Application of octavius 4D system in volumetric modulated arc therapy dose verification / 中华放射肿瘤学杂志

ABSTRACT

Objective To study the feasibility of dose verification with Octavius 4D system in volumetric modulated arc therapy (VMAT).Methods Twenty patients were treated with the VMAT.Their treatment plans were performes and then acquired the measured data with the Octavius 4D system.In addition,the treatment plans are used in the CT phantom for Octavius 4D system,and acquire the simulated data.We use the γ pass rate to analysis the measured and simulated results for the conditionsthe dose deviations are 2％3％5％,the displacement deviations are 2 mm/3 mm/5 mm and the thresholds are 5％ 10％,and got the Gamma pass rate and fitness of profile curve.Results The distributions of measured and simulated dose are matched well,and the fitness of profile curve are also matched well.The averaged Gamma pass rate is 97.78％ in the case 3 mm 3％ 10％.Conclusions Octavius 4D system can meet the dose verification for VMAT treatment.The measured plane is always following the rotating frame and perpendicular to the beam.