The feasibility and benefits of using volumetric arc therapy in patients with brain metastases: a systematic review

Radiotherapy management of patients with brain metastases most commonly involve a whole-brain radiation therapy (WBRT) regime, as well as newer techniques such as stereotactic radiosurgery (SRS) and intensity modulated radiotherapy (IMRT). The long treatment times incurred by these techniques indicates the need for a novel technique that has shorter treatment times, whilst still producing highly conformal treatment with the potential to deliver escalated doses to the target area. Volumetric modulated arc therapy (VMAT) is a dynamic, highly conformal technique that may deliver high doses of radiation through a single gantry arc and reduce overall treatment times. The aim of this systematic review is to determine the feasibility and benefits of VMAT treatment in regard to overall survival rates and local control in patients with brain metastases, in comparison with patients treated with WBRT, SRS and IMRT. Methods: A search of the literature identified 23 articles for the purpose of this review. Articles were included on the basis they were human based studies, with sample sizes of more than five patients who were receiving treatment for 1-10 metastatic brain lesions. Results: VMAT was found to be highly conformal, have a reduced treatment delivery time and incurred no significant toxicities in comparison with WBRT, SRS and IMRT. Conclusion: Compared to other treatment techniques, VMAT proved to have fewer toxicities than conventional WBRT, shorter treatment times than SRS and similar dose distributions to IMRT plans. Future prospective studies are needed to accurately assess the prognostic benefits of VMAT as well as the occurrence of late toxicities.