Influence of Accuracy and Precision of Measurements of Long Bone Tumors in Imaging Studies-A Retrospective Study in Musculoskeletal Oncology.

The aim of this study is to evaluate the level of accuracy and precision of bone scan (BS), MRI, and digital radiography (DR) to measure long bone tumors to design custom-made prosthesis (CMP)/modular prosthesis (MP) in limb salvage surgery (LSS) with the help of phantom and patient's study. There are two separate groups: one is the phantom study and another one is the patient's study. The phantom study is done with the Jaszack Phantom for the Gamma camera and the indigenous phantom for the MRI and DR. Three independent imaging professionals (nuclear medicine physicians and radiologists) measured the distance between standardized, preselected points on the Jaszack phantom in the Gamma Camera (GC) and indigenous phantom on the coronal and sagittal view of the MRI scan and in digital radiography. The measured values were compared with the known values for phantom measurement. A total of 36 patients, which include 24 males and 12 females, 3 independent imaging professionals measured the patient's long bone in a bone scan, MRI and DR and compared it with histopathological specimen measurement after limb salvage surgery (LSS). Descriptive statistics using appropriate measures of central tendency and dispersion were employed to describe the data. Karl-Pearson correlation coefficient was used to establish the association between continuous covariates. Paired t-test was utilized to test the differences in paired values for statistical significance. A near-perfect positive correlation was evident between all three pairs of bone scan, MRI scan, and digital radiography values, and a positive agreement within 1 mm of the bone scan, MRI scan, and DR values of all three pairs was around 95%. For the phantom study, we conclude that Gamma camera and MRI measurements are equal in physical measurements (MCF-1). DR measurements were found to be near equal physical measurements and multiplication correction factor (MCF)-0.9104 and three observer's measurements values were also near normal. For the patient's study, we conclude that the bone scan, MRI, and DR measurements of 3 independent imaging professionals are near normal, and it was confirmed with pathological specimen after LSS, to confirm reliability, repeatability, reproducibility, and accuracy of the tumor length to do custom-made prosthesis or modular prosthesis for the patients who are affected by osteosarcoma and Ewing's sarcoma.

Resilience as a communal concept: Understanding adolescent resilience in the context of the Syrian refugee crisis in Bar Elias, Lebanon.

BACKGROUND: The conflict in Syria has led to the displacement of 1.5 million refugees into the neighboring country of Lebanon, with a majority that have yet to return to their homeland. Syrian adolescents in the town of Bar Elias in the Bekaa Valley, Lebanon have lived and grown in the face of resource-limited environments, restricted movement, and a longing for return. Resilience is manifested in the adaptation to such circumstances through close supportive relationships, social engagement, employment, and religion. There is a communal aspect to resilience that is important to the adolescent refugee experience and to the efforts supporting these communities. METHODS: Fifteen one-to-one interviews and two focus groups, with a total of eighteen Syrian adolescents, were analyzed using an inductive thematic analysis informed by grounded theory principles. Participants were recruited through partnering non-governmental organizations (NGOs) in the area, and ethical approval was granted through UCL and the American University in Beirut (AUB). RESULTS: Syrian adolescents highlighted supportive relationships, communal activities and spaces, memories of home, employment, and shared environments as integral elements to their personal adaptation. Methods of resilience involved social cohesion and establishing stability for one's family and close community. Adaptation to the present is intertwined with facing the consequences of displacement in this new context and maintaining aspirations for a bright future. Engaging with the environments they share and help create is an important facet of resilience and occurs through group gatherings , hobbies, and online communication. Additionally, inner strength can be derived from religious activities and empowers individual processing. CONCLUSION: This study illuminates the elements and mechanisms embodied in these adolescents' communities and relationships that allow for adaptation to life in Bar Elias. These factors strengthen their approach to overcome social barriers and practice resilience. These communal aspects of the adolescents' lives also connect to their memories of home, current environment, and future aspirations.

Patterns of domestic exposure to carbon monoxide and particulate matter in households using biomass fuel in Janakpur, Nepal.

