Diamond Detectors for Radiotherapy X-Ray Small Beam Dosimetry

Many new X-Ray treatment machines using small and/or non-standard radiation fields, e.g., Tomotherapy, Cyber-knife, and linear accelerators equipped with high-resolution multi-leaf collimators on-board imaging system, have been introduced in the radiotherapy clinical routine within last few years. The introduction of these modalities has led to development high conformal techniques like Intensity Modulated photon Radiation Therapy, Volumetric Arc stereotactic radiotherapy. When techniques, patients are exposed non-uniform dose gradients, time space variation rates, beam energy spectrum. This makes reaching required degree accuracy dosimetry even more demanding. Continuing use standard field procedures detectors fields smaller than 3 × cm 2 , will generate a reduced dosimetry, running risk overshadowing progress made so far applications. These dosimetric issues represent challenge for medical physicists. To choose most appropriate detector different features must be considered. Short- long-term stability, response absorbed rate, no angular dependence, all needed but not sufficient. two sought-after attributes water equivalence highly sensitive (high sensitivity) volumes. Both requirements aim at minimizing perturbations charged particle fluence approaching Charged Particle Equilibrium condition as much possible, while maintaining spatial resolution by reducing averaging effect fields. A compromise between is necessary because dosimeter currently fulfills requirements, diamond properties seem promising could lead marked improvement. Diamonds long used materials dosimeters, natural diamonds were only first applications 80 s. availability reproducible synthetic lower cost compared ones diffusion possible. paper aims review poly single-crystal dosimeters radiotherapy, focusing on their performance under MegaVoltage beams. commercial prototype behaviour described analyzed. Moreover, this report main related results literature, considering growth modalities, electrical contacts, packaging, readout electronics, how do they affect parameters interest such signal linearity, dose-rate reproducibility, rise decay times.