1146 - A Single Automated VMAT Planning Framework for TBI, CSI and TMLI: Streamlining Workflow and Enhancing Plan Quality
Presenter(s)
E. A. Simiele1,2, I. O. Romero3, C. Hui4, M. S. Binkley2, I. C. Gibbs2, R. T. Hoppe2, S. M. Hiniker2, and N. Kovalchuk5; 1University of Alabama Birmingham School of Medicine, Birmingham, AL, 2Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, 3Stanford University School of Medicine, Palo Alto, CA, 4University of California - Irvine, Irvine, CA, 5Department of Radiation Oncology, Stanford University, Stanford, CA
Purpose/Objective(s): We report on a unified, fully automated, and open-source VMAT planning framework targeting three distinct yet complex treatment modalities: total body irradiation (VMAT-TBI), craniospinal irradiation (VMAT-CSI), and total marrow and lymphoid irradiation (VMAT-TMLI). Our overarching goal was to reduce planning time, improve plan consistency, and maintain or enhance plan quality for each modality. The auto-planning tool is publicly shared to benefit the radiation oncology community around the world.
Materials/Methods: An integrated scripting tool was developed within the Varian treatment planning system Scripting Application Programming Interface to automate VMAT-TBI, VMAT-CSI, and VMAT-TMLI. To test the auto-plan quality compared to manual plans, 35 patients were selected (10 patients for VMAT-TBI, 20 patients for VMAT-CSI, and 5 patients for VMAT-TMLI). Plans were compared using target and organ-at-risk (OAR) DVH metrics and evaluated using blinded physicians’ reviews. Efficiency gains in using the auto-planning script were also estimated compared to manual planning for each technique. Following validation, the auto-planning tool was clinically adopted and the VMAT-TBI auto-planning functionality was incorporated into the COG ASCT2031 multi-institutional clinical trial.
Results: For VMAT-TBI, auto-plans matched or surpassed manual plans in PTV coverage, global Dmax, and kidney doses, with a notable reduction in mean lung dose (5.4%±6.4%, p<0.05). Planning time decreased from 2–3 days to approximately 3–5 hours, and 77% of auto-plans were deemed equivalent or superior to the manual plans by reviewing physicians.
For VMAT-CSI, auto-plans offered statistically significant reductions in body V50% and mean doses to the parotids, submandibular glands, and thyroid, with 88.3% of auto-plans rated as equivalent or superior to their manual plan counterparts. Total planning time decreased from ~5–6 hours to 1–2 hours. For VMAT-TMLI, auto-plans provided target coverage and heterogeneity equivalent to manual plans, with significant improvements in OAR sparing for the kidneys, heart, and eyes. The variance in achieved DVH metrics was consistently lower with the auto-plans, and the average planning time decreased from 2–3 days to ~6 hours.Conclusion: A single automated scripting framework can effectively plan VMAT-TBI, VMAT-CSI, and VMAT-TMLI, substantially reducing planning time while maintaining or improving plan quality compared to manual planning. Streamlined approach enhances consistency, alleviates clinical workload, and supports broader patient access to advanced radiotherapy techniques. VMAT-TBI and VMAT-CSI functionalities of the developed auto-planning script have been implemented clinically, treating more than 175 VMAT-TBI patients and 25 VMAT-CSI patients to date. All developed software has been made open-source and is actively maintained, enabling other institutions to integrate and adapt these scripts into their own clinical practice.