Olivera Ciraj-Bjelac

Vinča Institute of Nuclear Sciences | VIN · Radiation and Environmental Protection

Passive solid state dosimeters, such as thermoluminescence dosimeters, provide integrated measurement of the total dose and are widely used in environmental monitoring programs. The objective of this paper is to provide a comprehensive review on the use of thermoluminescent dosimetry methods for monitoring radiation dose in the environment. The art...

The objective of this work was to assess absorbed doses in organs and tissues of a rabbit, following computed tomography (CT) examinations, using a dedicated 3D voxel model. Absorbed doses in relevant organs were calculated using the MCNP5 Monte Carlo software. Calculations were perfomed for two standard CT protocols, using tube voltages of 110 kVp...

The purpose of this work is to assess accuracy and compare the performance of radionuclide calibrators (RNCs) used in nuclear medicine departments in Serbia. Testing of the RNCs included verification of measurement accuracy, as well as analysis of routinely used quality control protocols, by using the certified radioactivity standards (⁵⁷Co, ¹³⁷Cs)...

Purpose The purpose of this work is to provide a comprehensive analysis of uncertainties associated with the use of software solutions utilizing DICOM RDSRs for skin dose assessment in the interventional fluoroscopic environment. Methods and Results Three different scenarios have been defined for determining the overall uncertainty, each with a sp...

Occupational radiation doses from interventional procedures have the potential to be relatively high. The requirement to optimise these doses encourages the use of electronic or active personal dosimeters (APDs) which are now increasingly used in hospitals. They are typically used in tandem with a routine passive dosimetry monitoring programme, wit...

The use of patient contact-shielding has become a topic of intensive scientific debate. While it has been common practice during the last decades, some studies have questioned the efficiency of using such shielding while others have highlighted the inconsistencies in its application. The objective of this work is to review current recommendations a...

Due to the need for harmonization of passive dosimetry and the requirements of the international standards in the area of environmental monitoring in radiation protection, multiple types of various passive dosimetry systems based on different ionizing radiation detection mechanisms were subjected to extensive performance testing. In the scope of th...

One of the objectives of the EMPIR project 16ENV04 “Preparedness” is the harmonization of methodologies for the measurement of doses with passive dosimetry systems for environmental radiation monitoring in the aftermath of a nuclear or radiological event. In such cases, measurements are often performed at low radiation dose rates, close to the dete...

Purpose Online and offline software products can estimate the maximum skin dose (MSD) delivered to the patient during interventional cardiology procedures. The capabilities and accuracy of several skin dose mapping (SDM) software products were assessed on X-ray systems from the main manufacturers following a common protocol. Methods Skin dose was...

13th EURADOS Winter School Eye Lens Dosimetry, EURADOS Report 2021-01

Interventional procedures in radiology and cardiology are associated with high dose to the patient. Accurate dosimetry is essential and calibration of the equipment is a means to provide the necessary accuracy of dose assessment. The objective of this work is to investigate the performance of dosimeters used in interventional procedures in differen...

Cone beam computed tomography has been available since the late 1990s for use in dentistry. European legislation requires optimisation of protection and the use of diagnostic reference levels (DRLs) as well as regular quality control of the imaging devices, which is well outlined in the existing international recommendations. Nevertheless, the leve...

Purpose: The purpose of this paper is to present and validate an originally developed application SkinCare used for skin dose mapping in interventional procedures, which are associated with relatively high radiation doses to the patient's skin and possible skin reactions. Methods: SkinCare is an application tool for generating skin dose maps fol...

Purpose In interventional cardiology, patients may be exposed to high doses to the skin resulting in skin burns following single or multiple procedures. Reviewing and analysing available software (online or offline) may help medical physicists assessing the maximum skin dose to the patient together with the dose distribution during (or after) these...

