title: A clinical database to assess action levels and tolerances for the ongoing use of Mobius3D.
abstract: In radiation therapy, calculation of dose within the patient contains inherent uncertainties, inaccuracies, limitations, and the potential for random error. Thus, point dose-independent verification of such calculations is a well-established process, with published data to support the setting of both action levels and tolerances. Mobius3D takes this process one step further with a full independent calculation of patient dose and comparisons of clinical parameters such as mean target dose and voxel-by-voxel gamma analysis. There is currently no published data to directly inform tolerance levels for such parameters, and therefore this work presents a database of 1000 Mobius3D results to fill this gap. The data are tested for normality using a normal probability plot and found to fit this distribution for three sub groups of data; Eclipse, iPlan and the treatment site Lung. The mean (μ) and standard deviation (σ) of these sub groups is used to set action levels and tolerances at μ ± 2σ and μ ± 3σ, respectively. A global (3%, 3 mm) gamma tolerance is set at 88.5%. The mean target dose tolerance for Eclipse data is the narrowest at ± 3%, whilst iPlan and Lung have a range of -5.0 to 2.2% and -1.8 to 5.0%, respectively. With these limits in place, future results failing the action level or tolerance will fall within the worst 5% and 1% of historical results and an informed decision can be made regarding remedial action prior to treatment.
authors.affiliation: Epworth Radiation Oncology Research Centre, Epworth HealthCare, Melbourne, VIC, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Jolly
authors.affiliation: Epworth Radiation Oncology Research Centre, Epworth HealthCare, Melbourne, VIC, Australia.
authors.forename: Leon
authors.initials: L
authors.lastname: Dunn
authors.affiliation: Epworth Radiation Oncology Research Centre, Epworth HealthCare, Melbourne, VIC, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Kenny
mesh_terms: D000465:Algorithms; D002985:Clinical Protocols; D016208:Databases, Factual; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy*; D009010:Monte Carlo Method; D011786:Quality Control; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods / Q000592:standards*; D050397:Radiotherapy, Intensity-Modulated / Q000592:standards*
keywords: Mobius3D; action level; database; independent verification; tolerances