Assessment of basic physical and dosimetric parameters of synthetic single-crystal diamond detector and its use in Leksell Gamma Knife and CyberKnife small radiosurgical fields

Abstract

Background: To determine the basic physical and dosimetric proper es of a new synthe c single-crystal diamond detector and its applica on for rela ve small field dosimetry. Materials and Methods: The pre-irradia on dose required to stabilize detector response, dose rate dependence, photon and electron energy dependence, temperature dependence and angular dependence of MicroDiamond detector response were evaluated. Output factors on Leksell Gamma Knife Perfexion and on CyberKnife were measured to assess detector feasibility in small radia on field dosimetry. For all measurements, the detector was connected to Unidos electrometer set to 0 voltage. Results: Rela ve output factors measured on Leksell Gamma Knife Perfexion for 4 mm and 8 mm collimators were in agreement with Monte Carlo reference values from the manufacturer, with devia ons of 0.3% and 2.1%, respec vely. For CyberKnife and fixed circular collimators, the difference in output factor values did not exceed 2% from vendor-supplied values, even for the smallest radia on field with a diameter of 5 mm. Conclusion: Our results indicate that the MicroDiamond detector is a promising tool for rela ve small field dosimetry. For output factor measurements on Leksell Gamma Knife Perfexion and CyberKnife, the detector can be used with minimal response correc ons applied (correc on factors not larger than 2%).