[en] 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, the second approach focuses on the conversion of the individual whole-body dose to eye lens dose. In contrast with usual dose reconstruction methods within an epidemiological study, a protocol is applied resulting in an individual distribution of possible cumulative lens doses for each recruited cardiologist, rather than a single dose estimate. In this way, the uncertainty in the dose estimate (from measurement uncertainty and variability among cardiologists) is represented for each individual. Eye lens dose and whole-body dose measurements have been performed in clinical practice to validate both methods, and it was concluded that both produce acceptable results in the framework of a dose-risk evaluation study. Optimal results were obtained for the dose to the left eye using procedure-specific lens dose data in combination with information collected on working practice. This method has been applied to 421 interventional cardiologists resulting in a median cumulative eye lens dose of 15.1 cSv for the left eye and 11.4 cSv for the right eye. From the individual cumulative eye lens dose distributions obtained for each cardiologist, maxima up to 9-10 Sv were observed, although with low probability. Since whole-body dose values above the lead apron are available for only a small fraction of the cohort and in many cases not for the entire working career, the second method has only been used to benchmark the results from the first approach. This study succeeded in improving the retrospective calculation of cumulative eye lens doses in the framework of radiation-induced risk assessment of lens opacities, but it remains dependent on self-reported information, which is not always reliable for early years. However, the calculation tools developed can also be used to make an assessment of the eye lens dose in current practice.

[en] 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. Methods: Gafchromic (R) films and thermoluminescent dosimeters (TLD) were used to determine the Maximum Skin Dose (MSD). Correlation of the online dose indicators (fluoroscopy time, kerma- or dose-area product (KAP or DAP) and cumulative air kerma at interventional reference point (K-a,K-r)) with MSD was evaluated and used to establish the alert levels corresponding to a MSD of 2 Gy and 5 Gy. The uncertainties of alert levels in terms of DAP and K-a,K-r, and uncertainty of MSD were calculated. Results: About 20-30% of all MSD values exceeded 2 Gy while only 2-6% exceeded 5 Gy. The correlations suggest that both DAP and K-a,K-r can be used as a dose indicator for alert levels (Pearson correlation coefficient p mostly > 0.8), while fluoroscopy time is not suitable (p mostly < 0.6). Generic alert levels based on DAP (Gy cm(2)) were suggested for MSD of both 2 Gy and 5 Gy (for 5 Gy: TACE 750, PCI 250 and NE 400). The suggested levels are close to the lowest values published in several other studies. The uncertainty of the MSD was estimated to be around 10-15% and of hospital-specific skin dose alert levels about 20-30% (with coverage factor k = 1). Conclusions: The generic alert levels are feasible for some cases but should be used with caution, only as the first approximation, while hospital-specific alert levels are preferred as the final approach.

[en] 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 interventional rooms) and for 10 different procedures. Dose data was collected from a total of 14,922 interventional cardiology procedures. Based on these data European diagnostic reference levels (DRL) for air kerma-area product are suggested for coronary angiography (CA, DRL = 35 Gy cm2), percutaneous coronary intervention (PCI, 85 Gy cm2), transcatheter aortic valve implantation (TAVI, 130 Gy cm2), electrophysiological procedures (12 Gy cm2) and pacemaker implantations. Pacemaker implantations were further divided into single-chamber (2.5 Gy cm2) and dual chamber (3.5 Gy cm2) procedures and implantations of cardiac resynchronization therapy pacemaker (18 Gy cm2). Results show that relatively new techniques such as TAVI and treatment of chronic total occlusion (CTO) often produce relatively high doses, and thus emphasises the need for use of an optimization tool such as DRL to assist in reducing patient exposure. The generic DRL presented here facilitate comparison of patient exposure in interventional cardiology. © 2018 Associazione Italiana di Fisica Medica

