Optimal timing and sequence of combining stereotactic radiosurgery with immune checkpoint inhibitors in treating brain metastases: clinical evidence and mechanistic basis

Abstract Recent evidence has shown that immune checkpoint inhibitors (ICIs) are efficacious for treating brain metastases of various primary tumors. However, the immunosuppressive tumor microenvironment and the blood–brain barrier (BBB) or blood-tumor barrier (BTB) essentially restrict the efficacy...

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Bibliographic Details
Main Authors: Wentao Tian, Xianjing Chu, Guilong Tanzhu, Rongrong Zhou
Format: Article
Language:English
Published: BMC 2023-04-01
Series:Journal of Translational Medicine
Subjects:
Online Access:https://doi.org/10.1186/s12967-023-04089-4
Description
Summary:Abstract Recent evidence has shown that immune checkpoint inhibitors (ICIs) are efficacious for treating brain metastases of various primary tumors. However, the immunosuppressive tumor microenvironment and the blood–brain barrier (BBB) or blood-tumor barrier (BTB) essentially restrict the efficacy of ICIs. Stereotactic radiosurgery (SRS) can be a powerful ally to ICIs due to its trait of disrupting the BBB/BTB and increasing the immunogenicity of brain metastases. The combination of SRS + ICI has shown synergy in brain metastases in several retrospective studies. Nevertheless, the optimal schedule for the combination of SRS and ICI in brain metastases is yet to be determined. In this review, we summarized the current clinical and preclinical evidence on the timing and sequence of SRS + ICI to provide insight into the current state of knowledge about this important area in patient care.
ISSN:1479-5876