Personal Dosimetry Using Monte-Carlo Simulations for Occupational Dose Monitoring in Interventional Radiology: The Results of a Proof of Concept in a Clinical Setting

Abstract

Exposure levels to staff in interventional radiology (IR) may be significant and appropriate assessment of radiation doses is needed. Issues regarding measurements using physical dosemeters in the clinical environment still exist. The objective of this work was to explore the prerequisites for assessing staff radiation dose, based on simulations only. Personal dose equivalent, Hp(10), was assessed using simulations based on Monte Carlo methods. The position of the operator was defined using a 3D motion tracking system. X-ray system exposure parameters were extracted from the x-ray equipment. The methodology was investigated and the simulations compared to measurements during IR procedures. The results indicate that the differences between simulated and measured staff radiation doses, in terms of the personal dose equivalent quantity Hp(10), are in the order of 30–70 %. The results are promising but some issues remain to be solved, e.g. an automated tracking of movable parts such as the ceiling-mounted protection shield.

Feasibility study of computational occupational dosimetry: evaluating a proof-of-concept in an endovascular and interventional cardiology setting

“…The results for some cases showed a significant difference across the three MC simulation packages. This has been observed similarly in the Swedish study [26] and possible reasons for this have been considered. One difference is a variation in the exact positioning of the field on the patient phantom, and the composition of the phantom that it used by the MC code.…”

“…Our study and a similar series of measurements in Sweden [26] have shown that it is feasible to simulate doses and the PODIUM concept has merit. Many technical challenges were solved and while there were some promising results, the study revealed difficulties and further challenges to be surmounted.…”

“…Three selected MC calculation codes are used to simulate occupational dose and compare it to dose measured with a physical dosimeter during interventional procedures on patients. This work is the second in a series of similar validation measurements performed at the Skane University Hospital in Malmo, Sweden, based on one experimental case and three clinical cases [26]. The three clinical cases in Malmo were performed in one interventional x-ray room with the camera in a fixed position in the ceiling and the results obtained were promising, with differences between simulated staff radiation doses, in terms of the personal dose equivalent quantity H p (10) of the order of 30%-70% with similar levels of differences between measurements and simulations.…”

“…There are also scenarios where the physical measuring device (APD) might underestimate exposure for example the operator may shield the dosemeter on their trunk with their arms during a procedure [26]. Another limitation of the PODIUM system is that it will only be compatible with modern systems capable of producing an RDSR.…”