RAdiation Protection For MEDical Staff Research Articles

Ratios of Eye Lens and Hand Equivalent Doses with Whole-Body Effective Doses for Operators Performing Interventional Radiological Procedures.

Estimating radiation doses for operators performing interventional radiological procedures is crucial in the occupational radiation protection of medical staff. In this study, Monte Carlo simulations coupled with an anthropomorphic phantom were used to model various exposure scenarios during the procedures. Conversion coefficients of the dose-area product of x rays for the eye lens equivalent dose, hand equivalent dose, and whole-body effective dose of the operator were calculated. Accordingly, the relationships between these dose quantities in typical interventional configurations were established, considering various source locations, tube voltages, and use of protective equipment or not. The results are presented in a systematic way for easy comparison and use. Tables and figures of the data can be helpful to provide estimates of eye lens and hand equivalent doses when records of specific dosimeters are absent, such as in the retrospective assessment of operators' eye lens and hand equivalent doses in past practices.

Radiation Reduction and Protection for Radiosensitive Organs (Lens, Thyroid, and Genital Organs) of Patients Receiving Percutaneous Coronary Intervention-Real-World Measurement of Radiation Dose in a Single Center.

Backgrounds: Reducing radiation exposure is the basic principle for performing percutaneous coronary intervention (PCI). Many studies have confirmed the effect of radiation protection for medical staff, but studies about the effectiveness of protection for patients and real measurement of radiation dose in patients’ specific organs are lacking. Aim: To measure the radiation doses absorbed by patients’ radiosensitive organs during PCI and the effectiveness of radiation protection. Methods: A total of 120 patients were included and allocated into three groups as the ratio of 1:1:2. A total of 30 patients received PCI at 15 frames rate per second (fps), 30 patients at 7.5 fps, and 60 patients wore radiation protective hat and glasses during PCI at 7.5 fps. The radiation doses were measured at right eyebrow (lens), neck (thyroid), back (skin), and inguinal area (genital organs) by using thermoluminescent dosimeters (TLDs). Results: Dose-area product (DAP) reduced by 58.8% (from 534,454 ± 344,660 to 220,352 ± 164,101 mGy·cm2, p < 0.001) after reducing the frame rate, without affecting successful rate of PCI. Radiation doses measured on skin, lens, genital organs, and thyroid decreased by 73.3%, 40.0%, 40.0%, and 35.3%, respectively (from 192.58 ± 349.45 to 51.10 ± 59.21; 5.29 ± 4.27 to 3.16 ± 2.73; 0.25 ± 0.15 to 0.15 ± 0.15; and 17.42 ± 12.11 to 11.27 ± 8.52 μSv, p < 0.05). By providing radiation protective equipment, radiation doses at lens and thyroid decreased further by 71.8% and 65.9% (from 3.16 ± 2.73 to 0.89 ± 0.79; 11.27 ± 8.52 to 3.84 ± 3.49 μSv, p < 0.05). Conclusions: By lowering the frame rate and providing protective equipment, radiation exposure in radiosensitive organs can be effectively reduced in patients.

RADIATION EXPOSURE DURING SPINE SURGERY USING C-ARM FLUOROSCOPY.

ABSTRACTObjective:To evaluate the radiation dose received by staff in spine surgeries, including those who are not considered occupationally exposed workers.Methods:All spinal surgeries performed in the same department during a period of 12 months were evaluated with regard to the exposure of surgeons, scrub nurses, and auxiliary personnel working in the operating room to radiation from C-arm fluoroscopy. Radiation was measured by 15 film badge dosimeters placed on the professionals’ lapels, gloves, and room standardized sites. The films were analyzed in the dosimetry laboratory by collections per period.Results:During the 12 months, 81 spinal surgeries were performed by the same team, with surgical times ranging from 1 to 6 hours. The total radiation dose ranged from 0.16 mSv to 2.29 mSv depending on the dosimetry site. The most exposed site was the wrist of the main surgeon.Conclusion:The results showed that in the spinal surgeries in our setting, the radiation doses are low and within legal limits. Nevertheless, constant training of professionals is essential for radiation protection of medical staff and patients. Level of evidence I/b, exploratory cohort study.

