Staff eye lens dose in interventional radiology and cardiology in Finland

Purpose: The aim of this study was to investigate the eye lens and whole-body radiation doses to interventional radiology and cardiology staff in two Finnish hospitals. Methods: Simultaneous measurements of personal dose equivalent quantities H-p(3) and H-p(10) were conducted in clinical conditions during different radiological and cardiological interventional procedures. In order to study the feasibility to estimate eye lens dose with H-p(10) measured over the protective apron or thyroid shield, the ratio between measured H-p(3) and H-p(10) was investigated. Results and conclusions: Applying the obtained ratio on H-p(10) records from national dose register showed that only a small number of interventional radiologists and cardiologists in Finland may exceed eye lens equivalent dose levels of 20 mSv per year or 100 mSv in five consecutive years, but likely do not exceed 50 mSv in a single year. For the most Finnish interventionalists, the eye lens dose is well below 10 mSv per year. Nurses and radiographers assisting in interventions are, on average, less exposed than interventionalists, and will not exceed 20 mSv per year. Based on our results, H-p(10) measured over the protective apron or thyroid shield provides a conservative estimate of the eye lens dose for interventional radiologists and cardiologists, provided that appropriate protective glasses are used.Peer reviewe

Dental cone beam CT : An updated review

Cone beam computed tomography (CBCT) is a diverse 3D x-ray imaging technique that has gained significant popularity in dental radiology in the last two decades. CBCT overcomes the limitations of traditional twodimensional dental imaging and enables accurate depiction of multiplanar details of maxillofacial bony structures and surrounding soft tissues. In this review article, we provide an updated status on dental CBCT imaging and summarise the technical features of currently used CBCT scanner models, extending to recent developments in scanner technology, clinical aspects, and regulatory perspectives on dose optimisation, dosimetry, and diagnostic reference levels. We also consider the outlook of potential techniques along with issues that should be resolved in providing clinically more effective CBCT examinations that are optimised for the benefit of the patient.Peer reviewe

National Programme for Radiation Safety Research

Vuoden 2013 tutkimuslaitosuudistuksen myötä kansallista työnjakoa säteilyturvallisuuden tutkimuksessa on nyt tarkasteltu uudelleen. Suomeen perustetaan yliopistojen, korkeakoulujen ja STUKin välinen tutkimusyhteenliittymä. Yhteenliittymän työn pohjaksi on laadittu säteilyturvallisuuden tutkimusohjelma, jonka tavoitteena on kuvata tutkimustarpeet ja varmistaa korkeatasoinen kansallinen osaaminen ja tietopohja säteilyturvallisuudessa ja turvata kansallisten viranomaisten tiedon saanti. Säteilyturvallisuus kattaa sekä ionisoivan säteilyn että ionisoimattoman säteilyn. Keskeisiä tiedon tarpeita liittyy seuraaviin aiheisiin: - Säteily ja terveys: säteilyn terveyshaitat ja vaikutusmekanismit, lääketieteellinen säteilyn käyttö, potilasturvallisuus ja turvalliset hoito‐ ja diagnostiikkakäytännöt, työntekijöiden turvallisuus, riskitietoisuus ja –käyttäytyminen - Säteily ympäristössä: radonturvallinen rakentaminen, radioaktiivisten aineiden kulkeutuminen ympäristössä, elintarvikkeiden pitoisuudet ja niiden kautta tapahtuva altistuminen, vaikutukset eliökuntaan; kansalliset erityispiirteet - Säteilyuhkiin ja onnettomuuksiin varautuminen: onnettomuusvalmius ja turvajärjestelyt - Mittaukset ja teknologiat säteilyturvallisuudessa: metrologiaan ja dosimetriaan liittyvät innovaatiot, säteily‐ ja ydinturvallisuutta palvelevat sovellukset, ohjelmistot ja laitteet. Säteilyturvallisuus kattaa laajan kirjon tieteenaloja, aina säteily‐ ja ydinfysiikasta biolääketieteisiin, ympäristötieteisiin, tekniikkaan ja yhteiskunta‐ ja käyttäytymistieteisiin. Kotimaisista yliopistoista löytyy vahvaa tieteenalojen osaamista, ja tämä osaaminen saatetaan entistä paremmin mukaan yhteiskunnan tarpeista lähtevään säteilyturvallisuuden tutkimukseen. STUK suuntaa oman tutkimus‐ ja kehittämistoimintansa suoraan valvontaa ja valmiutta sekä turvajärjestelyjä tukeviin aiheisiin ja selvityksiin. Yliopistojen panosta tarvitaan erityi‐sesti laajoissa hankkeissa ja perustutkimusta ja soveltavaa tutkimusta edellyttävissä aiheissa, jotka liittyvät riskinarviointiin, teknologiseen kehittämiseen ja riskien hallintaan. STUK on ollut keskeisesti mukana luomassa eurooppalaisia tutkimusagendoja ja tutkimuksen yhteenliittymiä Euratom‐ohjelmassa. Tavoitteena on liittää kansallinen säteilyturvallisuuden ohjelma eurooppalaisiin säteilyturvallisuusalan ohjelmiin. Säteilyturvallisuustutkimuksen uudelleen järjestely edellyttää ohjelmaluonteista rahoitusta, jolla pystytään turvaamaan pitkäjänteinen osaamisen ylläpito ja kehittäminen monitietei‐sellä, koko yhteiskuntaa palvelevalla tutkimussaralla. STUK on aiemmin melko ketterästi pystynyt vastaamaan muiden viranomaisten ja hallinnonalojen säteilyturvallisuutta koskeviin kansallisiin kehittämistarpeisiin sekä antamaan asiantuntijatukea kansainvälisellä tasolla. Jatkossa rahoitusta yhteiskunnan kannalta merkittäviin tietotarpeisiin tulee osoittaa joko ministeriöiden oman tutkimusrahoituksen tai tutkimuslaitosuudistuksen yhteydessä perustettujen uusien rahoitusvälineiden, Valtioneuvoston kanslian selvitys‐ ja tutkimustoiminnan ja Suomen Akatemian strategisen tutkimuksen neuvoston kautta. Kansallisen sätei‐lyturvallisuustutkimuksen ohjelman linkittäminen H2020‐ohjelmaan ja kansainvälisistä tutkimusresursseista hyötyminen edellyttää kansallista vastinrahoitusta EU‐tutkimuksessa

