Demonstration of motion-compensated volumetric modulated arc radiotherapy on an MR-linac

• DOI: 10.1016/j.phro.2025.100729
• Publication Date: 2025-02-16T00:02:33Z
• Authors: Pim T.S. Borman; Prescilla Uijtewaal; Jeffrey Snyder; Bryan Allen; Caiden K. Atienza; Peter Woodhead; Daniel E. Hyer; Bas W. Raaymakers; Martin F. Fast
• Keywords: Medical physics. Medical radiology. Nuclear medicine; R895-920; Neoplasms. Tumors. Oncology. Including cancer and carcinogens; VMAT; MLC tracking; Lung cancer; MR-linac; RC254-282

Intensity-modulated radiotherapy (IMRT) in combination with magnetic resonance imaging (MRI)-guided gated delivery represents the latest development in the treatment of abdominothoracic tumours on MR-linac. In contrast, volumetric-modulated arc therapy (VMAT) is typically used on conventional linacs due to its superior delivery efficiency and speed. Non-inferior VMAT plans were created in a research treatment planning system for eight lung cancer patients previously treated on an MR-linac. VMAT plans were delivered on a moving dosimeter using respiratory multi-leaf collimator (MLC) tracking. VMAT with MLC tracking achieved an average 2%/2 mm local gamma pass rate of 93% relative to planned dose with a delivery efficiency of 83%.