DOSE MEASUREMENTS TO THE LENS IN NUCLEAR MEDICINE AND IN FLUOROSCOPY-GUIDED INTERVENTIONAL PROCEDURES: ANALYSIS OF THE RESULTS AND ASSESSMENT OF THE EFFECTIVENESS OF PROTECTIVE EYEWEAR ANTI-X

A cost-effective way to reduce the equivalent eye lens dose fromYttrium-90 radiopharmaceuticals

PURPOSE

We analyzed the effect of the use of Eye Protective Equipment (EPE) and the best position to use individual dosimeters to estimate the eye lens radiation dose to a medical staff that works with yttrium-90.

METHODS

Three Alderson-Head-Phantoms were exposed to 58MBq of ⁹⁰Y for 24h, in two different experiments: (1) at different dosimeter placements and (2) with and without the use of EPE. The measurements were carried on by thermoluminescent technique.

RESULTS

Doses received by dosimeters on both lenses were more closely represented by the ones placed between the eyes than those on the temples, which underestimated the doses by a factor of 3. Also, the transmission factors showed that the EPE was able to reduce the H_p(3) values from about 78% to 92%.

CONCLUSIONS

This study demonstrated that the use of EPE can optimize the ⁹⁰Y eye lens dose. An individual dosimeter should be worn between the eyes for an appropriate estimate of this equivalent dose.

Review of experimental estimates for the protection afforded by eyewear for interventional x-ray staff

This paper attempts to systematise all published experimental results for the dose reduction factor (DRF) offered by leaded eyewear on clinicians performing interventional procedures. We aim to present a comprehensive analysis of the issue and a comparison of the various equipment models at different exposure geometries. The main purpose of the paper is, however, to clarify the best choice for the DRF within the possible diverse contexts and approaches to eye lens dose assessment. Evidence has been obtained that the lowest estimates of DRF are associated with larger scatter incidence angles and that, except for the slightly better performance exhibited by wraparound eyeglasses, there is no real distinction between the DRFs for the different equipment categories. The dataset as a whole confirms that, when measurements for the concerned eyewear model and irradiation conditions are unattainable, assuming DRF = 2 represents an adequately conservative choice. Nonetheless, this value includes only 17% of all results from the literature, whereas their histogram follows a distribution skewed towards higher values, represented by a median equal to 5. Therefore, if more realistic dose reconstructions are necessary, such as for purposes of epidemiological investigations or compensation decisions, the adoption of this central tendency index appears to be more reasonable. The complexity of characterising the DRF behaviour as a function of the various exposure factors reinforces the consideration of a statistical approach to eye lens dose assessment as a viable alternative. In this perspective, assuming for DRF a lognormal distribution with parameters [Formula: see text] and [Formula: see text] which has been verified to satisfactorily approximate the literature data distribution, should be deemed to be an appropriate option.

A multicenter study of radiation doses to the eye lenses of medical staff performing non-vascular imaging and interventional radiology procedures in Japan

PURPOSE

This study aimed to measure the eye lens doses received by physicians and other medical staff participating in non-vascular imaging and interventional radiology procedures in Japan.

MATERIAL AND METHODS

From October 2014 to March 2017, 34 physicians and 29 other medical staff engaged in non-vascular imaging and interventional radiology procedures at 18 Japanese medical facilities. These professionals wore radioprotective lead glasses equipped with small, optically stimulated luminescence dosimeters and additional personal dosimeters at the neck during a 1-month monitoring period. The H_p(3) and the H_p(10) and H_p(0.07) were obtained from these devices, respectively. The monthly H_p(3), H_p(10), and H_p(0.07) for each physician and other medical staff member were then rescaled to a 12-month period to enable comparisons with the revised occupational equivalent dose limit for the eye lens.

RESULTS

Among physicians, the average annual H_p(3) values measured by the small luminescence dosimeters on radioprotective glasses were 25.5 ± 38.3 mSv/y (range: 0.4-166.8 mSv/y) and 9.3 ± 16.6 mSv/y (range: 0.3-82.4 mSv/y) on the left and right sides, respectively. The corresponding values for other medical staff were 3.7 ± 3.1 mSv/y (range: 0.4-10.4 mSv/y) and 3.2 ± 2.7 mSv/y (range: 0.5-11.5 mSv/y), respectively.

CONCLUSIONS

The eye lens doses incurred by physicians and other medical staff who engaged in non-vascular imaging and interventional radiology procedures in Japan were provided. Physicians should wear radioprotective glasses and use additional radioprotective devices to reduce the amount of eye lens doses they receive.