Berg Lovisa, Sporre Jeanette, Kjellén Elisabeth, Ceberg Sofie, Wieslander Elinore, Alkner Sara
Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden; Department of Oncology, Institute of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden.
Clinic of Oncology, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden.
Acta Oncol. 2025 Jul 30;64:989-996. doi: 10.2340/1651-226X.2025.43716.
Indications for radiotherapy (RT) of the internal mammary nodes (IMN) in early breast cancer vary between countries. While studies indicate benefits, IMN RT increases the dose to the heart and lungs, and the risk-benefit ratio of this treatment is debated. This study investigates how IMN RT affects dose to organs at risk (OAR) and pneumonitis incidence in a clinical setting.
This retrospective study includes breast cancer patients receiving adjuvant locoregional RT with and without IMN included in the target volume at Skåne University Hospital, Sweden, from 2018 to 2021. Treatment plans followed national dose-volume criteria, prioritizing lung and heart over IMN coverage. A total of 247 treatment plans for locoregional RT with IMN were compared to 397 without. Dose to OAR, IMN coverage and pneumonitis incidence were investigated.
The mean ipsilateral lung dose increased by 2.7 Gy with IMN RT (p < 0.001), and the mean heart dose (left-sided treatment) by 0.5 Gy (p < 0.001). Both irradiated and treated volume in relation to planning target volume (PTV) increased with ~20% (p < 0.001). Desired IMN coverage was achieved in 76% of the plans, with lung dose exceeding recommended constraints as the primary reason for decreased target coverage in the remaining plans. Of the 220 patients with follow-up of ≥6 months, 2 (0.9%) were diagnosed with pneumonitis grade 2.
Introduction of IMN RT primarily resulted in an increased lung dose. However, rate of symptomatic pneumonitis was low. Most patients achieved desired IMN coverage using 3D-CRT, with lung dose being the limiting factor.
早期乳腺癌内乳淋巴结（IMN）放疗（RT）的适应症在不同国家有所不同。虽然研究表明其有益处，但IMN放疗会增加心脏和肺部的剂量，这种治疗的风险效益比存在争议。本研究调查了在临床环境中IMN放疗如何影响危及器官（OAR）的剂量和肺炎发病率。
这项回顾性研究纳入了2018年至2021年在瑞典斯科讷大学医院接受辅助局部区域放疗的乳腺癌患者，放疗靶区包括或不包括IMN。治疗计划遵循国家剂量体积标准，优先考虑肺部和心脏而非IMN的覆盖范围。将总共247例有IMN的局部区域放疗治疗计划与397例无IMN的治疗计划进行比较。研究了OAR的剂量、IMN的覆盖范围和肺炎发病率。
IMN放疗使同侧肺平均剂量增加2.7 Gy（p < 0.001），心脏平均剂量（左侧治疗）增加0.5 Gy（p < 0.001）。与计划靶体积（PTV）相关的照射体积和治疗体积均增加约20%（p < 0.001）。76%的计划实现了所需的IMN覆盖，其余计划中靶区覆盖减少的主要原因是肺剂量超过推荐限制。在220例随访≥6个月的患者中，2例（0.9%）被诊断为2级肺炎。
IMN放疗的引入主要导致肺剂量增加。然而，有症状肺炎的发生率较低。大多数患者使用三维适形放疗（3D-CRT）实现了所需的IMN覆盖，肺剂量是限制因素。