Actual and Potential Radiation Exposures in Digital Radiology : Analysis of Cumulative Data, Implications to Worker Classification and Occupational Exposure Monitoring

Radiation worker categorization and exposure monitoring are principal functions of occupational radiation safety. The aim of this study was to use the actual occupational exposure data in a large university hospital to estimate the frequency and magnitude of potential exposures in radiology. The additional aim was to propose a revised categorization and exposure monitoring practice based on the potential exposures. The cumulative probability distribution was calculated from the normalized integral of the probability density function fitted to the exposure data. Conformity of the probabilistic model was checked against 16 years of national monitoring data. The estimated probabilities to exceed annual effective dose limits of 1 mSv, 6 mSv and 20 mSv were 1:1000, 1:20 000 and 1:200 000, respectively. Thus, it is very unlikely that the class A categorization limit of 6 mSv could be exceeded, even in interventional procedures, with modern equipment and appropriate working methods. Therefore, all workers in diagnostic and interventional radiology could be systematically categorized into class B. Furthermore, current personal monitoring practice could be replaced by use of active personal dosemeters that offer more effective and flexible means to optimize working methods.Peer reviewe

Investigation on the potential of improvement in the field of medical applications of ionizing radiation via the future European Metrology Network

Due to constant development in radiodiagnostic and radiotherapy procedures with increasing complexity, a need for high-level coordination of the ionizing radiation metrology community was recognized to better respond to the needs of end users. In order to facilitate knowledge dissemination and improve communication between stakeholders involved in medical applications of ionizing radiation, a Joint Network Project was started in 2020. One of the specific objectives of Work Package 2 of the project 19NET04 MIRA, “Support for a European Metrology Network on the medical use of ionizing radiation” is to support the developing states, ensuring that the planned EMN is inclusive through improvements in the medical use of ionizing radiation [1]. Czech Republic, Romania and Serbia were defined as countries of interest to conduct the survey and collect relevant data from stakeholders in the category of medical staff and professionals, so that the potential for improvement for medical applications of ionizing radiation can be evaluated. For the purpose of data collection, an online questionnaire was prepared and distributed to the stakeholders. The questionnaire was structured in such a way to allow easier collection of information regarding availability of (1) calibration services; (2) documented technical protocols; (3) standard documentation in the establishments for different ionizing radiation applications. Implementation of a Quality assurance (QA) programme was investigated, as well as the consistency in realization of proficiency testing (PT) or audits. The stakeholders were asked if additional workshops or training programmes are needed in their area of expertise. The radiodiagnostic modalities included in the questionnaire were the general radiography, mammography, computed tomography and interventional procedures, while radiotherapy modalities included external beam radiotherapy (teletherapy) and brachytherapy. Although nuclear medicine (therapy and diagnostic) procedures were part of the questionnaire, none of the respondents have capabilities for these applications. Based on the information collected via the online questionnaire, calibration services are available for most of the modalities, except for brachytherapy where traceability is not established. QA and PT are regularly performed in radiotherapy, while it is not the case in radiodiagnostic modalities. Improvement in knowledge transfer is needed for all of the applications investigated. Considering the acquired information, there is a clear need for EMN to support knowledge transfer, communication and technical exchange between the metrology community and the stakeholders involved in the medical applications of ionizing radiation. The forthcoming European Metrology Network will further elaborate the knowledge dissemination and stakeholder dialogue through its stakeholder panels and joint training effortsX JUBILEE International Conference on Radiation in Various Fields of Research : RAD 2022 (Spring Edition) : book of abstracts; June 13-17, 2022; Herceg Novi, Montenegr