Investigation of radiation protection of medical staff performing medical diagnostic examinations by using PET/CT technique

Positron emission tomography (PET) is now one of the most important methods in the diagnosis of cancer diseases. Due to the rapid growth of PET/CT centres in Poland in less than a decade, radiation protection and, consequently, the assessment of worker exposure to ionising radiation, emitted mainly by the isotope 18F, have become essential issues. The main aim of the study was to analyse the doses received by workers employed in the Medical Diagnostic Centre. The analysis comprises a physicist, three nurses, three physicians, three technicians, as well as two administrative staff employees. High-sensitivity thermoluminescent detectors (TLDs) were used to measure the doses for medical staff. The personnel was classified into categories, among them employees having direct contact with the ‘source of radiation’—18FDG. The TLDs were placed on the fingertips of both hands and they were also attached at the level of eye lenses, thyroid and gonads depending on the assigned category. The highest dose of radiation was observed during the administration of the 18FDG to the patients. In the case of the physicist, the highest dose was recorded during preparation of the radiopharmaceutical—18FDG. The body parts most exposed to ionizing radiation are the fingertips of the thumb, index and middle finger.

水晶体の放射線防護に関する専門研究会中間報告書 (Ⅲ)

Many studies have been internationally reported as part of projects regarding the radiation exposure for the lens of the eye of medical staff members under various conditions, methods of dosimetry and development of dosimeters for the lens of the eye. Recently conducted studies include the Retrospective Evaluation of Lens Injuries and Dose (RELID) of the International Atomic Energy Agency, Occupational Cataracts and Lens Opacities in interventional Cardiology (O’CLOC) study in France, Optimization of Radiation Protection of Medical Staff (ORAMED) project in European countries, and a 20-year prospective cohort study among US radiologic technologists. Given the newly implemented dose limit for the lens of the eye by the International Commission on Radiological Protection (ICRP), we summarized these studies as the necessary information for reconsideration of the Japanese dose limit for the lens of the eye. In addition, this article also covers the exposures for the lens of the eye of clean-up workers in the Chernobyl accident as shown in ICRP Publication 118 and the results of a hearing survey with specialists of the Academy of Medical Science of Ukraine.

Fluence to Hp(3) conversion coefficients for neutrons from thermal to 15 MeV

The recent statement on tissue reactions issued by the International Commission on Radiological Protection in April 2011 recommends a very significant reduction in the equivalent dose annual limit for the eye lens from 150 to 20 mSv y(-1); this has stimulated a lot of interest in eye lens dosimetry in the radiation protection community. Until now no conversion coefficients were available for the operational quantity Hp(3) for neutrons. The scope of the present work was to extend previous evaluations of H*(10) and Hp(10) performed at the PTB in 1995 to provide also Hp(3) data for neutrons. The present work is also intended to complete the studies carried out on photons during the last 4 y within the European Union-funded ORAMED (optimisation of radiation protection for medical staff) project.

Air kerma to HP(3) conversion coefficients for photons from 10 keV to 10 MeV, calculated in a cylindrical phantom

In the framework of the ORAMED project (Optimization of RAdiation protection for MEDical staff), funded by the European Union Seventh Framework Programme, different studies were aimed at improving the quality of radiation protection in interventional radiology and nuclear medicine. The main results of the project were presented during a final workshop held in Barcelona in January 2011, the proceedings of which are available in the open literature. One of the ORAMED tasks was focused on the problem of eye-lens photon exposure of the medical staff, a topic that gained more importance especially after the ICRP decision to lower the limiting equivalent dose to 20 mSv per year. The present technical note has the scope, besides briefly summarising the physical reasons of the proposal and the practical implications, to provide, in tabular form, a set of air kerma to Hp(3) conversion coefficients based on the adoption of a theoretical cylindrical model that is well suited for reproduction of the mass and the shape of a human head.

RADIATION EXPOSURE OF MEDICAL STAFF: APPLICATION OF HAND PHANTOMS IN EXPERIMENTS AND SIMULATIONS

To evaluate extremity doses and optimize radiation protection of medical staff, we investigated examples in nuclear medicine and CT fluoroscopy. In addition to measurements with medical staff on-site and with real hand phantoms, selected scenarios were simulated with hand phantoms. Besides simulations of static hand poses also modeling based on consecutive frames from video recordings during handling scenarios was realized. These procedures are useful tools to reveal highest exposures which in turn could promote initiating optimized radiation protection measures.

