Factors affecting implementation of radiological protection aspects of imaging in radiotherapy

Dramatic improvements in radiotherapy equipment have allowed radiation fields to be conformed to tumours for more accurate treatment. Successful delivery often requires imaging at every treatment fraction, a method known as image guided radiation therapy (IGRT). But increased X-ray imaging exposes patients to doses that carry risks of inducing second cancers in normal tissues. Therefore, reductions in high-dose treatment margins achieved with IGRT must be balanced against detriments from greater imaging doses. ICRP Task Group 116 has been set up to prepare guidance on radiological protection aspects of IGRT. Factors affecting the optimization of radiological protection are the modalities used, the frequency of imaging, the image acquisition parameters influencing image quality and radiation dose, and the volume of normal tissue included in the images. The Task Group has undertaken two projects: (1) a snapshot survey of radiotherapy imaging practices across six continents, which has shown that use of kV cone beam CT (CBCT) increases with Human Development Index for the country; and (2) a project looking at ways for measuring CBCT doses that could be applied more widely. The results highlight the need for raising awareness of imaging doses, and development of the dose quantities displayed on imaging equipment used in radiotherapy

Patient dose monitoring and the use of diagnostic reference levels for the optimization of protection in medical imaging: current status and challenges worldwide

Optimointi on yksi säteilysuojelun pääkäsitteistä radiologisessa kuvantamisessa. Käytännössä se tarkoittaa sitä, että potilaan saama säteilyannos ei saisi olla suurempi kuin mitä tarvitaan, jotta saavutetaan halutun diagnostisen informaation tuottava kuvan laatu. Potilaan säteilyannoksen määrittäminen on siten edellytyksenä optimoinnin toteuttamiselle. Kansainvälinen säteilysuojelutoimikunta (ICRP) on suositellut potilaan säteilyaltistuksen vertailutasoja optimoinnin käytännön työkaluksi. Vertailutasoja ei kuitenkaan ole sovellettu kaikissa maissa yhtenäisellä tavalla. Kansainvälinen atomienergiajärjestö (IAEA) järjesti aihepiiriä käsitelleen teknisen kokouksen toukokuussa 2016, tarkoituksena kartoittaa nykyiset heikkoudet ja vahvuudet vertailutasojen käytössä ja optimoinnissa, sekä edistää tarpeellisten parannusten aikaan saantia. Tässä julkaisussa esitetään yhteenveto kokouksessa saadusta tilannekuvasta ja tehdyistä johtopäätöksistä. Vahvuudet ja heikkoudet olivat osittain erilaisia kehittyneissä maissa verrattuna kehitysmaihin. Parannustarpeita arvioitiin olevan kuudessa aihepiirissä: henkilöresurssit ja vastuujärjestelyt, koulutus, turvallisuus- ja laatukulttuuri, säännöstö, rahoitus ja laitteet ja menetelmät. Viimeksi mainittuun ryhmään kuului useita osa-alueita, mm. radiologisten tutkimusten luokittelu (nimikkeistöt), vertailutasojen käyttöstrategia sekä integroitu ja automaattinen tiedonhallinta. Yleisenä johtopäätöksenä todettiin, että säteilysuojelun tulisi olla potilaskeskeistä ja olisi siirryttävä enemmän reaktiivisesta optimoinnista proaktiiviseen (ennakoivaan) optimointiin. Paras lopputulos saavutetaan hyvällä tiimityöllä

Accounting for radiation exposure from previous CT exams while deciding on the next exam: What do referring clinicians think?

© 2022 Elsevier B.V.Purpose: To obtain clinicians’ views of the need to account for radiation exposure from previous CT scans and the advisability of a regulatory mechanism to control the number of CT scans for an individual patient. Methods: A convenience survey was conducted by emailing a link to a three-question electronic survey to clinicians in many countries, mostly through radiology and radiation protection contacts. Results: 505 responses were received from 24 countries. 293 respondents (58%) understand that current regulations do not limit the number of CT scans that can be prescribed for a single patient in a year. When asked whether there should be a regulation to limit the number of CT scans that can be prescribed for a single patient in one year, only a small fraction (143, 28%) answered ‘No’, 182 (36%) answered ‘Maybe’ and 166 (33%) answered ‘Yes’. Most respondents (337; 67%) think that radiation risk should form part of the consideration when deciding whether to request a CT exam. A minority (138; 27%) think the decision should be based only on the medical indication for the CT exam. Comparison among the 4 countries (South Korea, Hungary, USA and Canada) with the largest number of respondents indicated wide variations in responses. Conclusions: A majority of the surveyed clinicians consider radiation risk, in addition to clinical factors, when prescribing CT exams. Most respondents are in favor of, or would consider, regulation to control the number of CT scans that could be performed on a patient annually.N

