Environmental conditions and variation in levels of sun exposure among children in child care

Sun exposure in childhood is 1 of the risk factors for developing skin cancer, yet little is known about levels of exposure at this age. This is particularly important in countries with high levels of ultraviolet radiation (UVR) such as Australia. Among 49 children 3 to 5 years of age attending child care centers, UVR exposure was studied under 4 conditions in a repeated measures design; sunny days, cloudy days, teacher’s instruction to stay in the shade, and a health professionals instruction to apply sunscreen. Three different data collection methods were employed: (a) completion of questionnaire or diary by parents and researcher, (b) polysulphone dosimeter readings, and (c) observational audits (video recording). Results of this study indicated that more than half the children had been sunburnt (pink or red) and more than a third had experienced painful sunburn (sore or tender) in the last summer. Most wore short sleeve shirts, short skirts or shorts and cap, that do not provide optimal levels of skin protection. However, sunscreen was applied to all exposed parts before the children went out to the playground. Over the period of 1 hr (9–10 a.m.) the average amount of time children spent in full sun was 22 min. On sunny days there was more variation across children in the amount of sun exposure received. While the potential amount of UVR exposure for young children during the hour they were outside on a sunny day was 1.45 MED (Minimum Erythemal Dose), they received on average 0.35 MED, which is an insufficient amount to result in an erythemal response on fair skin even without the use of sunscreen.     

A 2-year review of recent Nuclear Regulatory Commission events: What errors occur in the modern brachytherapy era?

PurposeTo perform a retrospective analysis of recently reported brachytherapy errors to the Nuclear Regulatory Commission and to compare with historical trends.MethodsAll events reported in the 2-year period from January 1, 2009 to December 31, 2010 were categorized and analyzed. The 4 main areas of dose delivery were Gamma Knife radiosurgery, therapeutic radiopharmaceutical administration, high-dose-rate brachytherapy, and low-dose-rate brachytherapy. The different types of errors were wrong site, wrong dose, unintended exposure, lost or leaking source, or other. The causes of events were specified as the following: communication errors, equipment malfunction, human error, lack of training, or miscellaneous.ResultsOne hundred and forty-seven events were found in the 2-year period. This error reporting rate far surpasses previous reports. The greatest number of events reported was for low-dose-rate brachytherapy, and the most common cause of error was human error. Wrong dose was the error that occurred most often, followed by wrong site.ConclusionsVery simple treatment errors, such as wrong patient, or wrong side of patient treated, are still occurring. Newer, complex deliveries such as high-dose-rate partial breast irradiation and low-dose-rate prostate brachytherapy also had a large number of events reported in this sampling. This report can help institutions establish needs for quality assessment and quality control processes.     

First TDCR measurements at low energies using a miniature x-ray tube

Developed for radionuclide standardization using liquid scintillation, the Triple to Double Coincidence Ratio (TDCR) method is applied using coincidence counting obtained with a specific three-photomultiplier system. For activity determination, a statistical model of light emission is classically used to establish a relation between the detection efficiency and the experimental TDCR value. At LNE-LNHB, a stochastic approach of the TDCR modeling was developed using the Monte Carlo code Geant4. The interest of this TDCR-Geant4 model is the possibility to simulate the propagation of optical photons from their creation in the scintillation vial to the production of photoelectrons in photomultipliers.As an alternative to the use of radionuclide sources, first TDCR measurements are presented using a miniature x-ray tube closely coupled to the scintillation vial. The objective of this new set-up was to enable low-energy depositions (lower than 20 keV) in liquid scintillator in order to study the influence of both time and geometrical dependence between PMTs already observed with radioactive sources. As for the statistical TDCR model, the non-linearity of light emission is implemented in the TDCR-Geant4 model using the Birks formula which depends on the kB factor and the scintillation yield. Measurements performed with the x-ray tube are extended to the assessment of these parameters and they are tested afterwards in the TDCR-Geant4 model for activity measurements of ³H.     

