Comparative Study Evaluating Cognitive Functions in Patients Receiving Conventional Whole Brain Radiotherapy vs Hippocampal Avoidance Whole Brain Radiotherapy

Abstract

Background: Whole brain radiotherapy is the treatment of choice for patients with brain metastases. However, neurocognitive functions decline due to impaired hippocampal neurogenesis might occur thereafter. It is hypothesized that conformal hippocampal avoidance during the course of WBRT might provide meaningful neurocognitive functions preservation. Our study aims to demonstrate the impact of delivering HA‑WBRT on NCF changes in patients receiving WBRT. Methods: fifty patients who were referred for cranial irradiation were enrolled in the study. Before the HA‑WBRT course and randomly assigned to two equal groups, the first group will receive conventional whole brain palliative radiotherapy and the second group will receive hippocampal sparing whole brain radiotherapy, assigned to 30 Gy over 10 fractions over two weeks, all participants should receive baseline neurocognitive assessment, including memory, executive functions, and psychomotor speed,the primary endpoint was delayed recall, as determined by the change/decline in Hopkins Verbal Learning Test (HVLT-R) and The One Card Learning Test (OCLT) from the baseline assessment to 4 months after the start of HA‑WBRT. Results: Regarding neurocognitive outcomes, no statistically significant differences were found between various NCF scores obtained at baseline and at post‑radiotherapy intervals, in immediate verbal memory and non‑verbal memory, except for delayed recall memory on HVLT-R Hopkins Verbal Learning Test -Revised for delayed recall Learning, p =0.008. Conclusions: Functional preservation by hippocampal sparing during WBRT could largely be achieved in this study, which also suggests that HA‑WBRT should be a feasible technique preserving neurocognitive functions while maintaining intracranial control.