MedAustron, Center for Ion Therapy and Research, Wiener Neustadt, Austria.
Department of Radiation Oncology, Medical Faculty, Christian-Albrechts-University, Kiel, Germany.
Jpn J Clin Oncol. 2020 Jul 9;50(7):743-752. doi: 10.1093/jjco/hyaa064.
Accelerated partial breast irradiation (APBI) delivers a short course of adjuvant RT after breast conserving surgery to only a limited part of the breast where the tumor was located. This procedure requires expertise, good communication, and close collaboration between specialized surgeons and attending radiation oncologists with adequate intraoperative tumor bed clip marking. However, APBI offers several intrinsic benefits when compared with whole breast irradiation (WBIR) including reduced treatment time (1 versus 4-6 weeks) and better sparing of surrounding healthy tissues. The present publication reviews the APBI level 1-evidence provided with various radiation techniques supplemented by long-term experience obtained from large multi-institutional phase II studies. Additionally, it offers an outlook on recent research with ultra-short or single-fraction APBI courses and new brachytherapy sources. Mature data from three randomized controlled trials (RCTs) clearly prove the noninferiority of APBI with 'only two techniques-1/MIBT (multicatheter interstitial brachytherapy) (two trials) and 2/intensity modulated radiotherapy (one trial)'-in terms of equivalent local control/overall survival to the previous standard 'conventionally fractionated WBIR'. However, MIBT-APBI techniques were superior in both toxicity and patient-reported outcomes (PROs) versus WBIR at long-term follow-up. Currently, in RCT-setting, alternative APBI techniques such as intraoperative electrons, 50-kV x-rays and three-dimensional conformal external beam radiotherapy (3D-CRT) failed to demonstrate noninferiority to conventionally fractionated WBIR. However, 3D-CRT-APBI compared noninferior to hypo-fractionated WBIR in preventing ipsilateral breast tumor recurrence (randomized RAPID-trial) but was associated with a higher rate of late radiation toxicity. Ultimately, MIBT remains the only APBI modality with noninferior survival/superior toxicity/PROs at 10-years and therefore should be prioritized over alternative methods in patients with breast cancer considered at low-risk for local recurrence according to recent international guidelines.
加速部分乳房照射（APBI）在保乳手术后仅对肿瘤所在的乳房有限部分进行辅助放射治疗。该程序需要专业知识、良好的沟通以及专门的外科医生和主治放射肿瘤学家之间的密切合作，术中肿瘤床夹标记要充分。然而，与全乳房照射（WBIR）相比，APBI 具有许多内在优势，包括治疗时间缩短（1 周与 4-6 周）和周围健康组织的更好保护。本出版物回顾了 APBI 1 级证据，以及各种放射技术的补充，并提供了来自大型多机构 II 期研究的长期经验。此外，它还展望了最近关于超短或单次 APBI 课程和新近距离放射治疗源的研究。来自三项随机对照试验（RCT）的成熟数据清楚地证明了“只有两种技术-1/MIBT（多导管间质近距离放疗）（两项试验）和 2/调强放疗（一项试验）”的 APBI 与之前的标准“常规分割 WBIR”在局部控制/总生存率方面具有非劣效性。然而，在长期随访中，MIBT-APBI 技术在毒性和患者报告的结果（PROs）方面均优于 WBIR。目前，在 RCT 环境中，替代 APBI 技术，如术中电子、50kV X 射线和三维适形外部束放射治疗（3D-CRT），未能证明与常规分割 WBIR 具有非劣效性。然而，3D-CRT-APBI 与低分割 WBIR 相比，在预防同侧乳房肿瘤复发方面具有非劣效性（随机 RAPID 试验），但与晚期放射毒性发生率较高相关。最终，MIBT 仍然是唯一一种在 10 年时具有非劣效生存/优越毒性/PROs 的 APBI 方式，因此根据最近的国际指南，对于局部复发风险低的乳腺癌患者，应优先考虑替代方法。
