Experimental Validation of Algorithms Used to Estimate Effective Dose During Interventional Radiology Procedures

Abstract

In IR procedures, in order to evaluate the effective dose, the importance of the double dosemeter has been recognised, one worn above and one under the apron. Over the last few decades several algorithms have been developed to combine the readings of the dosemeters, however currently there is no international consensus on which is the best one. In this work, eight irradiations, corresponding to typical interventional radiology procedures, were carried out in order to experimentally verify the accuracy of the algorithms. The patient was substituted by solid water-equivalent (RW3) layers, while effective dose to personnel was calculated by TLDs inside the Alderson Rando phantom. The results show that most of the algorithms, with a few exceptions, are too conservative, however there are many factors which can affect their accuracy, so it is impossible to achieve a high level of precision in the evaluation of the effective dose.

Practical guidelines for personal monitoring and estimation of effective dose and dose to the lens of the eye in interventional procedures

“…Following the conclusions of Negri et al [17], in this study we assume as the best estimate of the effective dose, E ref , the mean value (see equation ( 3)) of the following three algorithms of double dosimetry: (10) under + 0.05H p (10) over [18],…”

“…From our analysis we cannot identify which double-dosimetry algorithm provides the best assessment of the effective dose, but previous works showed that there is no ideal algorithm. Depending on the exposure situation [4,17] and also on the personal dosemeter calibration and performance [22] one algorithm can be considered better than another. In summary, the use of two dosemeters does not significantly improve the assessment of the effective dose in fluoroscopically guided interventional procedures, in general, except in situations where it is possible to approach or exceed the effective dose limit (20 mSv per year).…”