To determine the eye lens dose (3 mm dose equivalent [Hp(3)]) received by spine surgeons during myelography and evaluate the effectiveness of radiation-protective glasses and x-ray tube system positioning in reducing radiation exposure. This study included spine surgeons who performed myelography using over- or under-table x-ray tube systems. Hp(3) was measured for each examination using a radio-photoluminescence glass dosimeter (GD-352M) mounted on radiation-protective glass. This study identified significantly high Hp(3) levels, especially in the right eye lens in spinal surgeons. The median Hp(3) values in the right eye were 524 (391-719) and 58 (42-83)μSv/examination for over- and under-table x-ray tube systems, respectively. Further, Hp(3)AK, which was obtained by dividing the cumulative air kerma from Hp(3), was 8.09 (6.69-10.21) and 5.11 (4.06-6.31)μSv mGy-1for the over- and under-table x-ray tube systems, respectively. Implementing radiation-protective glasses resulted in dose reduction rates of 54% (50%-57%) and 54% (51%-60%) for the over- and under-table x-ray tube systems, respectively. The use of radiation protection glasses significantly reduced the radiation dose in the eye lens during myelography, with the most effective measures being the combination of using radiation protection glasses and an under-table x-ray tube system.

OBJECTIVE: Early 2018, the new eye lens dose limit of 20 mSv per year for occupational exposure to ionising radiation was implemented in the European Union. Dutch guidelines state that monitoring is compulsory above an expected eye lens dose of 15 mSv/year. In this study we propose a method to investigate whether the eye lens dose of interventionalists would exceed 15 mSv/year and to determine if the eye lens dose can be derived from the regular personal dosimeter measurements.
METHODS: The eye lens dose, Hp(3), of interventional radiologists (n = 2), cardiologists (n = 2) and vascular surgeons (n = 3) in the Máxima Medical Centre, The Netherlands, was measured during six months, using thermoluminescence dosimeters on the forehead. Simultaneously, the surface dose, Hp(0,07), and whole body dose, Hp(10), were measured using regular dosimeters outside the lead skirt at chest level. The dosimeters were simultaneously refreshed every four weeks. The eye lens dose was compared to both the body-worn dosimeter values. Measurements were performed in the angiography suite, Cath lab and hybrid OR.
RESULTS: A clear relation was observed between the two dosimeters: Hp(3) ≈ 0,25 Hp(0,07). The extrapolated year dose for the eye lens did not exceed 15 mSv for any of the interventionalists (average 3 to 10 studies/month).
CONCLUSIONS: The eye lens dose can be monitored indirectly through the regular dosimeter at chest level. Additionally, based on the measurements we conclude that all monitored interventionalists remain below the dose limit and compulsory monitoring limit for the eye lens dose.

18F has been the most widely used radionuclide in positron emission tomography (PET) facilities over the last few decades. However, increased interest in novel PET tracers, theranostics and immuno-PET has led to significant growth in clinically used positron-emitting radionuclides. The decay schemes of each of these radioisotopes are markedly different from18F, with different endpoint energies for the emitted positrons and, in some cases, additional high energy gamma radiation. This has implications for the occupational exposure of personnel involved in the manipulation and dispensing of PET radiopharmaceuticals. The EGSnrc Monte Carlo simulation software was used to estimate the doses to extremities in contact with unshielded and shielded syringes containing64Cu,18F,11C,13N,15O,68Ga and89Zr, respectively. Dose rates at various distances from the syringe were also modelled, with dose rates reported in terms of eye (Hp(3)), skin equivalent (Hp(0.07)) and deep (Hp(10)) doses. The composition and geometry of the simulated syringe shields were based on a selection of commercially available PET shields. Experimental dose rate measurements were performed for validation purposes where possible. Contact skin dose rates for all isotopes, except for64Cu, were found to be higher than18F for the unshielded syringe. The addition of a shield resulted in approximately equal contact skin dose rates for nearly all isotopes, for each shield type, with the exception of89Zr which was notably higher. Dose rate constants (µGy/MBq.hr) for a range of PET isotopes and shields are presented and their significance discussed.