In the absence of information on radiation doses in mammography in the Gulf countries, this study was designed to assess patient dose in terms of entrance surface air kerma and average glandular dose (AGD) in three mammography units in Qatar that covers 21% of all mammography systems in the country. The study of 150 patients involving 600 projectio...

Medical personnel performing interventional procedures in cardiology and radiology is considered to be a professional group exposed to high doses of ionizing radiation. Reduction of the eye lens dose limit made its assessment in the interventional procedures one of the most challenging topics. The objective of this work is to assess eye lens doses...

Medical staff in interventional procedures are among the professionals with the highest occupational doses. Active personal dosemeters (APDs) can help in optimizing the exposure during interventional procedures. However, there can be problems when using APDs during interventional procedures, due to the specific energy and angular distribution of th...

Objectives Cone beam computed tomography (CBCT) in dentistry and maxillofacial surgery is a widely used imaging method for the assessment of various maxillofacial and dental pathological conditions. The objective of this study was to summarize the results of a multinational retrospective-prospective study that focused on patient exposure in this mo...

Growing concern for radiological and nuclear safety and growing use of radiation protection instruments by both professionals and lay persons increase the need for low cost and reliable instrumentation. The aim of this work was to develop a radiation protection instrument that will be both affordable to the widest radiation protection community, in...

Medical staff performing interventional procedures in cardiology and radiology is considered to be a professional group exposed to high doses of ionizing radiation. With new epidemiological evidences and recently reduced eye lens dose limit, dose assessment to the lens of the eye, in the interventional cardiology, has become one of the most challen...

Purpose Low dose radiation effect on the eye lens has been an area of interest in numerous epidemiological studies. The European epidemiological study EURALOC was conducted between December 2014 and May 2017 with the objective to investigate a possible dose-response relationship by targeting a sufficiently large study population with reasonably hig...

Interventional cardiac procedures may be associated with high patient doses and therefore require special attention to protect the patients from radiation injuries such as skin erythema, cardiovascular tissue reactions or radiation-induced cancer. In this study, patient exposure data is collected from 13 countries (37 clinics and nearly 50 interven...

This paper investigates over five decades of work practices in interventional cardiology with special emphasis on radiation protection. The analysis is based on the data from more than 400 cardiologists from different European countries recruited for EURALOC study collected in the period from 2014 to 2016. Information on the types of procedures per...

Considering that occupational exposure in medicine is a matter of growing concern, active personal dosimeters (APD) are also increasingly used in different fields of application of ionising radiation in medicine. An extensive survey to collect relevant information for the use of APDs in medical imaging applications of ionising radiation was organiz...

This study describes the retrospective lens dose calculation methods developed and applied within the European epidemiological study on radiation-induced lens opacities among interventional cardiologists. While one approach focuses on self-reported data regarding working practice in combination with available procedure-specific eye lens dose values...

Purpose: The feasibility of setting-up generic, hospital-independent dose alert levels to initiate vigilance on possible skin injuries in interventional procedures was studied for three high-dose procedures (chemoembolization (TACE) of the liver, neuro-embolization (NE) and percutaneous coronary intervention (PCI)) in 9 European countries. Method...

In recent years, computed tomography (CT) has become very common in veterinary medicine. It is well known that testicles are organs with high radiosensitivity and their function can be impaired even after exposure to low radiation doses. In this work, we calculated the absorbed radiation doses after CT was performed with different voltage/current l...

The objective of this study was to assess the radiation dose in computed tomography examinations of rabbits using different examination protocols and to correlate these values with the activity of antioxidant enzymes in their red blood cells following irradiation. The presented results revealed that a single, routine computed tomography scan exposu...

Electronic personal dosimeters (EPDs) are increasingly being used alongside conventional thermoluminescent dosimeters to measure the dose of legal record in terms of personal dose equivalent. Therefore, it is of great importance to execute performance tests of these dosimeters in photon fields of various energies and at various angles of incidence....

