Relation between Teeth-dose and Effective Dose for External Photon Exposure

INTRODUCTION Electron spin resonance (ESR) dosimetry using dental enamel is expected to be applicable to individual dose assessments, in the case where no dose information can be obtained from dosimeters, such as radiation accident. This method is based on the assumption of the linear relation between intensity of ESR signal induced by CO3 radicals and the absorbed dose in dental enamel. The ESR signal has been related to the dose accumulated in teeth for external photon irradiation. Since the hydroxypatite crystal in the dental can easily trap free electrons in the defects in the crystal lattice and the signal in exposed dental enamel remains stable for a long time, ESR dosimetry using dental enamel has been applied to retrospective dose assessments in atomicbomb survivors, residents affected by the Chernobyl accident and accumulated individual doses of workers in Russian nuclear facility “Mayak”. The ultimate quantity is organ or tissue dose and effective dose, risk-weighted average of organ doses over a whole body for an estimation of individual dose. In this context, the retrospective dose assessment by ESR measurement requires a quantitative relationship between the effective dose and the dose in teeth. In this work, Monte Carlo calculations and experiments with a realistic head phantom were carried out to correlate quantitatively dose in teeth with effective dose for external photon exposure.