The Effect of Hippocampal Avoidance Whole Brain Radiotherapy on the Preservation of Long-Term Neurocognitive Function in Non-Small Cell Lung Cancer Patients With Brain Metastasis

Abstract

Whole-brain radiotherapy (WBRT) is the mainstay of therapy in treating cancer patients with brain metastases, but unfortunately, it might also lead to decline in neurocognitive function. This study aims to investigate the preservation of long-term neurocognitive function in patients after hippocampal avoidance whole-brain radiotherapy (HA-WBRT). Retrospectively, 47 patients diagnosed with brain metastases of non-small cell lung cancer (NSCLC) between 2015-01-01 and 2017-12-31 at the Department of Oncology, XXX Hospital were selected and divided into 2 groups. Group A (n = 27) received HA-WBRT, whereas group B (n = 20) received WBRT. Neurocognitive function was analyzed at baseline and at 3, 6, 9, 12 and 24 months after radiotherapy, using Mine-Mental State Examination (MMSE) scales and Montreal Cognitive Assessment (MoCA) scales. The OS, PFS and tumor recurrence sites were also analyzed. When evaluated at 12 and 24 months after radiotherapy, the cognitive function scores of the hippocampal avoidance group were significantly higher than those of the non-hippocampal avoidance group ( P < 0.001). In terms of patient survival, there was no significant difference in OS ( P = 0.2) and PFS (P = 0.18) between these 2 groups. Fourteen patients in group A and 12 patients in group B had brain tumor recurrence after radiation, only one patient in group A occurred within 5 mm from the edge of the hippocampus ( P > 0.05). In conclusion, HA-WBRT might have a protective effect on long-term neurocognitive function and did not affect patient survival.

Partial hippocampal avoidance whole brain radiotherapy in a patient with metastatic infiltration of the left hippocampus

“…The study observed no differences in progression free survival (PFS), overall survival (OS), or hippocampal relapse rate between groups 7. Some studies have observed significant differences in NCF between groups up to 24 months post-RT 21 22. Our patient experienced a 10% drop in HVLT-DR score at 2 months and a complete recovery at four and 6 months.…”

Evaluation of potential predictive biomarkers for defining brain radiotherapy efficacy in NSCLC patients with brain me-tastases: A case report and review of literature

“…Persistent toxicity includes impaired physiological function of hippocampus, ataxia, insomnia, dysphasia and dementia [64,74,[76][77][78][79]. WBRT toxicity can be reduced by exclusion of selective brain areas such as the hippocampus, leading to an improvement of neurocognitive function, functional autonomy and quality of life [64,75,80]. In the case we have described, WBRT included the hippocampus area, severe toxicities were reported, and no clinical benefit was achieved.…”

Hippocampal region avoidance in whole brain radiotherapy in brain metastases: For all or for some? A real-world feasibility report

“…Indeed, there is a rising interest in published studies reporting fewer neurological impairments after HS-WBRT, compared to conventional WBRT, justifying the increased use of this modern RT technique. [32][33][34][35] Another limitation is represented by the fact that reported clinical outcome results come from a wide and heterogeneous series of negatively selected patients with several lines of previous treatments or synchronous polymetastatic disease. No calculation of the total number of brain metastases and volume was performed, representing an additional limitation of the study.…”