Author: Alan H. Baydush, Sarah Cummings, Jeffrey Michael Fenoli, Christy Hickerson, Lalith Kumaraswamy, Philmo Oh, Sarah B. Wisnoskie 👨🔬
Affiliation: Novant Health Cancer Institute, Novant Health 🌍
Purpose: To develop, validate, and commission a VMAT Total Body Irradiation (TBI) workflow by integrating publicly available resources, commercial solutions, and in-house testing to enhance treatment efficiency and accuracy.
Methods: The commissioning process began with FMEA to establish a desired workflow. After which, we evaluated two publicly available planning scripts for use in Eclipse, VMAT-TBI-CSI and NYU-Langone, with the latter selected for its closer alignment with the desired workflow. Planning goals and parameters were established through a literature review and meetings with institutions that are performing VMAT TBI. To optimize treatment efficiency, commercial solutions were assessed, resulting in the purchase of the Equilibrium rotational couch top (CDR). Physics testing of the couch top included simulation, structure modeling in Eclipse, and attenuation testing. A treatment workflow was developed incorporating setup and guidance with VisionRT. Workflow validation included multiple end-to-end tests, junction verification using MapCheck, portal dosimetry QA, and in-vivo dosimetry utilizing both OSLDs and diodes.
Results: The NYU script provided a successful foundation for planning. Testing of the couch top demonstrated acceptable attenuation and integration into the treatment planning system with no high-density materials present in the device and attenuation testing showing results within 1% difference from baseline between TPS estimated dose and measured dose. VisionRT successfully facilitated accurate patient positioning and monitoring during end-to-end testing. Dosimetric QA measurements confirmed the accuracy of dose delivery, with junction verification and in-vivo dosimetry demonstrating results within clinically acceptable tolerances.
Conclusion: The commissioned VMAT TBI workflow leverages publicly available tools, commercial innovations, and rigorous testing to achieve an efficient and accurate treatment process. The integration of the Equilibrium rotational couch top and VisionRT enhances workflow consistency and patient setup accuracy, while comprehensive QA ensures precise dose delivery. This workflow provides a streamlined, replicable model for VMAT TBI in clinical practice.