Reductions in finger doses for radiopharmaceutical dispensing afforded by a syringe shield and an automatic dose dispenser

A gamma extremity monitoring system (GEMS) has been used to measure finger doses during radionuclide dispensing procedures. GEMS uses a small semi-con ductor probe that can be attached to a finger from which a continuous read- out can be obtained that is related to dose rate. The pattern of dose accum ulation can be analysed to allow doses received from individual operations within a procedure to be evaluated. GEMS has been used to compare the radia tion dose reduction afforded by a syringe shield and an automatic dose disp enser. Dispensing procedures were simulated using 10% of the activity norma lly administered in order to avoid problems with detector saturation. Resul ts show that the syringe shield and the automatic dose dispenser reduced fi nger doses by more than a factor of 10 for the procedures tested. The disad vantages of the automatic dispenser tested were a failure to transfer activ ity in 10% of cases and a longer time taken for the dispensing process. GEM S has the potential to facilitate greater optimization of finger doses thro ugh analysis of finger dose patterns. ((C) 1999 Lippincott Williams & Wilki ns).