A theoretical investigation on improving the treatment efficiency based on timing characteristics for a proton-and-carbon ion treatment facility / 中华放射肿瘤学杂志

ABSTRACT

Objective:To identify the key factors affecting the time of proton and carbon ion radiotherapy by analyzing the timing characteristics of the accelerator system and to find out potential solutions to enhance treatment efficiency.Methods:The log files for 47 patients with different types of tumors treated with proton beams and carbon ion beams were analyzed. Lung cancer patients were treated with the gating technology. The timing characteristics of beam delivery were analyzed and potential solutions to enhance treatment efficiency were explored.Results:The mean spill time and mean cycle time per iso-energy slice (IES) for proton radiotherapy with beam gating technology were (2.98±1.98) s and (5.71±4.51) s, which were longer than the radiotherapy without using gating technology. The mean total cycle time for treatment without using gating technology was approximately 7 min for both proton and carbon ion beams. The mean total cycle time for lung cancer treatment using gating technology was approximately 15 min.Conclusion:Application of mini-ridge filter or ripple filter to reduce per IES numbers and use of passive breath hold technology to eliminate interruptions during beam delivery in each IES for gating radiotherapy are two feasible approaches to improve treatment efficiency for this specific machine.