69 research outputs found
What Is Worth Knowing in Interventional Practices about Medical Staff Radiation Exposure Monitoring: A Review of Recent Outcomes of EURADOS Working Group 12
No full textEURADOS (European Radiation Dosimetry Group) Working Group 12 (WG12) SG1 activities are aimed at occupational radiation protection and individual monitoring in X-ray and nuclear medicine practices. In recent years, many studies have been carried out in these fields, especially for interventional radiology and cardiology workplaces (IC/IR). The complexity of the exposure conditions of the medical staff during interventional practices makes the radiation protection and monitoring of the exposed workers a challenging task. The scope of the present work is to review some of the main results obtained within WG12 activities about scattered field characterization and personal dosimetry that could be very useful in increasing the quality of radiation protection of the personnel, safety, and awareness of radiation risk. Two papers on Monte Carlo modelling of inter-ventional theater and three papers on active personal dosimeters (APDs) for personnel monitoring were considered in the review. More specifically, Monte Carlo simulation was used as the main tool to characterize the levels of exposure of the medical staff, allowing to determine how beam energy and direction can have an impact on the doses received by the operators. Indeed, the simulations provided information about the exposure of the operator’s head, and the study concluded with the determination of an eye-lens protection factor when protection goggles and a ceiling shielding are used. Moreover, the review included the results of studies on active personal dosimeters, their use in IC/IR workplaces, and how they respond to calibration fields, with X-ray standard and pulsed beams. It was shown that APDs are insensitive to backscatter radiation, but some of them could not respond correctly to the very intense pulsed fields (as those next to the patient in interventional practices). The measurements during interventional procedures showed the potential capability of the employment of APDs in hospitals
Comparative organ dose levels for dentomaxillofacial examinations performed with computed tomography, cone beam CT and panoramic radiographs
No full textThe purpose of this study was to evaluate the radiation dose delivered to radiosensitive organs (thyroid, parotid glands and eye lens) during dentomaxillofacial imaging with multislice computed tomography (CT), cone beam CT (CBCT) and panoramic radiographs (orthopantomography, OPT). The dose was estimated individually for each modality and each clinical protocol by measuring the absorbed dose at the surface of a head phantom with thermoluminescence dosimeters. The measured radiation dose was between 0.01–1.22 mGy for the thyroid gland (systematically outside the primary beam), 1.34–29.11 mGy for the parotid glands (systematically exposed to the primary beam) and 0.02–26.22 mGy for the eye lens (in the primary beam depending on imaging protocol). For all organs, CT was found to be the most irradiating modality followed by CBCT and OPT. However, CBCT with a “limited dental” protocol and OPT deliver similar doses to the parotid glands
Comparative organ dose levels for dentomaxillofacial examinations performed with computed tomography, cone beam CT and panoramic radiographs
No full textDoses et qualité d’images : retours d’expériences dans le cadre d’appels d’offres des équipements à rayonnements ionisants
No full textEye lens monitoring programme for medical staff involved in fluoroscopy guided interventional procedures in Switzerland
No full textEpidemiological studies indicate that radiation damages to the eye lens occurs at lower dose values than previously considered (Worgul et al., 2007; Chodick et al., 2008; Ciraj-Bjelac et al., 2010; Rehani et al., 2011; Vano et al., 2010) [1], [2], [3], [4], [5]. The International Commission on Radiological Protection lowered the equivalent dose limit value for the eye lens to 20 mSv/year (ICRP, n.d.) [6]. This new limit has been incorporated into the revised Swiss legislation [7]. Prior this change, it was agreed that if the effective dose limit was respected it would implicitly imply the respect of the limit to the eye lens, for penetrating radiation. The concept had to be reviewed in the light of necessary application of the new eye lens dose limit. The new Swiss legislation proposes to use the value of Hp(0.07) measured over the protective apron to estimate the eye lens dose.