Preparation and first biological evaluation of novel Re-188/Tc-99m peptide conjugates with substance-P

IntroductionNew ¹⁸⁸Re and ^99mTc peptide conjugates with substance- P (SP) were prepared and biologically evaluated. The radiopharmaceuticals have been labelled with the [M≡N]²⁺ (M=^99mTc, ¹⁸⁸Re) core using a combination of π-donor tridentate and π-acceptor monodentate ancillary ligands.MethodsThe new radiopharmaceuticals have been prepared through a two-step reaction by simultaneous addition of the tridentate and monodentate ligands to a vial containing a preformed [M≡N]²⁺ core. The tridentate ligand was formed by linking two cysteine residues to the terminal arginine of the undecapeptide SP, whereas the monodentate ligand was a tertiary phosphine. The preparation of the corresponding Re-188 derivative required developing a more complex chemical procedure to obtain the [Re≡N]²⁺ core in satisfactory yields. Characterization of the resulting products was obtained by chromatographic methods. Biological evaluation was performed for both Tc-99m and Re-188 derivatives by in-vitro studies on isolated cells expressing NK1-receptors. In-vivo imaging in mice was carried out using a small-animal YAP(S)PET tomograph.ConclusionNew Tc-99m and Re-188 peptide radiopharmaceuticals with SP have been prepared in high-yield and with high-specific activity. Both Tc-99m and Re-188 peptide radioconjugates exhibit high affinity for NK1 receptors, thus giving further evidence to the empirical rule that structurally related Tc-99m and Re-188 radiopharmaceuticals exhibit identical biological properties.     

Accuracy of radiographers in Fiji in interpreting adult chest X-ray images

IntroductionThe idea of radiographer image interpretation has not been fully explored in Fiji despite the great shortage of radiologists in the country. This is a feasibility study of radiographer image interpretation aimed at assessing the accuracy of radiographers in interpreting adult chest X-ray images at the Colonial War Memorial Hospital (CWMH) in Fiji.MethodsForty PA chest X-ray images were interpreted in terms of correctly commenting on the presence/ absence of pathology, the name of the pathology, and the location of the pathology on the data sheets by the CWMH diagnostic radiographers (n = 14). The radiographers were grouped according to their years of work experience (≤ 5 vs > 5) and the Mann Whitney U test on a two-tailed p-value of 0.05 was used to compare this grouping.ResultsThe data analysis was conducted using the Statistical Package for Social Sciences (SPSS) v.25 and Microsoft Excel. The diagnostic performance of all radiographers in terms of triaging normal and abnormal in the images shows sensitivity ranging from 71.4 to 100%, with specificity ranging from 47.4 to 100%. The mean sensitivity, specificity, and the overall accuracy of radiographers in triaging normal and abnormal on the images were 89.5%, 72.9%, and 81.6%, respectively. The mean accuracy in naming the pathology was 33.6% and the location sensitivity was 45.7%. There was no statistically significant difference in results between the radiographers’ years of experience.ConclusionWithout any formal qualification, training, and practice, the current results suggest that the cohort of radiographers can perform normal/abnormal triage of CXRs within a test setting. With a significant reduction in the radiographers’ accuracy in terms of naming and locating the abnormality, the study results do not support image interpretation by the radiographers at this stage.Implications for practiceThis feasibility study provides baseline information about the accuracy of image interpretation by diagnostic radiographers at CWMH and provides a platform for further research in image interpretation in Fiji.     

ACR CT Accreditation Program and the Lung Cancer Screening Program Designation

The ACR recognizes that low-dose CT for lung cancer screening has the potential to significantly reduce mortality from lung cancer in the appropriate high-risk population. The ACR supports the recommendations of the US Preventive Services Task Force and the National Comprehensive Cancer Network for screening patients. To be effective, lung cancer screening should be performed at sites providing high-quality low-dose CT examinations overseen and interpreted by qualified physicians using a structured reporting and management system. The ACR has developed a set of tools necessary for radiologists to take the lead on the front lines of lung cancer screening. The ACR Lung Cancer Screening Center designation is built upon the ACR CT accreditation program and requires use of Lung-RADS or a similar structured reporting and management system. This designation provides patients and referring providers with the assurance that they will receive high-quality screening with appropriate follow-up care.