Household Air Pollution (HAP) from biomass cooking fuels is a major cause of morbidity and mortality in low-income settings worldwide. In Nepal the use of open stoves with solid biomass fuels is the primary method of domestic cooking. To assess patterns of domestic air pollution we performed continuous measurement of carbon monoxide (CO) and particulate Matter (PM2.5) in 12 biomass fuel households in Janakpur, Nepal. We measured kitchen PM2.5 and CO concentrations at one-minute intervals for an approximately 48-h period using the TSI DustTrak II 8530/SidePak AM510 (TSI Inc, St. Paul MN, USA) or EL-USB-CO data logger (Lascar Electronics, Erie PA, USA) respectively. We also obtained information regarding fuel, stove and kitchen characteristics and cooking activity patterns. Household cooking was performed in two daily sessions (median total duration 4 h) with diurnal variability in pollutant concentrations reflecting morning and evening cooking sessions and peak concentrations associated with fire-lighting. We observed a strong linear relationship between PM2.5 measurements obtained by co-located photometric and gravimetric monitoring devices, providing local calibration factors of 4.9 (DustTrak) and 2.7 (SidePak). Overall 48-h average CO and PM2.5 concentrations were 5.4 (SD 4.3) ppm (12 households) and 417.6 (SD 686.4) µg/m3 (8 households), respectively, with higher average concentrations associated with cooking and heating activities. Overall average PM2.5 concentrations and peak 1-h CO concentrations exceeded WHO Indoor Air Quality Guidelines. Average hourly PM2.5 and CO concentrations were moderately correlated (r = 0.52), suggesting that CO has limited utility as a proxy measure for PM2.5 exposure assessment in this setting. Domestic indoor air quality levels associated with biomass fuel combustion in this region exceed WHO Indoor Air Quality standards and are in the hazardous range for human health.

Association between Birth Interval and Cardiovascular Outcomes at 30 Years of Age: A Prospective Cohort Study from Brazil.

BACKGROUND: Birth interval is an important and potentially modifiable factor that is associated with child health. Whether an association exists with longer-term outcomes in adults is less well known. METHODS: Using the 1982 Pelotas (Brazil) Birth Cohort Study, the association of birth interval with markers of cardiovascular health at 30 years of age was examined. Multivariable linear regression was used with birth interval as a continuous variable and categorical variable, and effect modification by gender was explored. RESULTS: Birth interval and cardiovascular data were present for 2,239 individuals. With birth interval as a continuous variable, no association was found but stratification by gender tended to show stronger associations for girls. When compared to birth intervals of <18 months, as binary variable, longer intervals were associated with increases in height (1.6 cm; 95% CI: 0.5, 2.8) and lean mass (1.7 kg; 95% CI: 0.2, 3.2). No difference was seen with other cardiovascular outcomes. CONCLUSIONS: An association was generally not found between birth interval and cardiovascular outcomes at 30 years of age, though some evidence existed for differences between males and females and for an association with height and lean mass for birth intervals of 18 months and longer.

Can positron emission tomography be more than a diagnostic tool? A survey on clinical practice among radiation oncologists in India.

AIM: The purpose of the survey was to understand the role of positron emission tomography (PET) in clinical radiotherapy practice among the radiation oncologists' in India. SETTINGS AND DESIGN: An online questionnaire was developed to survey the oncologists on their use of PET, viewing protocols, contouring techniques practiced, the barriers on the use of PET and the need for training in use of PET in radiotherapy. The questionnaire was sent to about 500 oncologists and 76 completed responses were received. RESULTS: The survey shows that radiation oncologists use PET largely to assess treatment response and staging but limitedly use it for radiotherapy treatment planning. Only manual contouring and fixed threshold based delineation techniques (e.g. 40% maximum standard uptake value [SUV max ] or SUV 2.5) are used. Cost is the major barrier in the wider use of PET, followed by limited availability of FDG radionuclide tracer. Limited or no training was available for the use of PET. CONCLUSIONS: Our survey revealed the vast difference between literature suggestions and actual clinical practice on the use of PET in radiotherapy. Additional training and standardization of protocols for use of PET in radiotherapy is essential for fully utilizing the capability of PET.

Biomass fuel use and the exposure of children to particulate air pollution in southern Nepal.