This study aims to investigate the validity of this approach for medical staff during fluoroscopy guided procedures. The results show that the ratio between thorax and eye lens doses varies greatly from one medical speciality to another, but also between surgeons within the same speciality. Moreover, for a given physician, the ratio varied over the periods of surveillance. Those variations confirmed the crucial influence of external parameters related to experience, practice and workload. The surveillance method is appropriate for most of the procedures performed in the department included in this study. Nevertheless, for the particular configuration in urology, the respect of the effective dose limit measured by the routine dosimetry does not allow direct compliance with the dose limit to the eye lens, unless appropriate protective eye wear gear are worn
An overview on extremity dosimetry in medical applications
No full textInternational audienceSome activities of EURADOS Working Group 9 (WG9) are presently funded by the European Commission (CONRAD project). The objective of WG9 is to promote and co-ordinate research activities for the assessment of occupational exposures to staff at workplaces in interventional radiology (IR) and nuclear medicine. For some of these applications, the skin of the fingers is the limiting organ for individual monitoring of external radiation. Therefore, sub-group 1 of WG9 deals with the use of extremity dosemeters in medical radiation fields. The wide variety of radiation field characteristics present in a medical environment together with the difficulties in measuring a local dose that is representative for the maximum skin dose, usually with one single detector, makes it difficult to perform accurate extremity dosimetry. Sub-group 1 worked out a thorough literature review on extremity dosimetry issues in diagnostic and therapeutic nuclear medicine and positron emission tomography, interventional radiology and interventional cardiology and brachytherapy. Some studies showed that the annual dose limits could be exceeded if the required protection measures are not taken, especially in nuclear medicine. The continuous progress in new applications and techniques requires an important effort in radiation protection and training. © The Author 2008. Published by Oxford University Press. All rights reserved
Conceptual Design of the LHC Beam Dumping Protection Elements TCDS and TCDQ
No full textThe Beam Dumping System for the Large Hadron Collider, presently under construction at CERN, consists, per ring, of a set of horizontally deflecting extraction kicker magnets, vertically deflecting steel septa, dilution kickers and finally, a couple of hundred metres further downstream, an absorber block. A fixed diluter (TCDS) will protect the septa in the event of a beam dump that is not synchronised with the particle free gap or a spontaneous firing of the extraction kickers which will cause the beam to sweep over the septum. Another, mobile, diluter block (TCDQ) will protect the superconducting quadrupole immediate downstream of the extraction as well as the arc at injection energy and the triplet aperture at top energy from bunches with small impact parameters. This paper describes the conceptual design of the protection elements
Patient exposure dose in interventional cardiology per clinical and technical complexity levels. Part 1: results of the VERIDIC project
No full textBackground: Patients can be exposed to high skin doses during complex interventional cardiology (IC) procedures. Purpose: To identify which clinical and technical parameters affect patient exposure and peak skin dose (PSD) and to establish dose reference levels (DRL) per clinical complexity level in IC procedures. Material and Methods: Validation and Estimation of Radiation skin Dose in Interventional Cardiology (VERIDIC) project analyzed prospectively collected patient data from eight European countries and 12 hospitals where percutaneous coronary intervention (PCI), chronic total occlusion PCI (CTO), and transcatheter aortic valve implantation (TAVI) procedures were performed. A total of 62 clinical complexity parameters and 31 technical parameters were collected, univariate regressions were performed to identify those parameters affecting patient exposure and define DRL accordingly. Results: Patient exposure as well as clinical and technical parameters were collected for a total of 534 PCI, 219 CTO, and 209 TAVI. For PCI procedures, body mass index (BMI), number of stents ≥2, and total stent length >28 mm were the most prominent clinical parameters, which increased the PSD value. For CTO, these were total stent length >57 mm, BMI, and previous anterograde or retrograde technique that failed in the same session. For TAVI, these were male sex, BMI, and number of diseased vessels. DRL values for Kerma-area product (PKA), air kerma at patient entrance reference point (Ka,r), fluoroscopy time (FT), and PSD were stratified, respectively, for 14 clinical parameters in PCI, 10 in CTO, and four in TAVI. Conclusion: Prior knowledge of the key factors influencing the PSD will help optimize patient radiation protection in IC
International workshop on optimization of radiation protection of medical staff, ORAMED 2011
No full textInternational audience[No abstract available
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