Intercomparison and constancy check of brachytherapy well-type chambers as a means to improve the quality of measurements in Serbia.

Source strength measurements are of critical importance for brachytherapy and are often performed in hospitals using well-type chambers. Quality assurance and quality control procedures should be implemented, but that may prove difficult in some hospitals due to the lack of equipment or metrological support. A study was conducted to investigate the status of the measurement equipment in Serbian hospitals and to organize an intercomparison campaign using a hospital 192Ir source. All the hospitals were able to measure the source strength with the required accuracy, but the quality assurance can be improved. Two hospitals performed stability checks, which were evaluated. Uncertainty budget was created during the exercise and is presented in this paper. The described methodology can be used to quickly assess the performance of brachytherapy centers, and can be easily adapted to calibration procedure.

Characterization of Thermoluminescent Dosimetry Systems According to the IEC 62387:2020 Standard.

ABSTRACT: A need for detailed testing of individual monitoring systems used in accredited service at the Vinca Institute of Nuclear Sciences was recognized following changes in individual, workplace, and environmental monitoring passive dosimetry systems acceptability criteria stated in IEC 62387:2020 and changes related to reference fields used in radiation protection defined in ISO 4037:2019. Reliability and accuracy of dosimetry data acquired by passive dosimetry systems used for individual monitoring is assured by carrying out type tests. In this manner, the effects of different radiation influence quantities are examined. Passive dosimetry systems comprised of an LiF:Mg,Ti (TLD-100) detector card placed in two different holder models (8814 and 8850) and the Harshaw TLD Model 6600 Plus Automated Reader were tested. Type tests were done in an extended range of photon energies from 40 keV up to 1.25 MeV, angle of incidence values of ±45° and ± 60° for both vertical and horizontal dosimeter orientation, and in the dose range from 0.05 mSv to 1 Sv. Both dosimetry system configurations perform in line with IEC 62387:2020 within mandatory range for tested influence quantities. Dosimeters that use the 8850 holder type showed less pronounced energy and angular dependence of the response in the low-energy range.

Vendor-independent skin dose mapping application for interventional radiology and cardiology.

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 following interventional radiology and cardiology procedures using the realistic 3D patient models. Skin dose is calculated using data from Digital Imaging and Communications in Medicine (DICOM) Radiation Dose Structured Reports (RDSRs). SkinCare validation was performed by using the data from the Siemens Artis Zee Biplane fluoroscopy system and conducting "Acceptance and quality control protocols for skin dose calculating software solutions in interventional cardiology" developed and tested in the frame of the VERIDIC project. XR-RV3 Gafchromic films were used as dosimeters to compare peak skin doses (PSDs) and dose maps obtained through measurements and calculations. DICOM RDSRs from four fluoroscopy systems of different vendors (Canon, GE, Philips, and Siemens) were used for the development of the SkinCare and for the comparison of skin dose maps generated using SkinCare to skin dose maps generated by different commercial software tools (Dose Tracking System (DTS) from Canon, RadimetricsTM from Bayer and RDM from MEDSQUARE). The same RDSRs generated during a cardiology clinical procedure (percutaneous coronary intervention-PCI) were used for comparison. RESULTS: Validation performed using VERIDIC's protocols for skin dose calculation software showed that PSD calculated by SkinCare is within 17% and 16% accuracy compared to measurements using XR-RV3 Gafchromic films for fundamental irradiation setups and simplified clinical procedures, respectively. Good visual agreement between dose maps generated by SkinCare and DTS, RadimetricsTM and RDM was obtained. CONCLUSIONS: SkinCare is proved to be very convenient solution that can be used for monitoring delivered dose following interventional procedures.

Radon measurements using open-faced charcoal canisters - Measurement uncertainty and method optimization.

Open-faced charcoal canisters have been used for radon measurements for over 40 years. This method is sensitive to temperature, changing radon concentrations, humidity and other parameters, but a comprehensive study dealing with the influence quantities and measurement uncertainty was not available in literature. In this paper, all the identified influence quantities are discussed in detail, uncertainty budget is developed, good practice and bad practice examples are introduced and new recommendations are proposed to optimize the method and reduce uncertainty.

Response of TL and OSL passive personal dosimetry systems in poly-energetic and multi-directional photon radiation fields.

The aim of this paper is to examine the energy and angular responses of thermoluminescent dosimeters containing either MTS-N (LiF:Mg,Ti) or MCP-N (LiF:Mg,Cu,P) detector materials, and of the InLight optically stimulated luminescent dosimeters containing Al2O3:C detectors. Ten radiation qualities, with mean energies ranging from 24 keV to 1.25 MeV, and five angles of incidence, between 0° and 80°, were used for this purpose. The dosimeter response measure of quality were the IEC 62387 requirements. The experimental results show that the MTS-N-based and the InLight dosimeters performed in line with the standard's criteria. On the other hand, the MCP-N-based dosimeters exhibited a pronounced under-response around the energy of 120 keV, which resulted in deviations from the standard's conditions for both the energy and angular responses.

Performance Testing Of Selected Types of Electronic Personal Dosimeters in X- and Gamma Radiation Fields.

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. This testing is done in order to simulate the behavior of these dosimeters in realistic multidirectional polyenergetic ionizing radiation fields. Tests of accuracy, linearity, energy response, and angular response have been performed on 10 EPDs from multiple manufacturers. Various radiation qualities have been used in the energy range from 33 keV to 1.33 MeV and for angles of incidence 0° to 80°. This research proves that many of the EPDs tested performed according to the manufacturer's specifications and the requirements of the international standards regarding personal dosimetry.