National survey to set diagnostic reference levels in nuclear medicine single photon emission imaging in Croatia

Purpose: In order to introduce the concept of diagnostic reference levels (DRLs) in the national nuclear medicine practice a survey was proposed and completed through all nuclear medicine departments in Croatia. An additional aim was to increase the awareness of importance and full implementation of a comprehensive quality program that includes devices used in the nuclear medicine chain. Methods: Data were collected for more than 30 nuclear medicine single photon emission procedures. National DRLs (NDRLs) as administered activity and also as administered activity per unit mass were calculated in accordance to International Commission on Radiological Protection (ICRP) recommendations. Additionally, effective doses were estimated using conversion factors published by the ICRP. Results: NDRLs for nuclear medicine single photon emission procedures were proposed. For procedures performed in only one department typical values were presented as reference. Effective doses related to applied radiopharmaceuticals were calculated to estimate radiation risk related to respective nuclear medicine procedure in more detail. Conclusion: This work presents results of the first national survey on DRLs of nuclear medicine single photon emission procedures and proposes reliable NDRLs that represent an actual status of nuclear medicine practice in Croatia. Results have motivated departments to introduce and set their own typical values to be used, as one of the tools, for further optimization process. One of the drawbacks of the DRL concept in nuclear medicine is the lack of the image quality parameters involved. For this reason, a quantity that considers both radiation protection and image quality should be introduced

Accounting for radiation exposure from previous CT exams while deciding on the next exam: What do referring clinicians think?

Purpose: To obtain clinicians’ views of the need to account for radiation exposure from previous CT scans and the advisability of a regulatory mechanism to control the number of CT scans for an individual patient. Methods: A convenience survey was conducted by emailing a link to a three-question electronic survey to clinicians in many countries, mostly through radiology and radiation protection contacts. Results: 505 responses were received from 24 countries. 293 respondents (58%) understand that current regulations do not limit the number of CT scans that can be prescribed for a single patient in a year. When asked whether there should be a regulation to limit the number of CT scans that can be prescribed for a single patient in one year, only a small fraction (143, 28%) answered ‘No’, 182 (36%) answered ‘Maybe’ and 166 (33%) answered ‘Yes’. Most respondents (337; 67%) think that radiation risk should form part of the consideration when deciding whether to request a CT exam. A minority (138; 27%) think the decision should be based only on the medical indication for the CT exam. Comparison among the 4 countries (South Korea, Hungary, USA and Canada) with the largest number of respondents indicated wide variations in responses. Conclusions: A majority of the surveyed clinicians consider radiation risk, in addition to clinical factors, when prescribing CT exams. Most respondents are in favor of, or would consider, regulation to control the number of CT scans that could be performed on a patient annually. © 2022 Elsevier B.V

Recurrent medical imaging exposures for the care of patients:one way forward

Medical imaging is both valuable and essential in the care of patients. Much of this imaging depends on ionizing radiation with attendant responsibilities for judicious use when performing an examination. This responsibility applies in settings of both individual as well as multiple (recurrent) imaging with associated repeated radiation exposures. In addressing the roles and responsibilities of the medical communities in the paradigm of recurrent imaging, both the International Atomic Energy Agency (IAEA) and the American Association of Physicists in Medicine (AAPM) have issued position statements, each affirmed by other organizations. The apparent difference in focus and approach has resulted in a lack of clarity and continued debate. Aiming towards a coherent approach in dealing with radiation exposure in recurrent imaging, the IAEA convened a panel of experts, the purpose of which was to identify common ground and reconcile divergent perspectives. The effort has led to clarifying recommendations for radiation exposure aspects of recurrent imaging, including the relevance of patient agency and the provider-patient covenant in clinical decision-making. CLINICAL RELEVANCE STATEMENT: An increasing awareness, generating some lack of clarity and divergence in perspectives, with patients receiving relatively high radiation doses (e.g., ≥ 100 mSv) from recurrent imaging warrants a multi-stakeholder accord for the benefit of patients, providers, and the imaging community. KEY POINTS: • Recurrent medical imaging can result in an accumulation of exposures which exceeds 100 milli Sieverts. • Professional organizations have different perspectives on roles and responsibilities for recurrent imaging. • An expert panel reconciles differing perspectives for addressing radiation exposure from recurrent medical imaging.</p