Safety and Feasibility of Hippocampal Sparing Cranial Radiation in Acute Lymphoblastic Leukaemia Patients- A prospective study

Introduction: Acute lymphoblastic leukemia (ALL) constitutes a significant portion of pediatric malignancies, with CNS relapse posing a considerable threat to patient outcomes. While prophylactic cranial irradiation (PCI) has been utilized to mitigate CNS relapse, it is associated with neurocognitive side effects. This study explores the feasibility and safety of using Volumetric Arc Therapy (VMAT) with hippocampal sparing during cranial radiation therapy for ALL patients, aiming to reduce these side effects. Methods: This prospective observational study included pediatric and young adult ALL patients in remission. Hippocampal sparing was achieved using VMAT, and neurocognitive assessments were performed at baseline, 6 months, 1 year, and, to a limited extent, 4 years post-treatment. Results: VMAT enabled precise hippocampal sparing with minimal dose impact on the hippocampus. There were no observed brain relapses among the patients in this study. Neurocognitive assessments demonstrated an maintained IQ scores over time, with no decline in neurocognitive funtions Conclusion: This study highlights the potential of VMAT with hippocampal sparing as a promising approach to cranial radiation therapy for ALL patients in reducing the risk of neurocognitive side effects. The absence of brain relapses is encouraging, although larger studies are needed for conclusive evidence. The preservation of neurocognitive function may be attributed to the reduced radiation dose to the hippocampal region.