The exposure of children to air pollution in low resource settings is believed to be high because of the common use of biomass fuels for cooking. We used microenvironment sampling to estimate the respirable fraction of air pollution (particles with median diameter less than 4 µm) to which 7-9 year old children in southern Nepal were exposed. Sampling was conducted for a total 2649 h in 55 households, 8 schools and 8 outdoor locations of rural Dhanusha. We conducted gravimetric and photometric sampling in a subsample of the children in our study in the locations in which they usually resided (bedroom/living room, kitchen, veranda, in school and outdoors), repeated three times over one year. Using time activity information, a 24-hour time weighted average was modeled for all the children in the study. Approximately two-thirds of homes used biomass fuels, with the remainder mostly using gas. The exposure of children to air pollution was very high. The 24-hour time weighted average over the whole year was 168 µg/m(3). The non-kitchen related samples tended to show approximately double the concentration in winter than spring/autumn, and four times that of the monsoon season. There was no difference between the exposure of boys and girls. Air pollution in rural households was much higher than the World Health Organization and the National Ambient Air Quality Standards for Nepal recommendations for particulate exposure.

Tracking sickness through social networks - the practical use of social network mapping in supporting the management of an E. coli O157 outbreak in a primary school in London.

This paper describes the practical use of social network diagrams in the management of an outbreak of Escherichia coli O157 (VTEC) in a primary school in London. The diagrams were created during the outbreak to establish the extent and nature of person-to-person transmission in the cases and their contacts. The diagrams supported a tailored public health action, and hence aided in the control of the outbreak. We conclude that for selected infectious diseases, social network diagrams can provide a valuable tool in the management of an outbreak.

Validation of image registration and fusion of MV CBCT and planning CT for radiotherapy treatment planning.

In areas like adaptive therapy, multi-phase radiotherapy, and single fraction palliative treatment or in the treatment of patients with metal implants where megavoltage(MV) CT could be considered as a treatment planning modality, the reduced contrast in the MV CT images could lead to limited accuracy in localization of the structures. This would affect the precision of the treatment. In this study, as an extension our previous work on bespoke MV cone beam CT (MV CBCT), we propose to register the MV CBCT with kilovoltage (kV) CT for treatment planning. The MV CBCT images registered with kV CT would be effective for treatment planning as it would account for the inadequate soft tissue information in the MV CBCT and would allow comparison of changes in patient dimensions and assist in localization of the structures. The intensity based registration algorithm of the BrainSCAN therapy planning software was used for image registration of the MV CBCT and kV CT images. The accuracy of the registration was validated using qualitative and quantitative measures. The effect of image quality on the level of agreement between the contouring done on both the MV CBCT and kV CT was assessed by comparing the volumes of six structures delineated. To assess the level of agreement between the plans after the registration, two independent plans were generated on the MV CBCT and the planning CT using the posterior fossa of the skull as the target. The dose volume histograms and conformity indices of the plans were compared. The results of this study show that treatment planning with MV CBCT images would be effective, using additional anatomical structure information derived from registering the MV CBCT image with a standard kVCT.

The adaptation of megavoltage cone beam CT for use in standard radiotherapy treatment planning.

Potential areas where megavoltage computed tomography (MVCT) could be used are second- and third-phase treatment planning in 3D conformal radiotherapy and IMRT, adaptive radiation therapy, single fraction palliative treatment and for the treatment of patients with metal prostheses. A feasibility study was done on using MV cone beam CT (CBCT) images generated by proprietary 3D reconstruction software based on the FDK algorithm for megavoltage treatment planning. The reconstructed images were converted to a DICOM file set. The pixel values of megavoltage cone beam computed tomography (MV CBCT) were rescaled to those of kV CT for use with a treatment planning system. A calibration phantom was designed and developed for verification of geometric accuracy and CT number calibration. The distance measured between two marker points on the CBCT image and the physical dimension on the phantom were in good agreement. Point dose verification for a 10 cm x 10 cm beam at a gantry angle of 0 degrees and SAD of 100 cm were performed for a 6 MV beam for both kV and MV CBCT images. The point doses were found to vary between +/-6.1% of the dose calculated from the kV CT image. The isodose curves for 6 MV for both kV CT and MV CBCT images were within 2% and 3 mm distance-to-agreement. A plan with three beams was performed on MV CBCT, simulating a treatment plan for cancer of the pituitary. The distribution obtained was compared with those corresponding to that obtained using the kV CT. This study has shown that treatment planning with MV cone beam CT images is feasible.