Identification of dosimetric risk factors associated to lymphopenia in brain metastases patients with radiotherapy

Abstract Background Radiation-induced lymphopenia (RIL) has been demonstrated in types of solid tumors. This study aimed to assess the association between dosimetric and clinical variables and RIL in patients with brain metastases after brain radiotherapy (RT). Methods The craniofacial bones of 140...

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Main Authors: Sujie Zhang, Yue Wang, Xuan Jiang, Rong He, Xiaojing Zheng, Wenyue Xie
Format: Article
Language:English
Published: BMC 2025-07-01
Series:BMC Cancer
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Online Access:https://doi.org/10.1186/s12885-025-14495-0
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author Sujie Zhang
Yue Wang
Xuan Jiang
Rong He
Xiaojing Zheng
Wenyue Xie
author_facet Sujie Zhang
Yue Wang
Xuan Jiang
Rong He
Xiaojing Zheng
Wenyue Xie
author_sort Sujie Zhang
collection DOAJ
description Abstract Background Radiation-induced lymphopenia (RIL) has been demonstrated in types of solid tumors. This study aimed to assess the association between dosimetric and clinical variables and RIL in patients with brain metastases after brain radiotherapy (RT). Methods The craniofacial bones of 140 patients were retrospectively delineated, and absolute lymphocyte counts (ALC) were collected both prior to RT (pre-RT) and 1 month after completing RT (post-RT). Linear regression analyses were conducted to identify associations between dosimetric variables of the craniofacial bones (V5-V40), mean dose, clinical parameters, and post-RT ALC. Logistic regression analysis was used to evaluate independent predictors of RIL (ALC < 1000 cells/µL). The relationships between dosimetric and clinical variables and overall survival (OS) were analyzed using a Cox regression model. Results After completing RT, ALC decreased in both the whole brain RT (WBRT) and focal RT subgroups (p < 0.05). Linear regression analysis suggested that pre-RT ALC, gross tumor volume (GTV), and the V5 of the craniofacial bones were independent risk factors for the decrease in post-RT ALC. Logistic regression analysis demonstrated that lower pre-RT ALC (OR: 31.969, 95%CI 8.44 to 121.092, p: 0.000) and larger GTV (OR: 2.438, 95%CI 1.037 to 7.819, p: 0.011) were associated with the development of RIL. Notably, no dosimetric variable of the craniofacial bones correlated with RIL. Cox analysis confirmed that pre-RT ALC and V5 of craniofacial bones were associated with OS. Additionally, receiver-operating characteristic (ROC) curve analysis indicated a predictive cutoff value of 702.5 cm³ for GTV in relation to RIL (p < 0.001, AUC = 0.704). Conclusions The consideration of modifiable factors, such as reducing V5 of craniofacial bones, may help preserve lymphocytes and maintain immunologic function, potentially affecting clinical outcomes, especially with a larger GTV.
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spelling doaj-art-be86f2c412ea4d1c8a892f4448f0a8432025-08-20T03:03:37ZengBMCBMC Cancer1471-24072025-07-012511910.1186/s12885-025-14495-0Identification of dosimetric risk factors associated to lymphopenia in brain metastases patients with radiotherapySujie Zhang0Yue Wang1Xuan Jiang2Rong He3Xiaojing Zheng4Wenyue Xie5Department of Oncology, the Second Affiliated Hospital of Chongqing Medical UniversityDepartment of Oncology, the Second Affiliated Hospital of Chongqing Medical UniversityDepartment of Oncology, the Second Affiliated Hospital of Chongqing Medical UniversityDepartment of Oncology, Army Medical Center of PLADepartment of Oncology Hematology, Wushan County People’s HospitalDepartment of Oncology, the Second Affiliated Hospital of Chongqing Medical UniversityAbstract Background Radiation-induced lymphopenia (RIL) has been demonstrated in types of solid tumors. This study aimed to assess the association between dosimetric and clinical variables and RIL in patients with brain metastases after brain radiotherapy (RT). Methods The craniofacial bones of 140 patients were retrospectively delineated, and absolute lymphocyte counts (ALC) were collected both prior to RT (pre-RT) and 1 month after completing RT (post-RT). Linear regression analyses were conducted to identify associations between dosimetric variables of the craniofacial bones (V5-V40), mean dose, clinical parameters, and post-RT ALC. Logistic regression analysis was used to evaluate independent predictors of RIL (ALC < 1000 cells/µL). The relationships between dosimetric and clinical variables and overall survival (OS) were analyzed using a Cox regression model. Results After completing RT, ALC decreased in both the whole brain RT (WBRT) and focal RT subgroups (p < 0.05). Linear regression analysis suggested that pre-RT ALC, gross tumor volume (GTV), and the V5 of the craniofacial bones were independent risk factors for the decrease in post-RT ALC. Logistic regression analysis demonstrated that lower pre-RT ALC (OR: 31.969, 95%CI 8.44 to 121.092, p: 0.000) and larger GTV (OR: 2.438, 95%CI 1.037 to 7.819, p: 0.011) were associated with the development of RIL. Notably, no dosimetric variable of the craniofacial bones correlated with RIL. Cox analysis confirmed that pre-RT ALC and V5 of craniofacial bones were associated with OS. Additionally, receiver-operating characteristic (ROC) curve analysis indicated a predictive cutoff value of 702.5 cm³ for GTV in relation to RIL (p < 0.001, AUC = 0.704). Conclusions The consideration of modifiable factors, such as reducing V5 of craniofacial bones, may help preserve lymphocytes and maintain immunologic function, potentially affecting clinical outcomes, especially with a larger GTV.https://doi.org/10.1186/s12885-025-14495-0Radiation-induced lymphopeniaCraniofacial boneBrain radiotherapyBrain metastasisGross tumor volume
spellingShingle Sujie Zhang
Yue Wang
Xuan Jiang
Rong He
Xiaojing Zheng
Wenyue Xie
Identification of dosimetric risk factors associated to lymphopenia in brain metastases patients with radiotherapy
BMC Cancer
Radiation-induced lymphopenia
Craniofacial bone
Brain radiotherapy
Brain metastasis
Gross tumor volume
title Identification of dosimetric risk factors associated to lymphopenia in brain metastases patients with radiotherapy
title_full Identification of dosimetric risk factors associated to lymphopenia in brain metastases patients with radiotherapy
title_fullStr Identification of dosimetric risk factors associated to lymphopenia in brain metastases patients with radiotherapy
title_full_unstemmed Identification of dosimetric risk factors associated to lymphopenia in brain metastases patients with radiotherapy
title_short Identification of dosimetric risk factors associated to lymphopenia in brain metastases patients with radiotherapy
title_sort identification of dosimetric risk factors associated to lymphopenia in brain metastases patients with radiotherapy
topic Radiation-induced lymphopenia
Craniofacial bone
Brain radiotherapy
Brain metastasis
Gross tumor volume
url https://doi.org/10.1186/s12885-025-14495-0
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