BLUE RIBBON POSTER THERAPY: First Clinical Monte Carlo TPS for Electron Flash Radiotherapy: Gmv Radiance Deployment Via Comprehensive Applicator-Specific Phase Space Validation
Abstract
Purpose
To validate and deploy a complete applicator-specific phase space file library for the GMV Radiance treatment planning system, establishing the first clinically ready Monte Carlo-based treatment planning system (TPS) for electron FLASH radiotherapy.
Methods
Applicator-specific PHSP files were generated at the exit plane for all Mobetron UHDR aperture and insert configurations (short cone and long cone, 2.5-10 cm) using a commissioned 9 MeV Monte Carlo model. The GMV Radiance TPS architecture requires applicator-exit boundary conditions for dose calculations, necessitating comprehensive validation across all clinical configurations. Dose calculations were validated against both traditional linac-exit PHSP files and experimental measurements for percent depth dose and lateral dose profiles. Statistical validation included gamma analysis (3%/3mm criteria) and quantitative dosimetric parameter comparisons to establish clinical acceptance.
Results
All applicator-exit PHSP files demonstrated clinical-grade agreement with experimental measurements, meeting GMV Radiance deployment requirements. Gamma analysis revealed 100% pass rates for all A6 configurations (2.5-6.0 cm) and mean pass rates of 99.6% for PDDs and 96.9% for profiles across A10 series (6.0-10.0 cm), all exceeding 95% clinical acceptance. Mean dosimetric parameter differences ranged from -4.3% to 6.3% for PDDs and -2.0% to 4.2% for profiles. With complete PHSP library validation, the GMV Radiance TPS is now commissioned for clinical FLASH treatment planning, providing 30-50% reductions in dose calculation time compared to linac-exit boundary simulations while maintaining dosimetric accuracy.
Conclusion
This work establishes the first validated, deployment-ready treatment planning system for electron FLASH radiotherapy. The comprehensive applicator-specific PHSP library meets GMV Radiance architectural requirements and clinical accuracy standards across all Mobetron configurations, enabling immediate clinical implementation of Monte Carlo-based FLASH treatment planning with improved computational efficiency.