Development of a standalone delivery sequence model for proton arc therapy

Abstract Background Spot‐scanning proton arc (SPArc) has been drawing significant interests in recent years because of its capability of continuous proton irradiation during the gantry rotation. Previous studies demonstrated SPArc plans were delivered on a prototype of the DynamicARC solution, IBA ProteusONE. Purpose We built a novel delivery sequence model through an independent experimental approach: the first SPArc delivery sequence model (DSM SPArc ). Based on the model, we investigated SPArc treatment efficiency improvement in the routine proton clinical operation. Methods SPArc test plans were generated and delivered on a prototype of the DynamicARC solution, IBA ProteusONE. An independent gantry inclinometer and the machine logfiles were used to derive the DSM SPArc. Seventeen SPArc plans were used to validate the model's accuracy independently. Two random clinical operation dates (6th January and 22nd March, 2021) from a single‐room proton therapy center (PTC) were selected to quantitatively assess the improvement of treatment efficiency compared to the IMPT. Results The difference between the logfile and DSM SPArc is about 3.2 ± 4.8%. SPArc reduced 58.1% of the average treatment delivery time per patient compared to IMPT ( p < 0.01). Daily treatment throughput could be increased by 30% using SPArc using a single‐room proton therapy system. Conclusions The first model of dynamic arc therapy is established in this study through an independent experimental approach using logfiles and measurements which allows clinical users and investigators to simulate the dynamic treatment delivery and assess the daily treatment throughput improvement.