Volumetric-modulated arc therapy for hippo-campal sparing in whole brain radiotherapy: a new approach for management of brain metastatic cases

Whole brain radiotherapy (WBRT) with two lateral opposed portals has long been considered the standard treatment of choice for patients with brain metastases, because of its wide availability, ease of delivery and its effectiveness for most of the patients. Although this was the main treatment option available and is still widely used, many toxicities, particularly cognitive impairment resulting from WBRT remained a major concern. With the advancement in imaging and treatment delivery techniques, the probability of improved outcomes has increased for many patients. With the improvement in outcomes and the higher expectations of patients regarding better quality of life, the routine use of WBRT has been scrutinized, considering the impact of neuro cognitive functions and quality of life of the patients. The Hippocampus is responsible for memory and cognitive function. Hippocampal sparing whole brain radiotherapy (HS-WBRT) is a technique that aims to reduce the neuro- cognitive side effects of whole brain radiotherapy. In this regard, hippocampus sparing WBRT is an improved technique that aims to spare critical hippocampus region without compromising the tumour control. The aim of this study is limited to planning, feasibility and efficiency of using volumetric modulated arc therapy (VMAT) to spare the hippocampus and all other OARs