Healthcare workers' perspectives on the availability and use of mobile health technologies for disease diagnosis and treatment support in the Ashanti Region of Ghana.

INTRODUCTION: Considering the usefulness of mobile health (mHealth) technologies in healthcare delivery in low- and middle-income countries, including Ghana; there is a need to explore healthcare professionals' perspectives on the availability and use of mHealth for disease screening and treatment of patients' conditions. The study's main aim is to explore healthcare professionals' perspectives regarding the availability and use of mHealth applications for disease screening and management at point-of-care in Ghana's Ashanti Region. MATERIALS AND METHODS: We conducted in-depth interviews with healthcare professionals who use mHealth applications daily between July and September 2020. A purposive sampling strategy was employed to select healthcare professionals who have been using mobile health application tools to support healthcare delivery. The researchers conducted 14 in-depth interviews with healthcare professionals on the availability and use of mHealth applications to support disease diagnosis and treatment of patients' conditions. Data were transcribed, coded, arranged, and analyzed to determine categories and themes. RESULTS: The study results demonstrated that healthcare workers had positive perceptions towards mHealth applications. Healthcare professionals identified significant challenges concerning mHealth applications: the high cost of data; lack of education or limited awareness; poor mobile networks; unstable internet connectivity; erratic power supply; and unavailability of logistics. Healthcare professionals identified the following prerequisite strategies to strengthen the use and scale-up of mHealth applications: stable internet connectivity; creating awareness; supplying logistics; reducing the cost of data; and developing local mobile apps. CONCLUSIONS: The study results revealed the availability of mHealth applications at the individual level for disease screening and treatment support of patients' conditions. The study also showed several significant challenges facing mHealth applications which need to be addressed to guarantee the successful implementation and scaling-up of mHealth activities at all levels of healthcare delivery. Hence, future research should incorporate healthcare professionals' perspectives to completely understand mHealth implementation and scaling-up challenges and measures to inform policy regulations.

A systematic review of academic performance of Children with Disabilities (CWDs) in inclusive education schools in Low and Middle-Income Countries (LMICs).

Globally it is estimated that about 150 million children are living with disabilities. Inclusive education inspires the participation of all students in the learning process in the same classroom. However, it is really difficult to find thorough, credible accounts of disabled children's access to education, enrolment, attendance, and results. This review evaluated academic performance, including access to school, enrolment, attendance, and results of Children with disabilities (CWD) in LMICs. In reporting this systematic review, the researchers followed the recommended Reporting Items for Systematic Review and Meta-Analysis (PRISMA) reporting standards. The authors conducted searches using Science Direct, PubMed, Scopus, and Google Scholar electronic databases. The study's major findings indicate that CWDs in inclusive schools perform poorly academically compared to their non-disabled peers. Consequently, the researchers recommend more primary research to evaluate the academic performance of CWDs and the progress of inclusive education in LMICs.

Telehealth services for global emergencies: implications for COVID-19: a scoping review based on current evidence.

INTRODUCTION: The availability of low-cost computing and digital telecommunication in the 1980s made telehealth practicable. Telehealth has the capacity to improve healthcare access and outcomes for patients while reducing healthcare costs across a wide range of health conditions and situations. OBJECTIVE: This study compares the adoption, advantages, and challenges of telehealth services between high-income (HICs) and low-and-middle-income countries (LMICs) before and during the COVID-19 pandemic. METHODS: Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. The key search terms were: "Telehealth", "Telehealth in HICs", "Telehealth in LMICs", "Telehealth before COVID-19", "Telehealth during COVID-19". We searched exhaustively ProQuest, Scopus, Web of Science, Google Scholar, CINAHL, and EMBASE databases from 2012. Booleans OR/AND were combined with key search terms to increase relevant search results. The literature search and selection process followed the Sample, Phenomena of Interest, Design, Evaluation, and Research (SPIDER) question format. RESULTS: The adoption of telehealth before COVID-19 was generally low in both HICs and LMICs. The impact of COVID-19 accelerated the adoption of telehealth at the facility level but not nationwide in both high-income countries and LMICs. The rapid adoption of telehealth at the facility level in both high-income and LMICs introduced several challenges that are unique to each country and need to be addressed. CONCLUSION: The lack of national policies and regulations is making the adoption of telehealth at the national level challenging in both high and low-middle-income countries. Governments and Stakeholders of healthcare must consider telehealth as a healthcare procedure that should be deployed in clinical working procedures. Primary quantitative and qualitative studies must be conducted to address challenges encountered during the pilot implementation of telehealth services in both high-income countries and LMICs before and during pandemics.

