Extremity dosimetry problems during the handling of radionuclides syringes in nuclear medicine: A Monte Carlo radiation transport simplified approach

The ORAMED (Optimization of RAdiation protection for MEDical staff) Working Tasks (WP4) is addressed at evaluating extremity doses (and dose distributions across the hands) of medical staff working in nuclear medicine departments, to study the influence of protective devices such as syringe and vial shields, to improve such devices when possible and to propose “levels of reference doses” for each standard nuclear medicine procedure.In particular task 4 is concerned with the study of the extremity dosimetry for the hand of operators devoted to the preparation and administration stages of the usage, for example, of 99mTc, 18F and 90Y (Zevalin) radionuclides.The aim of this report consists in the study of photon-electron equilibrium conditions at 0.07 mm in the skin to justify a simplified “kerma approximation” approach in the planned complex Monte Carlo voxel hand modeling. Furthermore a detailed investigation on primary electron and secondary bremsstrahlung photon transport from 90Y to speed up the calculations was performed.The results obtained in the simplified investigated conditions could be of help for the production calculations, introducing, if necessary, suited correction factors applicable to the complex condition results.