Radiation doses and associated risks from x-ray guided cardiac catheterization procedures in children and young adults

PhD ThesisCardiac catheterizations are an essential procedure in the management of patients with congenital and acquired heart conditions. However, associated radiation doses are often high, raising concerns over potentially increased cancer risks. Neither the radiation doses, nor the associated risks, have been adequately investigated in young people undergoing these procedures. A cohort was established of around 13,500 patients aged under 22 years who have undergone cardiac catheterizations in England. Organ doses were estimated based on a dosimetry system utilising data from Monte Carlo simulations. Doses were highest for the lungs (median: 17.6 millisieverts, mSv) and heart (13.6 mSv), while doses to bone marrow (2.6 mSv) and the thyroid (0.7 mSv) were relatively low. Radiation doses have fallen by a factor of up to ten during the study period. The results were compared to equivalent figures derived from physical measurements. Uncertainties in dose estimates were calculated. These were around ±30%, though were potentially much higher for breast dose. The risk of cancer in relation to estimated doses was calculated using BEIR VII risk models. For examinations conducted using modern equipment, these risks are around 1 in 1700. A small epidemiological analysis was performed, suggesting a nearly threefold increased risk of cancer in the cohort, compared to the general UK population. There are a number of reasons to suggest that this increase was primarily not related to radiation exposure, most notably the large impact of transplantation and likely associated immunosuppressant use. Despite the high cancer incidence, the overall survival in the cohort was high, at around 91% after 30 years. Conclusion: The study provides the first large scale estimation of organ doses from cardiac catheterizations among this age group. Rates of cancer among this patient group are high, although this is appears to be mostly due to factors other than radiation exposure.British Heart Foundatio

Recent developments in the point wise neutron treatment for FLUKA v4

The present paper describes the new, original implementation of a point-wise neutron treatment that is made available with FLUKA v4.3-0 (https://fluka.cer

Radiological characterization for the disposal of a decommissioned LHC external beam dump at CERN

During the last Long Shutdown, a scheduled maintenance period between physics runs, the two Large Hadron Collider (LHC) beam dumps were replaced with upgraded spares modules. It was then decided to conduct an in-house autopsy and a post-irradiation examination of the removed dumps to extract information essential for the 3rd LHC physics run and to aid the design of new generations of beam dumps able to cope with future upgrades of the LHC. The need for a postmortem analysis of the dump cores opened the opportunity to combine the autopsy with processes required for the disposal of the dumps as radioactive waste at a dedicated disposal facility in France. This had a direct impact in terms of overall optimization of the interventions (postmortem analysis and prepackaging) to be performed on the dump as well as in terms of minimizing of the radiological risk (ALARA), by reducing the exposure of the personnel by combining two interventions in one. The characterization of the dump as radioactive waste was performed by means of state-of-the-art Monte Carlo and analytical techniques verified experimentally via a series of dedicated radiochemical (using liquid scintillation) analyses, conducted in-house and in external specialized laboratories. Based on these results, the dumps will be disposed of as intermediate–medium-level (FMA-VC) waste at the ANDRA CSA repository in France