EPI-CT: design, challenges and epidemiological methods of an international study on cancer risk after paediatric and young adult CT

Computed tomography (CT) has great clinical utility and its usage has increased dramatically over the years. Concerns have been raised, however, about health impacts of ionising radiation exposure from CTs, particularly in children, who have a higher risk for some radiation induced diseases. Direct estimation of the health impact of these exposures is needed, but the conduct of epidemiological studies of paediatric CT populations poses a number of challenges which, if not addressed, could invalidate the results. The aim of the present paper is to review the main challenges of a study on the health impact of paediatric CTs and how the protocol of the European collaborative study EPI-CT, coordinated by the International Agency for Research on Cancer (IARC), is designed to address them. The study, based on a common protocol, is being conducted in Belgium, Denmark, France, Germany, the Netherlands, Norway, Spain, Sweden and the United Kingdom and it has recruited over one million patients suitable for long-term prospective follow-up. Cohort accrual relies on records of participating hospital radiology departments. Basic demographic information and technical data on the CT procedure needed to estimate organ doses are being abstracted and passive follow-up is being conducted by linkage to population-based cancer and mortality registries. The main issues which may affect the validity of study results include missing doses from other radiological procedures, missing CTs, confounding by CT indication and socioeconomic status and dose reconstruction. Sub-studies are underway to evaluate their potential impact. By focusing on the issues which challenge the validity of risk estimates from CT exposures, EPI-CT will be able to address limitations of previous CT studies, thus providing reliable estimates of risk of solid tumours and leukaemia from paediatric CT exposures and scientific bases for the optimisation of paediatric CT protocols and patient protection

Uncertainties involved in the estimation of mean glandular dose for women in the Norwegian breast cancer screening program (NBCSP)

The aim of this study was to reflect on the estimation of the mean glandular dose for women in Norway aged 50–69 y. Estimation of mean glandular dose (MGD) has been conducted by applying the method of Dance et al. (1990, 2000, 2009). Uncertainties in the thickness of approximately ±10 mm adds uncertainties in the MGD of approximately ±10 %, and uncertainty in the glandularity of ±0 % will lead to an uncertainty in the MGD of ±4 %. However, the inherent uncertainty in the air kerma, given by the European protocol on dosimetry, will add an uncertainty of 12 %. The total uncertainty in the MGD is estimated to be ∼20 %, taking into consideration uncertainties in compressed breast thickness (±10 %), the air kerma (12 %), change in HVL by −0.05 mm (−9.0 %), uncertainty in the s-factor of ±2.1 % and changing the glandularity to an age-dependent glandularity distribution (+8.4 %)

Impact of mobile radiography services in nursing homes on the utilisation of diagnostic imaging procedures

Background:In the last decade, mobile radiography services have been introduced in nursing homes in severalcountries. Earlier research found an underutilisation of diagnostic imaging among nursing home residents.However, the effects of introducing mobile radiography services on the use of diagnostic imaging are unknown.The purpose of this study was to determine the utilisation of diagnostic imaging among nursing home residentsand if there are any differences between hospitals with and without a mobile radiography service.Methods:Data for 2015 were collected from the radiological information systems of 11 hospitals. The dataincluded information on the anatomical region/organ/organ system, modality, and information on where theexamination took place. Using nursing home beds as a proxy for nursing home residents’differences in the use ofdiagnostic imaging in areas with hospitals with and without mobile radiography services were analysed. The chi-squared test was used to compare the areas.Results:From 11,066 examinations of nursing home residents, 87% were plain radiographs, 8% were CT scans, and4% were ultrasound examinations. In areas with mobile radiography services, there was a significantly higherproportion of diagnostic imaging used per nursing home bed, 50% per bed compared to 36% per bed in areaswithout;p=< 0.001. Furthermore, in areas with mobile radiography services, there was a significantly lowerproportion of CT and ultrasound used per nursing home bed, 2.5 and 1.4% respectively per bed compared to4.7 and 2.2% respectively per bed in areas without;p=< 0.001.Conclusions:This study demonstrate a lower use of radiology by nursing home residents compared to the generalpopulation, and indicates that mobile radiography services increase the level closer to the user rate in the generalpopulation. The proportions of plain radiographs are significantly higher in areas with a mobile radiography service,while the proportion of more advanced imaging techniques such as CT and ultrasound are lower. The higher useof diagnostic imaging is most likely appropriate because of higher morbidity and lower use of diagnostic imagingamong nursing home residents, compared to the general population. Further research is necessary on how toimprove diagnostic imaging services for nursing home residents