[en] This study aimed to investigate the level of the eye lens (EL) doses in nuclear medicine in the light of the new International Commission on Radiological Protection limit. In 7 Belgian and 1 Polish hospitals, 45 staff members were monitored for EL (H_p(3)) and whole-body (WB) (H_p(10)) doses using dedicated dosemeters. Weekly measurements were carried out and used to estimate annual doses. Mostly diagnostic procedures involving radionuclides such as "9"9"mTc and "1"8F were monitored; measurements were also performed for therapeutic procedures. The cumulative doses showed important variation across the participants. The weekly EL and WB doses ranged from 0.02 to 0.27 and 0.03 to 0.17 mSv, respectively; the annual EL and WB doses ranged from 0.6 to 9.3 and 0.9 to 8.0 mSv, respectively. Some correlation was found between the EL and the WB doses. No significant correlation with the manipulated activities was found. (authors)

[en] This paper aims to validate the accuracy of the peak skin dose (D_skin,max) computed by the Dose Map software (DMS)-General Electric and establish a local follow-up protocol for the management of patient skin injuries following complex interventional cardiology procedures (ICPs). D_skin,max was computed by the DMS and was simultaneously measured by a dense mesh of 72 thermoluminescent dosemeters for 20 ICP. Measured and computed D_skin,max were compared using Lin's concordance coefficient (ρ_c). The implementation of a local follow-up strategy was based on a computed D_skin,max of 2 Gy. After eliminating 2 outliers, the average deviation between the two methods was 6% (range: -36 to +40%). Concordance between the two methods was moderate with ρ_c (confidence interval) of 0.9128 (0.8541-0.9486). DMS computes D_skin,max with an acceptable accuracy and can be used to setup an individual follow-up process for patients with high skin exposure and risks. (authors)

[en] Percutaneous coronary interventions (PCI) of coronary chronic total occlusions (CTO) increase the risk of high radiation exposure for both the patient and the cardiologist. This study evaluated the maximum dose to the patients' skin (MSD) and the exposure of the cardiologists during CTO-PCI. Moreover, the efficiency of radioprotective drapes to reduce cardiologist exposure was assessed. Patient dose was measured during 31 procedures; dose to the cardiologist's extremities were measured during 65 procedures, among which 31 were performed with radioprotective drapes. The MSD was high (median: 1254 mGy; max: 6528 mGy), and higher than 2 Gy for 33% of the patients. The dose to the cardiologists' extremities per procedure was also of concern (median: 25-465 μSv), particularly to the left eye (median: 68 μSv; max: 187 μSv). Radioprotective drapes reduced the exposure to physician's upper limbs and eyes; especially to the left side (from -28 to -49%). (authors)

[en] The use of ionising radiation (IR) for medical diagnosis and treatment procedures has had a major impact on the survival of paediatric patients. Although the benefits of these techniques largely outweigh the risks, the evidence to date suggests that children are more sensitive than adults to the carcinogenic effects of IR. Therefore, there is a need to better understand the long-term health effects of such exposures in order to optimise treatment in these young patients and reduce the risk of late toxicities. HARMONIC aims to improve our understanding of the health effects of exposure to medical IR in children, specifically cancer patients treated with modern radiotherapy techniques, and cardiac patients treated with cardiac fluoroscopy procedures (CFP). HARMONIC also develops dosimetric data collection software tools to allow dose reconstruction in both CFP and radiotherapy. The project builds on a multi-disciplinary collaboration to investigate long-term outcomes (endocrine dysfunction, cardiovascular and neurovascular damage, quality of life (QoL) and social impacts, and secondary cancers) of paediatric cancer patients after the application of modern radiotherapy modalities. Instruments for harmonised demographic, clinical and dosimetric data collection were defined serving as a pilot phase for a future pan-European registry. The cardiac component of HARMONIC builds a pooled cohort of approximately 100,000 patients who underwent CFP in 7 countries, while aged under 22 years. The cohort, based on data collection from hospital records and/or insurance claims data, will be followed-up using national registries and insurance records to determine vital status and cancer incidence. Where available, information on organ transplantation (a major risk factor for cancer development in this patient group) and/or other conditions predisposing to cancer will be obtained from national or local registries and health insurance data. The relationship between estimated radiation dose and cancer risk will be investigated using regression modelling. With its prospective design and the creation of a biobank for the collection of biological samples, HARMONIC also aims at providing a mechanistic understanding of radiation-induced adverse health effects and identify potential biomarkers indicative of vascular adverse effects and secondary cancer. These biomarkers could ultimately contribute to early diagnosis, treatment and prevention of adverse effects. (authors)