Dosimetric characterization of a 2D polycrystalline CVD diamond detector

A bidimensional pixelated dosimeter composed of two polycrystalline Chemical Vapour Deposited diamond films, 2 : 5 x 2 : 5 cm(2) each placed aside, has been manufactured so as to obtain a detector with a 2mm pitch over a total active area of 5 : 0 x 2 : 5 cm(2). We performed the dosimetric characterization of the detector with an Elekta Synergy linear accelerator using a 6 MV photon beam. Uniformity maps, rise and fall times, signal repeatability, dependence on dose rate, linearity with dose and sensitivity show that the device is suitable for dosimetric evaluations in Intensity Modulated Radiation Therapy and Volumetric Modulated Arc Therapy (VMAT) treatments. Then, a first quantitative evaluation of the dose distribution in a lung VMAT treatment plan has been carried out, by comparing data from our device with Treatment Planning Sistem values by means of a T test, with promising results.