International Workshop on Optimization of Radiation Protection of Medical Staff, ORAMED 2011

International Workshop on Optimization of Radiation Protection of Medical Staff, ORAMED 2011

What are the implications of the proposed revision of the eye dose limit for interventional operators?

What are the implications of the proposed revision of the eye dose limit for interventional operators?

Measurements of eye lens doses in interventional radiology and cardiology: Final results of the ORAMED project

Abstract Within the ORAMED project (Optimization of Radiation Protection of Medical Staff) a coordinated measurement program for occupationally exposed medical staff was performed in different hospitals in Europe ( www.oramed-fp7.eu ). The main objective was to obtain a set of standardized data on extremity and eye lens doses for staff involved in interventional radiology and cardiology and to optimize radiation protection. Special attention was given to the measurement of the doses to the eye lenses. In this paper an overview will be given of the measured eye lens doses and the main influence factors for these doses. The measured eye lens doses are extrapolated to annual doses. The extrapolations showed that monitoring of the eye lens should be performed on routine basis.

Extremity doses of medical staff involved in interventional radiology and cardiology: Correlations and annual doses (hands and legs)

Abstract An intensive measurement campaign was launched in different hospitals in Europe within work package 1 of the ORAMED project (Optimization of RAdiation protection for MEDical staff). Its main objective was to obtain a set of standardized data on extremity and eye lens doses for staff in interventional radiology (IR) and cardiology (IC) and to optimize staff protection. The monitored procedures were divided in three main categories: cardiac, general angiography and endoscopic retrograde cholangio-pancreatography(ERCP) procedures. Using a common measurement protocol, information such as the protective equipment used (lead table curtain, transparent lead glass ceiling screen, patient shielding, whole body shielding or special cabin etc.) as well as Kerma Area Product (KAP) values and access of the catheter were recorded. This study was performed with a final database of more than 1300 procedures performed in 34 European hospitals. Its objectives were firstly to determine if the measured extremity doses could be correlated to the KAP values; secondly to check if the doses to the eyes could be linked to the doses to the hands (finger or wrist positions) and finally if the doses to the fingers could be estimated based on the doses to the wrists. General correlations were very difficult to find and their strength was mostly influenced by three main parameters: the X-ray tube configuration, the room collective radioprotective equipment and the access of the catheter. The KAP value can provide a simple mean to estimate the extremity doses of the operator given that it is assessed correctly for the operator when he is actually using the X-ray tube. Moreover, this study showed that the doses to the left finger are strongly correlated to the doses to the left wrist when no ceiling shield is used. It is also possible to estimate the doses to the eyes given the doses to the left finger or left wrist but the X-ray tube configuration and the access have to be considered. The annual finger doses of three workers were estimated and were found to exceed the 3/10thof the annual limit. Therefore, for the hands routine monitoring is necessary especially for interventional cardiology procedures, except for ERCP procedures. If the table shield is properly used, leg doses can be reduced significantly and no routine monitoring is necessary.

Proposals for the type tests criteria and calibration conditions of passive eye lens dosemeters to be used in interventional cardiology and radiology workplaces

Abstract The paper is aimed at making a proposal for the type test and calibration of eye lens passive dosemeters especially used in the interventional cardiology/radiology (IC/IR). Starting from the only existing standard dealing with eye lens dosimetry using TLDs ( ISO 12794 ), parameters such as, detection threshold, energy and angle dependence of response criteria have been reviewed and it has been tried to harmonise them as much as possible with the IEC 62387 requirements, taking into account the particular use at IC/IR workplaces. Conversion coefficients from air kerma to dose equivalent at 3 mm depth for RQR and ISO radiation qualities, employed for type test and calibration purposes, have been calculated in a new phantom introduced within the ORAMED (Optimization of RAdiation protection for MEDical staff) project. This phantom is more representative of the head so that the estimation of H lens by H p (3) is more accurate.

