Active dosimeters used in interventional radiology and their response in pulsed radiation beams. Impact in clinical practice

AIM: To investigate and quantify the influence of the pulsed nature of clinical irradiation beams on the response of a specific type of active personal dosimeter (APD), and to evaluate its impact on individual occupational dose measurements of interventional radiologists and cardiologists. METHODS: APD responses were compared against passive dosimeters in a controlled experimental setting. Deviations outside the devices' specifications were addressed using a two-step correction model. A correction method based on the non-paralyzable dead-time model was developed using the instantaneous dose rate per pulse extracted from the Radiation Dose Structured Report (RDSR) at the irradiation-event level. After determining the appropriate correction factor, the method was applied to one year of clinical data comprising approximately 250,000 irradiation events. RESULTS: Among 24 occupational APDs evaluated, 14 required corrections, with the largest addition to the cumulative dose being 3.1 ± 0.1%. Five dosimeters mounted on C-arms showed that 6.61% of recorded events required correction, with a maximum correction of 5.52 ± 0.02%. Overall, the impact of pulsed radiation on recorded occupational doses was limited. CONCLUSIONS: Although the overall influence of pulsed radiation beams on APD-recorded doses was modest, verification of potential count-loss effects remains important to ensure the accuracy of cumulative dose measurements. With appropriate correction measures, APDs can be reliably used to support optimization of radiological protection for interventional specialists.