Hippocampal sparing in whole-brain radiotherapy for brain metastases: controversy, technology and the future

Rui Liu; GuanZhong Gong; KangNing Meng; ShanShan Du; Yong Yin

doi:10.3389/fonc.2024.1342669

Hippocampal sparing in whole-brain radiotherapy for brain metastases: controversy, technology and the future

Front Oncol. 2024 Jan 24:14:1342669. doi: 10.3389/fonc.2024.1342669. eCollection 2024.

Authors

Rui Liu^{1

2}, GuanZhong Gong², KangNing Meng^{1

2}, ShanShan Du², Yong Yin²

Affiliations

¹ Department of Graduate, Shandong First Medical University, Shandong Academy of Medical Sciences, Jinan, China.
² Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China.

Abstract

Whole-brain radiotherapy (WBRT) plays an irreplaceable role in the treatment of brain metastases (BMs), but cognitive decline after WBRT seriously affects patients' quality of life. The development of cognitive dysfunction is closely related to hippocampal injury, but standardized criteria for predicting hippocampal injury and dose limits for hippocampal protection have not yet been developed. This review systematically reviews the clinical efficacy of hippocampal avoidance - WBRT (HA-WBRT), the controversy over dose limits, common methods and characteristics of hippocampal imaging and segmentation, differences in hippocampal protection by common radiotherapy (RT) techniques, and the application of artificial intelligence (AI) and radiomic techniques for hippocampal protection. In the future, the application of new techniques and methods can improve the consistency of hippocampal dose limit determination and the prediction of the occurrence of cognitive dysfunction in WBRT patients, avoiding the occurrence of cognitive dysfunction in patients and thus benefiting more patients with BMs.

Keywords: brain metastases; contour; dose limits; hippocampus avoidance; new radiotherapy techniques; whole brain radiotherapy.

Publication types

Review

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported in part by the Taishan Scholars Project of Shandong Province (Grant No. ts201712098).