Loap Pierre, Vu Bezin Jeremi, De Marzi Ludovic, Kirova Youlia
Department of Radiation Oncology, Institut Curie, Paris, France.
Strahlenther Onkol. 2025 Feb;201(2):106-114. doi: 10.1007/s00066-024-02240-8. Epub 2024 May 27.
The immune system has been identified as an organ at risk in esophageal and lung cancers. However, the dosimetric impact of radiotherapy on immune system exposure in patients treated for breast cancer has never been studied.
A monocentric retrospective dosimetric study included 163 patients treated at the Institut Curie (Paris, France) between 2010 and 2016 with locoregional helical tomotherapy after conservative surgery or total mastectomy. The effective dose to the immune system (EDIC) was calculated based on diverse dosimetric parameters. The clinical and volumetric determinants of EDIC in adjuvant radiotherapy of breast cancer were analyzed.
The median EDIC for the population was 4.23 Gy, ranging from 1.82 to 6.19 Gy. Right-sided radiotherapy and regional lymph node irradiation were associated with significantly higher EDIC in univariate (4.38 Gy vs. 3.94 Gy, p < 0.01, and 4.27 Gy vs. 3.44 Gy, p < 0.01, respectively) and multivariate analyses (p < 0.01 and p < 0.01). Liver overexposure was the main contributor to EDIC increase in right-sided breast cancer patients (+0.38 Gy [95%CI: +0.30; +0.46]), while the integral total dose increase was the main contributor to EDIC increase in cases of regional node irradiation (+0.63 Gy [95%CI: +0.42; +0.85]).
The EDIC score during adjuvant radiotherapy after breast cancer was statistically significantly higher in the case of right-sided radiotherapy and regional lymph node irradiation. Liver irradiation is the main contributor to immune system exposure in adjuvant irradiation of right-sided breast cancer. Populations in which an association between EDIC and survival would exist have yet to be identified but could potentially include patients treated for triple-negative breast cancer with a poor response to neoadjuvant chemoimmunotherapy.
免疫系统已被确定为食管癌和肺癌中面临风险的器官。然而，放疗对乳腺癌患者免疫系统照射的剂量学影响从未被研究过。
一项单中心回顾性剂量学研究纳入了2010年至2016年间在法国巴黎居里研究所接受保守手术或全乳切除术后局部区域螺旋断层放疗的163例患者。基于多种剂量学参数计算免疫系统的有效剂量（EDIC）。分析了乳腺癌辅助放疗中EDIC的临床和体积决定因素。
该人群的EDIC中位数为4.23 Gy，范围为1.82至6.19 Gy。在单因素分析中，右侧放疗和区域淋巴结照射与显著更高的EDIC相关（分别为4.38 Gy对3.94 Gy，p <0.01，以及4.27 Gy对3.44 Gy，p <0.01），在多因素分析中也是如此（p <0.01和p <0.01）。肝脏过度照射是右侧乳腺癌患者EDIC增加的主要原因（+0.38 Gy [95%CI：+0.30；+0.46]），而积分总剂量增加是区域淋巴结照射病例中EDIC增加的主要原因（+0.63 Gy [95%CI：+0.42；+0.85]）。
在乳腺癌辅助放疗期间，右侧放疗和区域淋巴结照射情况下的EDIC评分在统计学上显著更高。肝脏照射是右侧乳腺癌辅助放疗中免疫系统照射的主要原因。尚未确定EDIC与生存之间存在关联的人群，但可能包括新辅助化疗免疫治疗反应不佳的三阴性乳腺癌患者。
