A Method to Enhance the Spatial Resolution of the Two-dimensional Detector Arrays for the Precise Dose Assessment of Intensity Modulated Radiation Therapy

Abstract

Two-dimensional (2D) detector arrays are widely used in the patient-specific quality assurance of intensity modulated radiation therapy (IMRT). One of the disadvantages of the 2D detector arrays is the low spatial resolution. We proposed a new method to enhance the spatial resolution of the 2D detector arrays. We showed that this method also reduced the volume effect of a detector element. To demonstrate the method we evaluated one field of an IMRT verification plan with the 2D ion chamber array. An open field was measured and its penumbra width was evaluated to show the reduction of the volume effect of the detector. Using the proposed method, the distance between measurement points was reduced from 7.62 mm to 6.00 mm and the penumbral width was also reduced.