pamplona-Madrid, Spain.
J Contemp Brachytherapy. 2020 Dec;12(6):521-532. doi: 10.5114/jcb.2020.101684. Epub 2020 Dec 16.
To evaluate our institutional experience of minimally invasive tumor bed implantation (MITBI) during breast-conserving surgery (BCS) for ductal carcinoma (DCIS) to deliver peri-operative high-dose-rate brachytherapy (PHDRBT) as accelerated minimal breast irradiation (AMBI) or anticipated boost (A-PHDRBT-boost).
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 MITBI-technique. 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).
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 ( = 0.034).
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.
评估我们机构在保乳手术（BCS）期间对导管原位癌（DCIS）进行微创肿瘤床植入（MITBI）的经验，以实施围手术期高剂量率近距离放疗（PHDRBT）作为加速部分乳腺照射（AMBI）或预期推量照射（A-PHDRBT-推量）。
年龄大于40岁、临床及影像学表现为单灶性DCIS且直径<3 cm的患者被视为加速部分乳腺照射（APBI）的潜在候选者，并在BCS期间采用MITBI技术进行植入。最终病理报告显示切缘阴性且无其他微小肿瘤病灶的患者，接受AMBI联合PHDRBT（5天内每日两次，每次3.4 Gy）。具有不良特征的患者接受A-PHDRBT-推量联合术后外照射放疗（EBRT）。
41例患者进行了植入，36例接受治疗并进行分析。根据最终病理结果，24例（67%）患者适合AMBI，12例（33%）符合A-PHDRBT-推量标准。切缘阴性患者的再次手术率为16.6%（6/36）；G3组织学类型患者的该比率增至33%（4/12），其中66%（4/6）通过AMBI挽救。5例患者（14%）记录有早期并发症。中位随访97（范围42 - 138）个月，局部、其他部位、区域及远处控制的5年率均为97.2%。5年同侧乳腺肿瘤复发率（IBTR）为5.6%（2/36），AMBI组为8.3%（2/24），A-PHDRBT-推量组为0%（0/12）。两例IBTR在术前活检中均确诊为G3肿瘤；G1 - 2肿瘤未记录有IBTR。AMBI组96%的美容效果为优/良，而A-PHDRBT-推量组为67%（P = 0.034）。
MITBI-PHDRBT方案允许选择预后良好的患者（切缘阴性、无多灶性的G1 - 2 DCIS），对于他们而言，AMBI可能是一种良好的替代方案，具有低复发率、减少不必要的放疗、改善治疗流程以及减少过度治疗等优点。术前活检显示为G3肿瘤的患者，局部控制较差，因切缘阳性再次手术的风险更高。
