Assessment of eye and body dose for interventional radiologists, cardiologists, and other interventional staff

Abstract

A dose limit for the eye of 20 mSv, as proposed by the ICRP, could be exceeded by interventional clinicians. Data on eye dose levels for interventional radiologists and cardiologists provided by medical physicists from hospitals around the UK have been collated. The results indicate that most hospitals would require one or more interventional clinicians to be classified and several would have exceeded a 20 mSv limit. Dose data in the literature have been reviewed to derive factors that might be used to predict eye dose levels based on dose per procedure or kerma-area product workload. These could be used in prior risk assessments to establish monitoring practice. An alternative approach to personnel dose monitoring in radiology applications using a collar dosimeter worn outside the lead apron as the first dosimeter is proposed. The collar dosimeter would provide an assessment of eye dose in terms of Hp(3) and body dose in terms of Hp(10), which could be divided by ten to provide an assessment of effective dose. If Hp(3) exceeded 1 mSv per month, regular monitoring with a head dosimeter would be recommended, and if Hp(10) exceeded 2 mSv per month, then an under-apron dosimeter should also be worn.

Occupational radiation dose to eyes from interventional radiology procedures in light of the new eye lens dose limit from the International Commission on Radiological Protection

“…The average eye dose per unit KAP (left and right eyes) was calculated to be 1.2 mSv Gy 21 cm 22 . These results are broadly comparable with values quoted in the literature; 15,16 however, if left and right eye results are analysed separately, the dose per procedure and dose per unit KAP to the left eye will be higher. In addition, the accuracy of the KAP meter was considered, as this should be taken into account when normalizing data to KAP measurements (see the Discussion section below).…”

“…[1][2][3][4][5][6] While there is good awareness and understanding of radiation risks to staff from IR procedures, a lack of reliable values for eye doses has persisted. Recent publications have attempted to address this and have established that dose to the eyes can be significant, particularly if the X-ray tube is positioned over the patient table and if no ceiling-mounted lead screen or lead glasses are used; [7][8][9][10][11][12][13][14][15][16] however, more data on lens dose, particularly in terms of H p (3) (personal dose equivalent at 3 mm in soft tissue), is required. 15,16 Revised International Commission on Radiological Protection dose limit In April 2011, the International Commission on Radiological Protection (ICRP) published a statement on tissue reactions recommending an equivalent dose limit for the lens of the eye of 20 mSv per annum.…”

Occupational dose constraints for the lens of the eye for interventional radiologists and interventional cardiologists in the UK

“…5 There were a variety of radiation protection conditions with non-uniform uptake of CSSs and LG, which is currently typical. 4,5 Nonetheless, for IRs and ICs monitored on the head, in departments that always used CSSs, the respective maximum doses were approximately 24 and 20 mSv year 21 , neglecting LG. The publication does not state the age of the X-ray equipment used but is likely to include a range of specifications.…”

“…2 Publications suggest that interventionalist doses may exceed 20 mSv year 21 if protection measures, including both a ceiling-suspended eye shield (CSS) and lead glasses (LG), are not utilized. [2][3][4][5] Evidence of radiation effects in the lens suggests a dose threshold for cataract formation of 0.5 Gy for acute, fractionated and protracted exposure. However, for chronic exposure, much of the evidence refers to opacities rather than cataracts.…”

“…8 Guidance states that constraints are appropriate only where individual doses from a single source are a significant fraction of the limit. 9 As the EU directive 1 requires the undertaking to establish constraints, and eye doses for interventionalists are a significant fraction of a 20 mSv limit, [2][3][4][5]10 it is expected that UK implementation may require employers to develop and use constraints.…”