Synthetic single crystal diamond dosimeters for conformal radiation therapy application

A synthetic single crystal diamond based dosimeter in a p-type/intrinsic/metal structure, operating in photovoltaic regime, is proposed for application in highly conformed radiotherapy dosimetry. The device was characterized by using 6 and 10 MV Bremsstrahlung X-ray beams and electron beams from 6 MeV up to 18 MeV, obtained by a CLINAC DHX Varian accelerator. All measurements were performed in a water phantom and commercial ionization chambers were used for calibration and comparison. Results showed a very good agreement of the diamond device response, as compared with the reference dosimeters, fast response times and high spatial resolution. One of such diamond dosimeters was then tested using a real Intensity Modulated Radiation Therapy (IMRT) prostate cancer treatment plan and its performance was compared with the ones from ionization chambers and a 2D diode array. The obtained results clearly assess the suitability of synthetic single crystal diamond for dose measurements in highly conformed radiotherapy and particularly in IMRT applications.