OBJECTIVE: The issue of exposure of eye lenses of employees exposed to ionizing radiation is an interesting topic not only from the point of view of deterministic effects related to the occurrence of cataracts, but also dosimetric aspects, in particular the calibration of detectors in units enabling the assessment of eye lens exposure or personal dose equivalent Hp(3). The paper presents the idea of calibrating thermoluminescent detectors designed for the Hp(3) values measurement of gamma radiation, which the source is the process of annihilation of positrons emitted by the deoxyglucose marker - 18F radionuclide.
METHODS: The method was based on the value of air kerma Ka to Hp(3) conversion coefficients (Hp(3,0°)/Ka) developed as part of the ORAMED project. High-sensitivity thermoluminescent detectors (MCP-N) produced in Poland were used in the measurements. During the exposure of the detectors, a 137Cs gamma radiation source (irradiator 137Cs/60Co) and a 20cm diameter cylinder filled with water were used.
CONCLUSIONS: The value of conversion coefficient Hp(3,0°)/Ka for energy 511 keV is 1.31Sv/Gy and the calibration factor is (3.46±0.03)·10-4 mSv/N (N - number of counts). Verification of the value of the obtained coefficient carried out using a cylinder with a diameter of 20cm showed a difference of less than 2% in relation to the value obtained by the method described in this paper.

OBJECTIVE: The International Commission on Radiological Protection recommended that interventional radiologies (IRs) have high radiation doses and that staff may also be exposed to high doses. In the present study, we measured the radiation exposure dose [3 mm dose equivalent, Hp (3) ] in the eye using an appropriate dosimeter placed next to the physician\' s eye during neurovascular intervention procedure (Neuro-IR) and interventional cardiac electrophysiology procedure (EP-IR).
METHODS: Physicians wore a direct eye dosemeter just lateral to the left eye and an additional direct eye dosemeter outside the radiation protective glasses close to their left eye. Additionally, a neck badge [0.07 mm dose equivalent, Hp (0.07) ] was worn outside the protective apron to the left of the neck, to compare the direct eye dosimeter estimated doses. The occupational eye lens dose was evaluated over a period of 6-month.
RESULTS: The maximum Hp (3) of the Neuro-IR physician was estimated 5.1 mSv without the radiation protective glasses and 1.6 mSv with the radiation protective glasses. On the other hand, the maximum Hp (3) of the EP-IR physician was estimated 29 mSv without the radiation protective glasses and 15 mSv with the radiation protective glasses.
CONCLUSIONS: Physicians eye lens dose [Hp (3) ] tended to be overestimated by the neck badge measurements [Hp (0.07)]. A correct evaluation of the lens dose [Hp (3) ] using the direct eye dosimeter is recommended. Although we found a positive correlation between Hp (0.07) and Hp (3), the value of R2 in the regression equation is low, we recommended that the eye lens dose estimated carefully from Hp (0.07).

OBJECTIVE: Individual dosimetry allows to quantify doses from ionizing radiation of exposed workers. Scientific and epidemiological evidences highlight the need for adequate measures for a greater protection of the eye and a reduction in annual doses. ICRP Publication 103, illustrating the operational dose quantity Hp(d) for the individual monitoring, proposes a depth d = 3 mm for eye lens monitoring, indicating that even the Hp(0.07) can be used. In this study, it was investigated if there are differences in the evaluation of the equivalent dose to eye lens (Hlens) using Hp(3) or Hp(0.07).
METHODS: A slab phantom calibration was performed by an Accredited Calibration Laboratory in terms of Hp(3) and Hp(0.07) using ext-rad TLD-100 (LiF:Mg,Ti) dosimeters. Hp(0.07) and Hp(3) were measured for 26 exposed workers to assess Hlens. The measuring took place monthly in 2017 to obtain both semestral and annual doses.
RESULTS: Hlens(0.07) was always smaller than Hlens(3). However, the differences were not statistically significant (Mann-Whitney test, p > 0.05) for both semestral and annual doses. The percentage differences were 7 ± 3%, 6 ± 3% and 7 ± 2% for I semester, II semester and whole year, respectively. The mean underestimation index <10%, intra-class correlation coefficient >0.99, coefficient of variation <3% and the excellent correlation (R2 ≈ 0.999) for both semestral and annual doses highlighted that Hp(0.07) can be used to evaluate Hlens instead of Hp(3).
CONCLUSIONS: No statistical evidence was found that the use of Hp(0.07) underestimates the equivalent dose to eye lens obtained through Hp(3).