Introduction The eye lens radiation-induced risk has been assessed for various population groups. In the framework of the European epidemiological study, EURALOC, an attempt is made to determine a possible dose-response relationship by targeting interventional cardiologists, a group of high exposure values. Purpose In the study, eye lens doses are...

Occupational exposure from interventional x-ray procedures is one of the areas in which increased eye lens exposure may occur. Accurate dosimetry is an important element to investigate the correlation of observed radiation effects with radiation dose, to verify the compliance with regulatory dose limits, and to optimize radiation protection practic...

The purpose of this study was to assess the patient exposure and staff eye dose levels during implantation procedures for all types of pacemaker therapy devices performed under fluoroscopic guidance and to investigate potential correlation between patients and staff dose levels. The mean eye dose during pacemaker/defibrillator implementation was 12...

Fluoroscopy procedures may lead to increased radiation exposure of radiologists and other staff members. The objective of the study is to assess whole body radiation doses and doses to the eye in fluoroscopy procedures, based on measurements that allow for estimates of occupational doses when personal dosimeters have not been used. Four geometrical...

The purpose of this study is to investigate the radiation dose and technical image quality in mammography in Serbia after two years of implementation of the breast screening programme. A total of 186 mammography units, including Full-Field Digital Mammography (FFDM), Computed Radiography (CR) and Screen-Film Mammography (SFM) units were used in the...

Manipulation of unsealed radiation sources in nuclear medicine (NM) departments involves non-uniform exposure to staff and high skin doses to the upper extremities from direct and scattered radiations. Conducted studies have shown that the annual dose limits could be exceeded and the continuous dose monitoring of NM worker's hands is needed. The ai...

The objective of this work is to assess the occupational dose in interventional cardiology in a large hospital in Belgrade, Serbia. A double-dosimetry method was applied for the estimation of whole-body dose, using thermoluminescent dosemeters, calibrated in terms of the personal dose equivalent Hp(10). Besides the double-dosimetry method, eye dose...

A comparison of calibration results and procedures in terms of air kerma length product, PKL, and air kerma, K, was conducted between eight dosimetry laboratories. A pencil-type ionization chamber (IC), generally used for computed tomography dose measurements, was calibrated according to three calibration methods, while its residual signal and othe...

Radiografski pregledi u stomatologiji predstavljaju najmasovniju grupu radioloških pregleda. Iako je doza po jednom pregledu relativno mala, dozimetrijska merenja predstavljaju značajni ulazni podatak sa stanovništa procene doze za populaciju. Za potrebe ovog rada, vršena su ispitivanja incidentna kerma (incident air kerma) i proizvoda doze i površ...

A thorough literature review about the current situation on the implementation of eye lens monitoring has been performed in order to provide recommendations regarding dosemeter types, calibration procedures and practical aspects of eye lens monitoring for interventional radiology personnel. Most relevant data and recommendations from about 100 pape...

Intercomparisons are important activities performed to ensure that the services provided by calibration laboratories to end-users follow internationally accepted standards. Ionizing radi-ation dosimetry intercomparisons are usually of two types-postal thermoluminescent do-simeter intercomparisons and ionization chamber calibration intercomparisons....

Purpose: Point detectors are frequently used to measure patient’s maximum skin dose (MSD) in fluoroscopically-guided interventional procedures (IP). However, their performance and ability to detect the actual MSD are rarely evaluated. The present study investigates the sampling uncertainty associated with the use of grids of point detectors to meas...

To investigate the optimal use of XR-RV3 GafChromic(®) films to assess patient skin dose in interventional radiology while addressing the means to reduce uncertainties in dose assessment. XR-Type R GafChromic films have been shown to represent the most efficient and suitable solution to determine patient skin dose in interventional procedures. As f...

Pulse height distribution (PHD) registered by a spectrometer is influenced by various physical phenomena such as photon interactions as well as disturbance produced by the electronic circuits inside the spectrometer. Therefore, spectrometry measurements of gamma and x-ray radiation inaccurately represent primary spectra. In order to overcome spectr...

