Extremity ring dosimetry intercomparison in reference and workplace fields

An intercomparison of ring dosemeters has been organised with the aim of assessing the technical capabilities of available extremity dosemeters and focusing on their performance at clinical workplaces with potentially high extremity doses. Twenty-four services from 16 countries participated in the intercomparison. The dosemeters were exposed to reference photon (137Cs) and beta (147Pm, 85Kr and 90Sr/90Y) fields together with fields representing realistic exposure situations in interventional radiology (direct and scattered radiation) and nuclear medicine (99 mTc and 18F). It has been found that most dosemeters provided satisfactory measurements of Hp(0.07) for photon radiation, both in reference and realistic fields. However, only four dosemeters fulfilled the established requirements for all radiation qualities. The main difficulties were found for the measurement of low-energy beta radiation. Finally, the results also showed a general under-response of detectors to 18F, which was attributed to the difficulties of the dosimetric systems to measure the positron contribution to the dos

Active personal dosemeters in interventional radiology: tests in laboratory conditions and in hospitals

The work package 3 of the ORAMED project, Collaborative Project (2008-11) supported by the European Commission within its seventh Framework Programme, is focused on the optimisation of the use of active personal dosemeters (APDs) in interventional radiology and cardiology (IR/IC). Indeed, a lack of appropriate APD devices is identified for these specific fields. Few devices can detect low-energy X rays (20-100 keV), and none of them are specifically designed for working in pulsed radiation fields. The work presented in this paper consists in studying the behaviour of some selected APDs deemed suitable for application in IR/IC. For this purpose, measurements under laboratory conditions, both with continuous and pulsed X-ray beams, and tests in real conditions on site in different European hospitals were performed. This study highlights the limitations of APDs for this application and the need of improving the APD technology so as to fulfil all needs in the IR/IC fiel

Test of active personal dosimeters for interventional radiology in realistic radiation fields

Abstract. In Interventional radiology, the medical staff stands close to the patient during his exposure to X-rays. Consequently, they can be exposed to relatively high doses due to radiation scattered by the patient and the medical equipment. Contrary to the passive dosemeters which assess the doses a posteriori, APDs are able to warn the medical staff when doses and/or dose rates exceed pre-defined radiation protection limits. At interventional radiology workplaces, APDs must be able to measure low-energy photons (10-120 keV) and pulsed radiations with relatively high instantaneous dose rates delivered by medical X-rays generators. Six ADP models, considered as suitable for application in interventional radiology on the basis of the results of a previous comparison jointly organised by EURADOS and IAEA, were selected to carry out a new comparison in 2007. This included radiation fields able to mimic the scattered and pulsed X-ray radiation fields met at workplace in hospitals. Irradiations took place at CEA-LIST LNHB (Saclay, France) and IRSN (Fontenay-aux-Roses, France). This paper describes the irradiation assemblies both for realistic and classic calibration facilities. The reference values of the personal dose equivalent, H p (10), were determined through measurements and simulations to calculate the response of the APDs. The results shed light on the ability of APDs to measure correctly the doses, when used in the specific low-energy spectra and dose rates of pulsed Xrays encountered in interventional radiology

Validity of an FFQ assessing the vitamin D intake of young Serbian women living in a region without food fortification: the method of triads model

Objective: The objective of the present study was to examine the external validity of an FFQ designed to estimate dietary vitamin D intake compared with a plasma biomarker and three repeated 24 h dietary recalls in women of reproductive age in Serbia, where there is no exposure to food fortified with vitamin D. The method of triads was applied. Design: In a cross-sectional study, 422 women completed the Women and Reproductive Health FFQ (WRH-FFQ) during the winter months. From a representative subgroup (n 44), three 24 h dietary recalls and anthropometric parameters were collected as well as a fasting blood sample for vitamin D biomarker analyses. Correlation coefficients were calculated between each of the dietary methods. Validity coefficients, as a correlation between the measured and estimated 'true' exposure, were calculated using the method of triads. Bland-Altman plots were also constructed. Setting: Three major universities in Serbia. Subjects: Healthy young women (n 422) aged 18-35 years. Results: The WRH-FFQ estimate of vitamin D intake for all participants was 4.0 (SD 3.3) mu g/d and 3.1 (SD 2.3) mu g/d for the subgroup. Bland-Altman plots for these intakes showed high agreement. Validity coefficients for the FFQ, 24 h recall and biomarker were. rho(QI) = 0.847 (95 % CI 0.564, 0.928), rho(RI) = 0.810 (95 % CI 0.537, 0.997) and rho(BI) = 0.499 (95 % CI 0.190, 0.840), while the correlation coefficients were 0.686, 0.422 and 0.404. Conclusions: The FFQ applied in the present study is a valid tool for assessing dietary vitamin D intake in women living in Serbia, a region without mandatory vitamin D food fortification

Extremity ring dosimetry intercomparison in reference and workplace fields

An intercomparison of ring dosemeters has been organised with the aim of assessing the technical capabilities of available extremity dosemeters and focusing on their performance at clinical workplaces with potentially high extremity doses. Twenty-four services from 16 countries participated in the intercomparison. The dosemeters were exposed to reference photon ((137)Cs) and beta ((147)Pm, (85)Kr and (90)Sr/(90)Y) fields together with fields representing realistic exposure situations in interventional radiology (direct and scattered radiation) and nuclear medicine ((99 m)Tc and (18)F). It has been found that most dosemeters provided satisfactory measurements of H(p)(0.07) for photon radiation, both in reference and realistic fields. However, only four dosemeters fulfilled the established requirements for all radiation qualities. The main difficulties were found for the measurement of low-energy beta radiation. Finally, the results also showed a general under-response of detectors to (18)F, which was attributed to the difficulties of the dosimetric systems to measure the positron contribution to the dose