The Commissioning and Validation of Gpumcd for an Elekta Versa HD Linear Accelerator In the Elekta One Treatment Planning System
Abstract
Purpose
GPUMCD, a GPU-accelerated Monte Carlo dose calculation algorithm, was recently released for clinical implementation in the Elekta One Treatment Planning System (v6.2.3, EOP) for c-arm Elekta linear accelerators (linac). The purpose of this work was to validate and commission this algorithm for clinical use.
Methods
Beam models were generated for all photon energies of a VersaHD linac (6X, 6FFF, 10X, 10FFF, 18X) from open field water tank data measurements acquired at an SSD of 90cm. A validated version of the Monaco Commissioning Utility was used to compare the generated percent depth dose (PDD) profiles and lateral profiles against measurements. An adapted MPPG 5.b. methodology was used to verify the clinical feasibility of using this algorithm in both homogeneous and heterogeneous media using the ArcCheck, solid water, the CIRS ZEUS phantom, and the IROC HN and spine phantoms.
Results
An average agreement of 98.4±2.3% across all energies was observed using a local 2% dose difference (DD) for fields greater than 5x5 cm2 in the high dose region between measured and calculated PDDs and beam profiles. For all fields, an agreement of 99.9±0.5% was found using a 2% DD and 2 mm distance-to-agreement (DTA) gamma criteria with a 5% dose threshold. All adapted MPPG 5.b. testing was within the suggested tolerance limit and all plan measurements passed the recommended gamma criteria. Point dose and heterogeneity measurements agreed within 3%. A 93% calculation time reduction was observed when using GPUMCD compared to XVMC, for open fields, using the same hardware.
Conclusion
The GPUMCD algorithm in EOP was successfully commissioned for clinical use with the VersaHD linac for all photon energies.