GuideRadPROS: Updating the basis of radiation protection dosimetry by harmonization, update and implementation of standards

Purpose: The recent update of the ISO 4037, in conjunction with the new radiation protection quantities introduced in ICRU Report 95, present significant challenges to calibration laboratories and industry. Furthermore, there is a need to address gaps and conflicts between standards that set requirements for photon dosimeters, and to incorporate upcoming and new technologies into standardization. Materials and Methods: The European Partnership Project 23NRM07 GuideRadPROS started in June 2023 and will address these issues in the next three years. The objectives are: • to develop harmonized X-ray spectrometry in accordance with the ISO 4037 standard series, evaluate discrepancies between measured and calculated half value layer of X-ray spectra, and produce data to update requirements for reference X-ray fields. • to develop guidance for the calibration of dosimeters. • to produce guidance on validated procedures for harmonized type testing based on IEC standards. • to assess future standardization needs and to produce a guidance document for the implementation of the new operational quantities of ICRU Report 95 into standards and regulations. • to collaborate with ISO and IEC and users of their dosimetry standards to ensure that project outputs align with their needs. Results: The outcome of this project will lead to improved and comparable procedures in calibration and type testing within Europe. Furthermore, the evaluation of the impact of the ICRU Report 95 quantities will allow for an informed realization of calibration fields. Conclusions: GuideRadPROS will improve the confidence in radiation protection dosimetry, both via the promotion of the implementation of the ISO 4037 standard series, and via the assessment of the impact of the ICRU Report 95 operational quantities on daily measurements in radiation protection.ERPW 2023 - European Radiation Protection Week, 9-13th October 2023, Dublin, Irelan

Multispectral photon-counting for medical imaging and beam characterization - A project review

Central focus of the MPMIB project – funded via the Academy of Finland’s RADDESS 2018–2021 programme – has been research towards a next-generation radiation detection system operating in a photon-counting (PC) multispectral mode: The extraction of energy spectrum per detector pixel data will lead to better efficacy in medical imaging with ionizing radiation. Therefore, it can be an important asset for diagnostic imaging and radiotherapy, enabling better diagnostic outcome with lower radiation dose as well as more versatile characterization of the radiation beam, leading for example to more accurate patient dosimetry. We present our approach of fabricating direct-conversion detectors based on cadmium telluride (CdTe) semiconductor material hybridized with PC mode capable application-specific integrated circuits (ASICs), and will give a review on our achievements, challenges and lessons learned. The CdTe crystals were processed at Micronova, Finland’s national research infrastructure for micro- and nanotechnology, employing techniques such as surface passivation via atomic layer deposition, and flip chip bonding of processed sensors to ASIC. Although CdTe has excellent photon radiation absorption properties, it is a brittle material that can include large concentrations of defects. We will therefore also emphasize our quality assessment of CdTe crystals and processed detectors, and present experimental data obtained with prototype detectors in X-ray and Co-60 beams at a standards laboratoryPeer reviewe

Recommendations for the use of active personal dosemeters (APDs) in interventional workplaces in hospitals

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, with APDs used for real-time readings, for training purposes and when new imaging technology is introduced. However, there are limitations when using APDs. A survey in hospitals to identify issues related to the use of APDs was recently completed, along with an extensive series of APD tests by the EURADOS Working Group 12 on Dosimetry for Medical Imaging. The aim of this review paper is to summarise the state of the art regarding the use of APDs. We also used the results of our survey and our tests to develop a set of recommendations for the use of APDs in the clinical interventional radiology/cardiology settings, and draw attention to some of the current challenges

Contemporary radiation doses in interventional cardiology: a nationwide study of patient doses in Finland

The amount of interventional procedures such as percutaneous coronary intervention (PCI), transcatheter aortic valve implantation (TAVI), pacemaker implantation (PI) and ablations has increased within the previous decade. Simultaneously, novel fluoroscopy mainframes enable lower radiation doses for patients and operators. Therefore, there is a need to update the existing diagnostic reference levels (DRLs) and propose new ones for common or recently introduced procedures. We sought to assess patient radiation doses in interventional cardiology in a large sample from seven hospitals across Finland between 2014 and 2016. Data were used to set updated national DRLs for coronary angiographies (kerma-air product (KAP) 30 Gycm2) and PCIs (KAP 75 cm2), and novel levels for PIs (KAP 3.5 Gycm2), atrial fibrillation ablation procedures (KAP 25 Gycm2) and TAVI (KAP 90 Gycm2). Tentative KAP values were set for implantations of cardiac resynchronization therapy devices (CRT, KAP 22 Gycm2), electrophysiological treatment of atrioventricular nodal re-entry tachycardia (6 Gycm2) and atrial flutter procedures (KAP 16 Gycm2). The values for TAVI and CRT device implantation are published for the first time on national level. Dose from image acquisition (cine) constitutes the major part of the total dose in coronary and atrial fibrillation ablation procedures. For TAVI, patient weight is a good predictor of patient dose.</p