The use of 80 kV versus 100 kV in pulmonary CT angiography: An evaluation of the impact on radiation dose and image quality on two CT scanners

Introduction Use of CT in the investigation of pulmonary embolism in radiosensitive patients such as pregnant and young female patients entails the need for protocol optimization. The aim of this study was to analyze the dose reduction and image quality achieved by using 80 kV instead of 100 kV in CT pulmonary angiography protocols. Methods 80 examinations of non-obese patients were analyzed (40 consecutive patients for each protocol, equally distributed on two CT scanners). Objective image quality was assessed by measurements of HU values (average and standard deviation) in five ROIs in pulmonary arteries and calculations of signal-to-noise (SNR) and contrast-to-noise ratios (CNR). Subjective image quality was independently evaluated by two radiologists in terms of perceived noise, sharp reproduction of pulmonary arteries and overall diagnostic quality. Radiation dose parameters (CTDIvol, DLP, SSDE and effective dose) and effective risk were compared. Differences in radiation dose and objective measures of image quality for the two protocols were assessed using the independent t test; comparison of subjective grading of image quality was performed with the Mann–Whitney U test. Results Use of 80 kV significantly increased both arterial contrast enhancement and image noise. Differences in SNR and CNR between protocols were not statistically significant. Achieved dose reduction by using 80 kV was significant on both scanners (SSDE reduction 35% and 46%, p < 0.001; effective dose reduction 40% and 53%, p < 0.001). Conclusion Use of 80 kV protocols for CT examinations of pulmonary arteries in non-obese patients with bodyweight below 80 kg results in significant reduction of radiation doses without compromising image quality

Cost analysis of mobile radiography services for nursing home residents in Southeast Norway

Rationale, aims, and objective Telemedicine applications, such as a mobile radiography service, provide a new way of organizing healthcare services. In order to provide safe and personalised care for nursing home residents during X‐ray examinations, mobile radiography services have been implemented. The objective of this study was to analyse the costs of X‐ray examinations and treatments for nursing home residents when comparing hospital‐based imaging with a combination of hospital‐based imaging and a mobile radiography service in Southeast Norway. Methods A decision model was developed using the software TreeAge Pro. The model included two alternatives: the mobile radiography service in combination with hospital‐based imaging and hospital‐based imaging alone. The treatment needed based on the examination results could be given either in the nursing home or at the hospital. Probabilities and costs in the model were derived from previous research, various reports, and hospital data from the Southeast region of Norway. Monte Carlo simulations of 1000 residents were run through the model, and statistical analyses were applied. Results The analysis showed a mean cost of €2790 per resident for the hospital‐based service alone. For mobile and hospital‐based services combined, the mean cost was €1946 per resident, including examinations and the immediate treatment given. This difference in costs was significant (p < 0.001). Conclusion A mobile radiography service in nursing homes provides a safe, high quality health care service. The result of this study showed there was a 30% cost‐reduction by implementing the mobile radiography servic

Managers’ experience of success criteria and barriers to implementing mobile radiography services in nursing homes in Norway: a qualitative study

Abstract Background In order to meet the future challenges posed by ageing populations, new technology, telemedicine and a more personalized healthcare system are needed. Earlier research has shown mobile radiography services to be highly beneficial for nursing home residents in addition to being cost-effective. Despite the benefits, mobile radiography services are uncommon in Europe and Norway. The purpose of this study was to explore success criteria and barriers in the process of implementing mobile radiography services, from the point of view of the hospital and municipal managers. Methods Eleven semi-structured interviews were conducted with managers from five hospitals and six municipalities in Norway where mobile radiography services had been implemented. Core issues in the interview guide were barriers and facilitators in the different phases of implementation. The framework method for thematic analysis was used for analysing the data inductively in a research team. Results Five main categories were developed through the success criteria and barriers experienced by the participants: national health policy, regional and municipal policy and conditions, inter-organizational implementation projects, experienced outcome, and professional skills and personal characteristics. The categories were allocated into three higher-order classifications: macro, meso and micro levels. The main barriers experienced by the managers were financial, procedural and structural. In particular, the reimbursement system, lack of management across healthcare levels and the lack of compatible information systems acted as barriers. The main facilitators were external funding, enthusiastic individuals in the organizations and good collaboration between hospitals and municipalities. Conclusions The managers experienced financial, structural and procedural barriers. The main success criteria in the process were external funding, and the support and engagement from the individuals in the organizations. This commitment was mainly facilitated by the intuitive appeal of mobile radiography. Changes in healthcare management and in the financial system might facilitate services across healthcare levels. In addition, compatible information systems across healthcare levels are needed in order to facilitate the use of new technology and mobile services

