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

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.

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.

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.

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.