Validation of Log File-Based Patient 3D Dose Calculation with Arccheck 3DVH Reconstruction for Single-Isocenter Multiple-Target Brain Plans
Abstract
Purpose
To validate plan-delivery log file-based 3D dose calculations with ArcCHECK (AC) 3DVH reconstruction for single-isocenter multiple-target (SIMT) brain plans
Methods
Twelve SIMT brain plans with a total of 61 targets were selected for the study. All plans were created in Eclipse Treatment Planning System (TPS) (v. 16.1) with non-coplanar VMAT photon beams calculated with AcurosXB (v. 16.1.2) algorithm. They were delivered on a TrueBeam STx linac to produce the corresponding log files (LFs). The patient plan and the corresponding LF were imported to myQA iON system (IBA Dosimetry Gmbh) for 3D dose calculations using a Monte Carlo dose calculation algorithm. The results provided DVH comparison for each target. Patient QA plans were created on ArcCHECK phantom and 3D dose was reconstructed on patient anatomy in the 3DVH software (v. 3.3.1). The mean dose of each target was compared between the LF vs TPS, AC-3DVH vs TPS, and LF vs AC-3DVH.
Results
The mean doses of all 61 targets for the TPS, LF, and AC-3DVH were 28.20 Gy, 27.64 Gy, and 28.95 Gy. The mean percentage difference for the LF vs TPS, AC-3DVH vs TPS, and LF vs AC-3DVH was -1.99%, 2.57%, and -4.55%, respectively. The matched pairs test values among three comparisons were all much less than 0.05, suggesting statistically significant correlation between the calculated and the measured results.
Conclusion
The LF-based calculation and the AC-3DVH reconstructed results showed good agreement with the TPS results and were within 3.0%. The agreement between the LF-based calculations and the AC-3DVH reconstructed results was within 5.0% and acceptable, considering the uncertainties of the measurement and 3DVH algorithm. These results validated that the LF-based method has sufficient accuracy for 3D dose verification of SIMT brain plans.