Patient doses from screen-film and full-field digital mammography in a population-based screening programme

The aim of this study was to compare mean glandular dose (MGD) in all full-field digital mammography (FFDM) and screen film mammography (SFM) systems used in a national mammography screening program. MGD from 31 screening units (7 FFDM and 24 SFM), based on an average of 50 women at each screening unit, representing 12 X-ray models (6 FFDM and 6 SFM) from five different manufacturers were calculated. The MGD was significantly lower for FFDM compared with SFM (craniocaudal): 1.19 versus 1.27 mGy, respectively, mediolateral oblique: 1.33 versus 1.45 mGy, respectively), but not all of the FFDM units provided lower doses than the SFM units. Comparing FFDMs, the photon counting scanning-slit technology provides significantly lower MGDs than direct and indirect conversion digital technology. The choice of target/filter combination influences the MGD, and has to be optimised with regard to breast thickness

Radiographers' assessment of referrals for CT and MR imaging using a web-based data collection tool

Introduction: There is limited research related to the radiographers' role in assessing of radiology referrals to justify imaging. This study investigated radiographers' compliance with guidelines in the assessment of CT and MRI referrals and factors that influenced their performance. Methods: This research was facilitated by the EFRS Research Hub at ECR 2019. Five radiology referral scenarios for CT and/or MRI were distributed to radiographers, as determined by their scope of practice, who volunteered at the Research Hub. A web-based data collection tool was used. The radiographers were required to determine the appropriateness of each referral, highlight any concerns and recommend suitable investigations if applicable. Linear regression analysis was used to determine whether postgraduate qualification, grade/role of the radiographer and use of guidelines influenced the radiographers' performance in assessing the referrals. Results: Participants originated from 24 countries (n = 51 CT, n = 40 MRI), the majority originating from the UK, Ireland, Italy, Spain, Norway and Austria. Responses consistent with guidelines were 58% and 57% for CT and MRI, respectively. Possession of an MSc qualification in CT was a significant factor of influence for a higher consistency with guidelines (p = 0.02) in CT. Employment as a radiographer in a lead professional role and/or educator was a significant factor of influence for a higher consistency with guidelines in MRI (p = 0.01). Conclusion: A total of 58% for CT and 57% for MRI of the radiographers' responses complied with guidelines. Factors such as postgraduate education and leading professional roles are associated with better performance. Implications for practice: Considering qualifications, experience and managerial role is vital before radiographers are delegated task of justifying CT and MR Imaging

Assessing Organ Doses from Paediatric CT Scans—A Novel Approach for an Epidemiology Study (the EPI-CT Study)

The increasing worldwide use of paediatric computed tomography (CT) has led to increasing concerns regarding the subsequent effects of exposure to radiation. In response to this concern, the international EPI-CT project was developed to study the risk of cancer in a large multi-country cohort. In radiation epidemiology, accurate estimates of organ-specific doses are essential. In EPI-CT, data collection is split into two time periods—before and after introduction of the Picture Archiving Communication System (PACS) introduced in the 1990s. Prior to PACS, only sparse information about scanner settings is available from radiology departments. Hence, a multi-level approach was developed to retrieve information from a questionnaire, surveys, scientific publications, and expert interviews. For the years after PACS was introduced, scanner settings will be extracted from Digital Imaging and Communications in Medicine (DICOM) headers, a protocol for storing medical imaging data. Radiation fields and X-ray interactions within the body will be simulated using phantoms of various ages and Monte-Carlo-based radiation transport calculations. Individual organ doses will be estimated for each child using an accepted calculation strategy, scanner settings, and the radiation transport calculations. Comprehensive analyses of missing and uncertain dosimetry data will be conducted to provide uncertainty distributions of doses