ICRP and radiation protection of medical staff

Committee 3 (Protection in Medicine) and Committee 4 (Application of Recommendations) of the International Commission on Radiological Protection (ICRP) deal with the protection of medical staff. In the last 10 years, the Committee on Protection in Medicine has been involved in the preparation of 12 publications, some of which include specific recommendations on occupational RP. This paper summarizes the most relevant aspects of these recommendations on RP for medical staff. The most recent publication on Radiation Dose to Patients from Radiopharmaceuticals contains an annex on hand exposure in radio-pharmacies. Radiation detriment from exposure of both radiological staff and other individuals is considered as part of the justification of medical exposures and of the optimization process. ICRP advises on the uncertainty concerning the risk of cataracts and puts particular emphasis on optimization in situations of exposure of the eyes. Some recommendations on staff protection are included in the documents on computed tomography, digital radiology, pregnancy, discharge of patients after therapy and interventional radiology. The contents related to staff RP in the coming publications of the Committee (pediatric, cardiology, and fluoroscopy) are also summarized.

Radiation protection of medical staff in the latest draft of the revised Euratom Basic Safety Standards directive

Abstract The European Union has a long and successful history of legislating in the area of radiation protection of the public, workers and individuals submitted to medical exposure, the first Euratom “Basic Safety Standards” (BSS) adopted in 1959 and subsequently updated and supplemented with other Directives. The recent revision of this legislation aims to update it in the light of the latest knowledge and experience and to simplify it by consolidating the current legal acts into one Directive. The draft of the revised Euratom BSS Directive has been approved by the group of scientific experts under Euratom Treaty Article 31 and is currently undergoing the European Commission’s procedures. This draft contains several new or amended provisions relating to protection of medical staff, among them: (i) a streamlining of the annual dose limit provisions, (ii) enhancing the use of dose constraints in optimization of protection, and (iii) ensuring better recording and transfer of occupational dose data including in cases of trans-border movement of workers. The Community action to radiation protection of workers is not restricted to passing relevant legislation but also includes ‘soft action’ as issuing guidance, supporting research and stakeholders’ involvement, etc. In August 2010 the Commission issued a Communication to the Council and the European Parliament dealing with the issues in the medical uses of ionizing radiation, including those relating to radiation protection of medical staff.

Eye lens dosimetry: task 2 within the ORAMED project

The ORAMED (Optimization of RAdiation protection for MEDical staff) project is funded by EU-EURATOM within the 7° Framework Programme. Task 2 of the project is devoted to study the dose to the eye lens. The study was subdivided into various topics, starting from a critical revision of the operational quantity H(p)(3), with the corresponding proposal of a cylindrical phantom simulating as best as possible the head in which the eyes are located, the production of a complete set of air kerma to dose equivalent conversion coefficients for photons from 10 keV to 10 MeV, and finally, the optimisation of the design of a personal dosemeter well suited to respond in terms of H(p)(3). The paper presents some preliminary results.

Extremity dosimetry problems during the handling of radionuclides syringes in nuclear medicine: A Monte Carlo radiation transport simplified approach

Abstract The ORAMED (Optimization of RAdiation protection for MEDical staff) Working Tasks (WP4) is addressed at evaluating extremity doses (and dose distributions across the hands) of medical staff working in nuclear medicine departments, to study the influence of protective devices such as syringe and vial shields, to improve such devices when possible and to propose “levels of reference doses” for each standard nuclear medicine procedure. In particular task 4 is concerned with the study of the extremity dosimetry for the hand of operators devoted to the preparation and administration stages of the usage, for example, of 99mTc, 18F and 90Y (Zevalin) radionuclides. The aim of this report consists in the study of photon-electron equilibrium conditions at 0.07 mm in the skin to justify a simplified “kerma approximation” approach in the planned complex Monte Carlo voxel hand modeling. Furthermore a detailed investigation on primary electron and secondary bremsstrahlung photon transport from 90Y to speed up the calculations was performed. The results obtained in the simplified investigated conditions could be of help for the production calculations, introducing, if necessary, suited correction factors applicable to the complex condition results.

