Intraoperative or postoperative radiotherapy boost in high-risk breast cancer: a matched-pair analysis.

IF 2.8 3区医学 Q3 ONCOLOGY

Strahlentherapie und Onkologie Pub Date : 2026-09-17 DOI:10.1007/s00066-026-02592-3

Gustavo R Sarria, Cas Dejonckheere, Jorge Fernandez, Jose Burgos, Adela Heredia, Eleni Gkika, Gustavo J Sarria, Paola Fuentes-Rivera

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引用次数: 0

Abstract

Purpose: The optimal boost technique following breast-conserving surgery for patients with high-risk early breast cancer remains controversial. This study compared oncologic outcomes following an intraoperative radiotherapy (IORT) boost using low-energy X‑rays with those of a conventional external beam radiotherapy (EBRT) boost in a matched-pair cohort.

Methods: Patients treated with breast-conserving surgery followed by either an upfront IORT boost (20 Gy prescribed to the applicator surface) or a postoperative EBRT boost (16 Gy in 8 fractions), sequentially after whole-breast radiotherapy, between 2014 and 2019 were retrospectively identified from a prospectively maintained institutional database. Whole-breast irradiation was delivered after IORT using either conventional or moderately hypofractionated schedules according to institutional practice. The primary endpoint was ipsilateral breast tumour recurrence (IBTR). Secondary endpoints included nodal recurrence, distant metastasis, overall survival (OS), and breast cancer-specific survival (BCSS). Time-to-event outcomes were estimated using the Kaplan-Meier method, whereas treatment comparisons were performed using Cox proportional hazards regression with robust sandwich variance estimates clustered by matched pair.

Results: Following 1:1 matching, 400 patients (200 per group) were included. After a median follow-up of 58 months, the cumulative incidence of local recurrence was 3.5% and 2.0%, respectively, with no statistically significant difference between treatment groups (HR 1.80, 95% CI 0.58-5.58; p = 0.312). Likewise, no significant differences were observed for nodal recurrence-free survival (HR 0.98, 95% CI 0.19-5.16; p = 0.980), distant metastasis-free survival (HR 0.92, 95% CI 0.38-2.23; p = 0.859), breast cancer-specific survival (HR 0.79, 95% CI 0.30-2.10; p = 0.634), or overall survival (HR 1.19, 95% CI 0.59-2.40; p = 0.636).

Conclusions: In this matched-pair analysis, an intraoperative low-energy X‑ray boost achieved oncologic outcomes comparable to those of a conventional postoperative EBRT boost in patients undergoing breast-conserving therapy for high-risk early breast cancer. These findings support IORT boost as an effective and well-tolerated alternative that may simplify treatment delivery without compromising long-term oncologic outcomes.

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术中或术后放疗对高危乳腺癌的促进作用：配对分析

目的：高危早期乳腺癌保乳手术后的最佳助推技术仍存在争议。本研究在配对队列中比较了使用低能X射线进行术中放疗（IORT）增强和传统外束放疗（EBRT）增强后的肿瘤预后。方法：从前瞻性维护的机构数据库中回顾性识别2014年至2019年期间接受保乳手术的患者，这些患者在全乳放疗后依次接受前期IORT增强（20 Gy用于涂抹器表面）或术后EBRT增强（16 Gy分8次）。根据机构实践，在IORT后使用常规或中度低分割时间表进行全乳照射。主要终点为同侧乳腺肿瘤复发（IBTR）。次要终点包括淋巴结复发、远处转移、总生存期（OS）和乳腺癌特异性生存期（BCSS）。使用Kaplan-Meier方法估计事件发生时间结果，而使用Cox比例风险回归进行治疗比较，并使用匹配对聚类的稳健三明治方差估计。结果：按1:1匹配，纳入患者400例（每组200例）。中位随访58个月后，累积局部复发率分别为3.5%和2.0%，两组间差异无统计学意义（HR 1.80, 95% CI 0.58-5.58; p = 0.312）。同样，无淋巴结复发生存率（HR 0.98, 95% CI 0.19-5.16; p = 0.980）、无远处转移生存率（HR 0.92, 95% CI 0.38-2.23; p = 0.859）、乳腺癌特异性生存率（HR 0.79, 95% CI 0.30-2.10; p = 0.634）或总生存率（HR 1.19, 95% CI 0.59-2.40; p = 0.636）均无显著差异。结论：在这项配对分析中，术中低能X线增强与传统术后EBRT增强在高危早期乳腺癌保乳治疗患者中获得的肿瘤预后相当。这些发现支持IORT作为一种有效且耐受性良好的替代方法，可以简化治疗过程而不影响长期肿瘤预后。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Strahlentherapie und Onkologie 医学-核医学

CiteScore

5.70

自引率

12.90%

发文量

141

审稿时长

3-8 weeks

期刊介绍： Strahlentherapie und Onkologie, published monthly, is a scientific journal that covers all aspects of oncology with focus on radiooncology, radiation biology and radiation physics. The articles are not only of interest to radiooncologists but to all physicians interested in oncology, to radiation biologists and radiation physicists. The journal publishes original articles, review articles and case studies that are peer-reviewed. It includes scientific short communications as well as a literature review with annotated articles that inform the reader on new developments in the various disciplines concerned and hence allow for a sound overview on the latest results in radiooncology research. Founded in 1912, Strahlentherapie und Onkologie is the oldest oncological journal in the world. Today, contributions are published in English and German. All articles have English summaries and legends. The journal is the official publication of several scientific radiooncological societies and publishes the relevant communications of these societies.