Objective of this work is to evaluate radiation exposure from X-ray examinations in a large paediatric hospital in Serbia, including radiographic, fluoroscopic and computed tomography (CT) examinations in four age groups: 0-1, 1-5, 5-10 and 10-15 y. Incident air kerma was assessed for the following radiographies: chest (AP, PA, LAT), spine (AP, LAT...

In this paper, the results of pMOS dosemeters sensitivity to X-ray radiation and 28-d fading at room temperature are presented. Two types of dosemeters were used, which differ in gate oxide layer thickness. The sensitivity of pMOS dosemeters with gate oxide layer thickness of 1 µm was followed in the dose intervals of 1 to 10 cGy and 10 to 100 cGy,...

Intercomparisons are important activities performed to ensure that the services provided by calibration laboratories to end-users follow internationally accepted standards. Ionizing radiation dosimetry intercomparisons are usually of two types - postal thermoluminescent dosimeter intercomparisons and ionization chamber calibration intercomparisons....

The EURAMET #1177 project, identified as EURAMET RI(I) - S9 comparison, was the first EURAMET wide scale supplementary comparison in the field of diagnostic radiology for air kerma area product, PKA, and air kerma, K. It was conducted with the goal of testing the measurement and calibration capabilities for PKA and K, as well as of supporting the r...

To help operators acknowledge patient dose during interventional procedures, EURADOS WG-12 focused on measuring patient skin dose using XR-RV3 gafchromic films, thermoluminescent detector (TLD) pellets or 2D TL foils and on investigating possible correlation to the on-line dose indicators such as fluoroscopy time, Kerma–area product (KAP) and cumul...

The aim of this work was to investigate the different types of radiation detectors commonly used for radiation protection purposes as survey meters. The study was performed on survey meters that use different detectors as ionisation chamber, Geiger Mueller (GM) counter and scintillation detector. For each survey meter, energy dependence and angular...

This work presents initial data on radiation doses in adult computed tomography (CT) in Serbia. Data were collected in terms of CT dose index (CTDIvol) and dose length product (DLP) values for head, chest and abdomen examination. The range of CTDIvol values was found to be 53–98, 11–34 and 8.5–227 mGy whereas for DLP was 803–1066, 350–845 and 1066–...

The purpose of this work is to evaluate the radiation exposure to nuclear medicine (NM) staff in the two positron emission tomography-computed tomography centres in Serbia and to investigate the possibilities for dose reduction. Dose levels in terms of Hp(10) for whole body and Hp(0.07) for hands of NM staff were assessed using thermoluminescence a...

In this paper, the results of radiation sensitive field effect transistors (Al-gate p-channel metal-oxide-semiconductor field effect transistors) sensitivity to gamma and X-ray irradiation are presented. Radiation fields were created using 60Co source for three dose ranges (0-1 Gy, 0-5 Gy, and 0-50 Gy), as well as X-ray unit of 280 kVp spectrum for...

The objective of this paper is to measure the radiation dose and image quality in conventional screen-film mammography and full-field digital mammography in women referred to mammography examination. Participants underwent bilateral, two-view screen-film mammography or full-field digital mammography. The visibility of anatomical regions and overall...

Interventional radiology and cardiology are areas with high potential for risk to eye lens. Accurate assessment of eye dose is one of the most important aspects of correlating doses with observed lens opacities among workers in interventional suites and ascertaining compliance with regulatory limits. The purpose of this paper is to review current a...

The paper describes dose response and signal fading of Al-gate p-channel (metal oxide semiconductor field effect transistors) MOSFETs in the range of gamma radiation doses used in radiation therapy. MOSFETs with thicknesses of the gate oxide layer of 1μm and 400nm were used. The response was characterized by the threshold voltage shift and was stud...