A new proposal on the operational quantity Hp(3): Monte Carlo and experimental results

Abstract The European Union is funding the ORAMED Contract (Optimization of RAdiation protection for MEDical staff) project that aims at developing methodologies for better assessing and reducing exposures to medical staff for procedures resulting in potentially large doses or complex radiation fields, such as interventional radiology, nuclear medicine and new developments. One of the ORAMED Working Tasks is addressed to the discussion and implementation in the radiation protection practice of the eye lens equivalent dose. The aim of this task group is to develop a personal dosemeter characterized in term of H p (3). Until now H p (3) conversion coefficients were not reported in the official recommendations and the available data were calculated for a 30 × 30 × 15 cm 3 slab phantom that is far away to represent the head. A reduced slab phantom, for both calculating the quantities and type testing personal dosemeter in terms of the operational quantity, was previously proposed by ENEA Bologna team. The study demonstrated that a reduced slab phantom is better representative of a real situation, but the angular dependence of H p (3,α) due to the edges of the slab reduces its applicability. Therefore a better-suited phantom is proposed here. The dosimetric assessment in terms of this quantity is seldom performed in the various workplaces (e.g. hospitals) and therefore a question rises about its usefulness and practical implementation. The present work tries to introduce new elements in the discussion on the quantity H p (3) and to propose a more suitable theoretical cylindrical phantom (and a corresponding experimental one for the calibration procedures) to better approximate the head in which the eyes are placed.

Monte Carlo determination of the conversion coefficients Hp(3)/Ka in a right cylinder phantom with 'PENELOPE' code. Comparison with 'MCNP' simulations

This work has been performed within the frame of the European Union ORAMED project (Optimisation of RAdiation protection for MEDical staff). The main goal of the project is to improve standards of protection for medical staff for procedures resulting in potentially high exposures and to develop methodologies for better assessing and for reducing, exposures to medical staff. The Work Package WP2 is involved in the development of practical eye-lens dosimetry in interventional radiology. This study is complementary of the part of the ENEA report concerning the calculations with the MCNP-4C code of the conversion factors related to the operational quantity H(p)(3). In this study, a set of energy- and angular-dependent conversion coefficients (H(p)(3)/K(a)), in the newly proposed square cylindrical phantom made of ICRU tissue, have been calculated with the Monte-Carlo code PENELOPE and MCNP5. The H(p)(3) values have been determined in terms of absorbed dose, according to the definition of this quantity, and also with the kerma approximation as formerly reported in ICRU reports. At a low-photon energy (up to 1 MeV), the two results obtained with the two methods are consistent. Nevertheless, large differences are showed at a higher energy. This is mainly due to the lack of electronic equilibrium, especially for small angle incidences. The values of the conversion coefficients obtained with the MCNP-4C code published by ENEA quite agree with the kerma approximation calculations obtained with PENELOPE. We also performed the same calculations with the code MCNP5 with two types of tallies: F6 for kerma approximation and *F8 for estimating the absorbed dose that is, as known, due to secondary electrons. PENELOPE and MCNP5 results agree for the kerma approximation and for the absorbed dose calculation of H(p)(3) and prove that, for photon energies larger than 1 MeV, the transport of the secondary electrons has to be taken into account.

ENEA extremity dosemeter based on LiF(Mg,Cu,P) to evaluate Hp(3, )

Recent epidemiological studies suggest a rather low-dose threshold (<0.5 Gy) for the induction of a cataract of the eye lens. Some other studies even assume that there is no threshold at all. Therefore, protection measures have to be optimised and current dose limits for the eye lens may be reduced in the future. ICRP Publication 103 on H(p)(d), in §(136), reads that '… a depth d = 3 mm has been proposed for the rare case of monitoring the dose to the lens of the eye. In practice, however, H(p)(3) has rarely been monitored and H(p)(0.07) can be used for the same monitoring purpose… '. As recommended on the EU 'Technical recommendations for monitoring individuals occupationally exposed to external radiation', a test on the ENEA TL extremity dosemeter is herein reported. The results within the actual EU founded Optimization of RAdiation protection for MEDical staff (ORAMED) Project, whose WP2 is aimed at the quantity H(p)(3) and eye lens dosimetry in practice, are taken into account. The paper summarises the main aspects of the study carried out at ENEA-Radiation Protection Institute (Bologna, Italy) to provide practical solutions (in the use and the design) to evaluate the response of the ENEA TL extremity dosemeter in terms of H(p)(3).