Kim Seohan, Byun Hwa Kyung, Sung Wonmo
Department of Biomedical Engineering, College of Medicine, the Catholic University of Korea, Seoul, South Korea; Department of Medical Sciences, Graduate School of the Catholic University of Korea, Seoul, South Korea; CMC Institute for Basic Medical Science, the Catholic Medical Center of the Catholic University of Korea, Seoul, South Korea.
Department of Radiation Oncology, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, South Korea.
Int J Radiat Oncol Biol Phys. 2025 Oct 1;123(2):563-571. doi: 10.1016/j.ijrobp.2025.03.082. Epub 2025 Apr 11.
This study aimed to investigate the dose-response pattern of severe radiation-induced lymphopenia (SRIL) in patients with hepatocellular carcinoma (HCC) undergoing radiation therapy (RT). We focused on identifying specific liver regions associated with SRIL development.
We analyzed data from 75 patients with HCC treated with RT. Segment-wise and voxel-based analyses (VBAs) were conducted to investigate the spatial relationship between delivered dose and SRIL occurrence (absolute lymphocyte count [ALC] < 500/µL). Logistic regression was performed for segment-wise analysis, whereas generalized linear models and Mann-Whitney U tests were employed for VBAs. The liver was divided into Couinaud segments, and dose distributions were analyzed at both the segment and voxel levels.
Segment-wise logistic regression revealed that pre-RT ALC (odds ratio [OR], 0.006; P = .002), liver segments 1 (OR, 1.228; P = .048), and 7 (OR, 1.314; P = .016) were statistically associated with SRIL occurrence. VBAs demonstrated heterogeneous dose-response patterns across the liver, with segment 1 consistently showing the strongest association with SRIL across different statistical methods. Segment 1 contained the highest proportion of statistically significant voxels (94%) in relation to SRIL occurrence among all liver segments.
This study revealed an inhomogeneous dose-response pattern regarding SRIL manifestation in the liver. Our results suggest that certain regions within a single organ may require rigorous dosimetric constraints to mitigate SRIL.
本研究旨在调查接受放射治疗（RT）的肝细胞癌（HCC）患者中重度辐射诱导淋巴细胞减少症（SRIL）的剂量反应模式。我们着重于识别与SRIL发生相关的特定肝区。
我们分析了75例接受RT治疗的HCC患者的数据。进行了基于节段和基于体素的分析（VBA），以研究所给予的剂量与SRIL发生（绝对淋巴细胞计数[ALC]<500/μL）之间的空间关系。对基于节段的分析进行逻辑回归，而对VBA采用广义线性模型和曼-惠特尼U检验。肝脏被分为Couinaud肝段，并在节段和体素水平分析剂量分布。
基于节段的逻辑回归显示，放疗前ALC（比值比[OR]，0.006；P = 0.002）、肝段1（OR，1.228；P = 0.048）和肝段7（OR，1.314；P = 0.016）与SRIL发生在统计学上相关。VBA显示肝脏各部位的剂量反应模式存在异质性，在不同统计方法中，肝段1始终与SRIL表现出最强的相关性。在所有肝段中，肝段1与SRIL发生相关的具有统计学意义的体素比例最高（94%）。
本研究揭示了肝脏中SRIL表现的不均匀剂量反应模式。我们的结果表明，单个器官内的某些区域可能需要严格的剂量学限制以减轻SRIL。