Investigation of Al-gate p-channel MOSFETs sensitivity following irradiation using 200 and 280 kV X-ray beams as well as gamma-ray irradiation of 60Co in the dose range from 1 to 5 Gy was performed in this paper. The response followed on the basis of threshold voltage shift and was studied as a function of absorbed dose. It was shown that the most...

This paper presents results from study on patient exposure level in chest CT examinations. CT scanners used in this study were various Siemens and General Electric (GE) models. Data on patient doses were collected for adult and pediatric patients. Doses measured for adult patients were lower then those determined as Diagnostic Reference Levels (DRL...

Interventional cardiology procedures are associated with high patient and staff dose levels. The purpose of this paper is to assess dose levels in terms of Hp(3) for different categories of staff working in interventional cardiology suite and to perform parallel patient dose assessment to correlate eye lens dose levels with relevant patient dose in...

Nuclear and isotope techniques are widely used in numerous areas of human activity and for more than century have prominent application in different areas including medicine. This section contains an overview of methods based on the application of gamma rays in medicine. Medical diagnostic and therapeutic procedures utilizing gamma-emitting radiois...

The purpose of this paper is to evaluate the image quality and dose to patients in the radiography of sacroiliac joints and to perform a clinical comparative study of digital and conventional screen-film radiography. Routine radiography of sacroiliac joint was performed in 60 patients using digital and screen-film radiography. The visibility of fiv...

Workers involved in interventional cardiology procedures receive high eye lens dose if protection is not used. Currently, there is no suitable method for routine use for the measurement of eye dose. Since most angiography machines are equipped with suitable patient dosemeters, deriving factors linking staff eye doses to the patient doses can be hel...

Background: Recent studies have reported a significant increase in eye lens opacities among staff in the cardiac catheterization laboratory but indicated further studies are needed to confirm the findings. Objective: To evaluate the prevalence of opacities in eyes of cardiologists, radiographers and nurses working in interventional cardiology....

The purpose of this study was to investigate radiation doses in cerebral perfusion computed tomography (CT) examination. As a part of routine patient monitoring, data were collected on patients in terms of the skin dose and CT dose index (CTDIvol) and dose-length product (DLP) values. For the estimation of the dose to the lens a phantom study was p...

This paper presents an estimation of local diagnostic reference levels in computed tomography in a large teaching hospital. Local diagnostic reference levels, expressed in terms of volume weighted computed tomography dose index and dose-length product, were estimated for three most frequent adult computer tomography examinations: head, abdomen and...

Recognizing the lack of information on image quality and patient doses in most countries in Asia, the International Atomic Energy Agency (IAEA) initiated a project to assess the status of imaging technology, practice in conventional radiography, mammography, computed tomography (CT) and interventional procedures, and to implement optimisation actio...

This study was undertaken to explore the effects of the jaws and the MLC openings on the neutron dose equivalent (DE) at the maze door and neutron flux at the patient plane. The neutron dose equivalent was measured at the maze entrance door of a 15 MV therapy linear accelerator room. All measurements were performed using various field sizes up to 4...

Breast cancer is the most frequent malignant neoplasm affecting the female population. In order to reduce its morbidity and mortality rate, a mammography screening campaign has been established in both entities of Bosnia and Herzegovina. In this paper, a brief survey is given on the mammography screening practice in the Republic of Srpska. As an il...

It was the aim of the study presented here to estimate for the first time patient dose levels in conventional diagnostic radiology in Montenegro. Measurements of patient dose in terms of entrance surface air kerma (ESAK) and kerma-area product (KAP) were performed on at least 10 patients for each examination type, in each of five randomly selected...

When this paper was about to go to press, the International Commission on Radiological Protection released a statement recommending a change in the threshold dose for the eye lens and dose limits for eye for occupationally exposed persons. It is clear that the earlier published threshold for radiation cataract is no longer valid. Epidemiological st...