Type testing of an extremity finger stall dosemeter based on Harshaw TLD EXTRAD™ technology

The current status and issues regarding positron dosimetry in nuclear medicine are summarized. The suitability of the UKHSA extremity and eye beta-gamma personal thermoluminescence dosemeters are then considered. Monte Carlo modelling is performed to determine their responses and derive sets of calibration factors, along with Hp(0.07) and Hp(3) conversion coefficients, for carbon 11, nitrogen 13, oxygen 15, fluorine 18 and gallium 68 sources, which are commonly used in PET-CT; data for these isotopes is assumed extrapolatable to other positron sources. It is found that the dosemeters are adequate for assessing exposures to PET radionuclides, even if their routine calibrations to caesium 137 were maintained. An idealized set of measurements representing gallium 68 exposure scenarios is then described, including reproducible mock-ups of individuals manipulating vials and syringes. Finally, a short case-study is presented that explores occupational doses during routine clinical use of gallium 68. The extremity dosemeter results demonstrated significant variations dependent upon the exposure conditions, with some seen to be comparatively large; whole-body and eye dose rates per activity were found to be lower. The importance of routine dose monitoring of workers is emphasized, with the need for a longer-termed follow-up study demonstrated.

Section: Ukhsa Personal Dosemetersmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Personal dosimetry for positron emitters, and occupational exposures from clinical use of gallium-68

Eakins¹,

Hager²,

O'Connor³

et al. 2022

“…The Berkeley Approved Dosimetry Service (Berkeley ADS) provides a monitoring service for 22 nuclear sites in the UK using active personal dosemeters (APDs), i.e. the Thermo Fisher Scientific EPD, for measuring H p (10) and H p (0.07) [3,4] supplemented by TLDs for extremity and eye (eye TLD) [5,6] as appropriate for the workplace field. The EPD H p (0.07)/H p (10) ratio is dependent on the work being carried out at each site.…”

Section: Introductionmentioning

confidence: 99%

“…137Cs ±10%; Hp(0.07) 90 Sr/ 90 Y ±20%In use at 22 nuclear licensed sites in UK as the approved dosemeter for H P(10) and H p (0.07)Worn on trunk, usually at chest height[3,4,8] p (0.07)Previously used for eye monitoring until replaced in 2014 with the H P (3) TLD shown below[5,6] Harshaw EXTRAD in holder with 1.5 mm PTFE for eye monitoring Usually worn taped inside a safety visor or respirator (above eye level) where there is a significant beta component-for H P (3)[6] …”

mentioning

confidence: 99%

Eye lens dose monitoring in the UK nuclear industry using active personal dosemeters

McWhan¹,

Dobrzynska²

2018

The reduction of the dose limit for eye lens from 150 to 20 mSv yr must be implemented by EU member states by February 2018. Consequently, there is a requirement for all employers engaged with work with ionising radiation to have appropriate monitoring arrangements in place by this date to demonstrate that they can meet this new limit for all workers. Eye lens dose is conventionally monitored by specific dosemeters worn near the eye. However, it is usually impractical for these dosemeters to be worn at all times in the workplace which can lead to problems accounting for any periods of work when an eye lens dosemeter has not been worn. The Berkeley Approved Dosimetry Service provides a monitoring service for 22 nuclear sites in the UK using active personal dosemeters (APDs) for measuring H (10) and H(0.07). TLDs for extremity and eye are also issued as appropriate for the working conditions. An analysis of the data from 2007 to 2016 concludes that the values for H (0.07) as monitored indirectly by APDs worn on the trunk are comparable to the values assessed by specific H(3) eye TLDs. This paper sets out evidence that compliance with the 20 mSv dose limit for the eye lens can be demonstrated using routine issue APDs although specific eye TLDs may still be required to meet international guidance for non-uniform workplace fields. This evidence supports the recent statement from International Radiation Protection Association that 'for the nuclear industry and other non-medical sectors the use of a whole body dosimeter is considered likely to be sufficient for the majority of workers'.

“…The monitoring of workers constitutes a very important task for any radiological protection programme (Wrzesien et al 2006). Thermoluminescent (TL) dosimeters are usually considered to be suitable for workers occupationally exposed to ionising radiations (Vanhavere et al 2006, Gilvin et al 2006, Rimpler and Barth 2007, Brasik et al 2007.…”

Section: Introductionmentioning

confidence: 99%

Application of a wrist dosimeter prototype for radiation monitoring (¹⁵³Sm) during a therapeutic procedure simulation

Cecatti¹,

Guimarães²,

Caldas³

2009

Gamma and beta radiation emitting radiopharmaceuticals are handled in nuclear medicine services, and in many cases there is only individual monitoring of gamma radiation. In this paper, the results obtained using a wrist dosimeter prototype (CaSO(4):Dy+Teflon pellets) show that the doses for workers occupationally exposed to beta radiation from (153)Sm are not negligible. It is important that this dose is evaluated, and it has to be taken into consideration in the individual monitoring system.