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[For the plans evaluated] overall deviations were between -1.7% and +1.8% for the commissioned model, a tolerance level of 3% and an action level of 5% was
implemented clinically. Individual beams in a clinical plan with a deviation greater than ~8% are manually reviewed.
Authors
Stephen A. Graves, Jeffrey E. Snyder, Amanda Boczkowski, Joël St-Aubin, Dongxu Wang, Sridhar Yaddanapudi, Daniel E. Hyer
Journal of applied clinical medical physics
Published 13. November 2019
Abstract
Recent availability of MRI-guided linear accelerators has introduced a number of clinical challenges, particularly in the context of online plan adaptation. Paramount among these is verification of plan quality prior to patient treatment. Currently, there are no commercial products available for monitor unit verification that fully support the newly FDA cleared Elekta Unity 1.5 T MRI-linac. In this work, we investigate the accuracy and precision of RadCalc for this purpose, which is a software package that uses a Clarkson integration algorithm for point dose calculation. To this end, 18 IMRT patient plans (186 individual beams) were created and used for RadCalc point dose calculations. In comparison with the primary treatment planning system (Monaco), mean point dose deviations of 0.0 ± 1.0% (n = 18) and 1.7 ± 12.4% (n = 186) were obtained on a per-plan and per-beam basis, respectively. The dose plane comparison functionality within RadCalc was found to be highly inaccurate, however, modest improvements could be made by artificially shifting jaws and multi leaf collimator positions to account for the dosimetric shift due to the magnetic field (67.3% vs 96.5% mean 5%/5 mm gamma pass rate).
Here you can find the paper in the journal of applied clinical medical physics