Cranial radiation therapy with hippocampus avoidance in lung cancer treatment: systematic review and meta-analysis

Yue Zheng; Liting You; Baijie Feng; Min Tang; Feifei Na

doi:10.3389/fonc.2023.1268754

Cranial radiation therapy with hippocampus avoidance in lung cancer treatment: systematic review and meta-analysis

Front Oncol. 2023 Oct 23:13:1268754. doi: 10.3389/fonc.2023.1268754. eCollection 2023.

Authors

Yue Zheng^#¹, Liting You^#², Baijie Feng³, Min Tang¹, Feifei Na¹

Affiliations

¹ Division of Thoracic Tumor Multimodality Treatment and Department of Radiation Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
² Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
³ West China School of Medicine, Sichuan University, Chengdu, Sichuan, China.

^# Contributed equally.

Abstract

Background: The role of cranial radiation therapy with hippocampus avoidance (HA-CRT) in neurocognitive function (NCF), brain metastasis (BM), and overall survival (OS) in lung cancer remains unclear.

Methods: A meta-analysis was conducted to evaluate the impact of HA-CRT in lung cancer. Data from studies on hippocampal-avoidance prophylactic cranial irradiation (HA-PCI) and whole brain radiotherapy (HA-WBRT) were pooled.

Results: A total of 14 studies, including 5 randomized controlled trials, were included. The focus of NCF was mainly via the Hopkins Verbal Learning Test-Revised or the Free and Cued Selective Reminding Test. At 6 months post-radiotherapy, the pooled proportion of participants with decline in the performance of total recall, delayed recall, and discrimination in neurocognitive tests were 0.22 (95% CI 0.15, 0.29), 0.20 (95% CI 0.13, 0.27), and 0.14 (95% CI 0.05, 0.24) respectively. After 12 months, the proportion were 0.16 (95% CI 0.08, 0.23), 0.10 (95% CI 0.04, 0.16), and 0.04 (95% CI 0, 0.09) respectively. For HA zone relapse, the RR of HA-CRT versus CRT was 2.72 (95% CI 0.53, 13.87), and for 2-year BM, it was 1.20 (95% CI 0.82, 1.75). Regarding HA-PCI in SCLC, the 1-year BM rate was 0.12 (95% CI 0.07, 0.17), and the 2-year BM rate was 0.20 (95% CI 0.16, 0.25). For HA-WBRT in NSCLC with BM, the 2-year intracranial progression rate was 0.38 (95% CI 0.13, 0.62). There was no significant difference in OS between HA-CRT and CRT.

Conclusions: HA-CRT appears to be safe in lung cancer, but it may not outperform conventional CRT. Larger RCTs comparing HA-CRT and CRT are warranted.

Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022360890, identifier CRD42022360890.

Keywords: hippocampus avoidance; lung cancer; neurocognitive function; prophylactic cranial irradiation; whole brain radiotherapy.

Publication types

Systematic Review

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported by Department of Science and Technology of Sichuan Province [2022YFS0205].