Search results for "IONIZING-RADIATION"
showing 4 items of 4 documents
A Cohort Study of Childhood Cancer Incidence after Postnatal Diagnostic X-Ray Exposure
2009
Ionizing radiation is an established cause of cancer, yet little is known about the health effects of doses from diagnostic examinations in children. The risk of childhood cancer was studied in a cohort of 92.957 children who had been examined with diagnostic X rays in a large German hospital during 1976-2003. Radiation doses were reconstructed using the individual dose area product and other exposure parameters, together with conversion coefficients developed specifically for the medical devices and standards used at the radiology department. Newly diagnosed cancers occurring between 1980 and 2006 were determined through record linkage to the German Childhood Cancer Registry. The median ra…
EPI-CT: design, challenges and epidemiological methods of an international study on cancer risk after paediatric and young adult CT
2015
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, coor…
The use of theranostic gadolinium-based nanoprobes to improve radiotherapy efficacy
2014
International audience; A new efficient type of gadolinium-based theranostic agent (AGuIX) has recently been developed for magnetic resonance imaging (MRI)-guided radiotherapy. These new particles consist of a polysiloxane network surrounded by a number of gadolinium chelates, usually 10. Due to their small size (<5 nm), AGuIX typically exhibit biodistributions that are almost ideal for diagnostic and therapeutic purposes. For example, while a significant proportion of these particles accumulate in tumours, the remainder is rapidly eliminated by the renal route. In addition, these particles present no evidence of toxicity, in the absence of irradiation with up to 10 times the planned dose f…
Lack of correlation between apoptosis and DNA single-strand breaks in X-irradiated human peripheral blood mononuclear cells in the course of ageing
1998
The dependence on age of both the basal and the X-radiation-induced levels of apoptosis was examined in human peripheral blood mononuclear cells (PBMC). In the same samples, the base value and the extent of induced DNA single-strand breaks were determined, using a sensitive and fast microplate assay. PBMC were isolated from blood of donors of various age groups (20-30, 40-60 and > 70 years of age) and X-irradiated ex vivo using a 6 MV linear accelerator to give a total exposure of 4 Gy. The mean basal levels of apoptosis in PBMC from donors in the 40-60 year age group and the > 70 year age group were found to be only slightly higher (by 20-10%) compared to that of the 20-30 year age group, …