Effects of coronavirus pandemic on expanded program on immunization in weija gbawe municipality (Accra-Ghana).

The introduction of Expanded Program on Immunization (EPI) and the availability of vaccines have contributed to significant reduction in morbidity and mortality rate, particularly among infants and children under five years. The coronavirus pandemic has however interrupted vaccination systems, limiting access and coverage for children. This study assesses the effect of the coronavirus disease outbreak on the EPI activities. The study employed a cross-sectional study design. Purposive and convenience sampling methods were used to sample 510 health workers directly engaged in immunization activities from 15 health care facilities. Coverages for five selected antigens (Diphtheria, Tetanus, Pertussis, Poliomyelitis, Tuberculosis) and Measles in the year 2020 experienced an overall decline ranging from 38.8% for measles rubella vaccine to 53.1% for Penta vaccine. The year 2019 recorded coverages ranging from 69.1% for BCG vaccine to 78.4% for penta vaccine, relatively higher than 2020. EPI services patronization rose up after COVID-19 peaks periods for BCG vaccine 67.7% to 89.2% for penta vaccine. The COVID-19 pandemic disrupted the delivery of EPI services significantly. Healthcare stakeholders can envisage telehealth services in care delivery against pandemic outbreaks. This study contributes to empirical knowledge by recommending vital predictive factors during a pandemic outbreak.

Occupational Health and Safety Measures in Healthcare Settings during COVID-19: Strategies for Protecting Staff, Patients and Visitors.

The COVID-19 (SARS-CoV-2) pandemic has profoundly impacted almost every aspect of healthcare systems worldwide, placing the health and safety of frontline healthcare workers at risk, and it still continues to remain an important public health challenge. Several hospitals have put in place strategies to manage space, staff, and supplies in order to continue to deliver optimum care to patients while at the same time protecting the health and safety of staff and patients. However, the emergence of the second and third waves of the virus with the influx of new cases continue to add an additional level of complexity to the already challenging situation of containing the spread and lowering the rate of transmission, thus pushing healthcare systems to the limit. In this narrative review paper, we describe various strategies including administrative controls, environmental controls, and use of personal protective equipment, implemented by occupational health and safety departments for the protection of healthcare workers, patients, and visitors from SARS-CoV-2 virus infection. The protection and safeguard of the health and safety of healthcare workers and patients through the implementation of effective infection control measures, adequate management of possible outbreaks and minimization of the risk of nosocomial transmission is an important and effective strategy of SARS-CoV-2 pandemic management in any healthcare facility. High quality patient care hinges on ensuring that the care providers are well protected and supported so they can provide the best quality of care to their patients.

Availability and Use of Mobile Health Technology for Disease Diagnosis and Treatment Support by Health Workers in the Ashanti Region of Ghana: A Cross-Sectional Survey.

Mobile health (mHealth) technologies have been identified as promising strategies for improving access to healthcare delivery and patient outcomes. However, the extent of availability and use of mHealth among healthcare professionals in Ghana is not known. The study's main objective was to examine the availability and use of mHealth for disease diagnosis and treatment support by healthcare professionals in the Ashanti Region of Ghana. A cross-sectional survey was carried out among 285 healthcare professionals across 100 primary healthcare clinics in the Ashanti Region with an adopted survey tool. We obtained data on the participants' background, available health infrastructure, healthcare workforce competency, ownership of a mobile wireless device, usefulness of mHealth, ease of use of mHealth, user satisfaction, and behavioural intention to use mHealth. Descriptive statistics were conducted to characterise healthcare professionals' demographics and clinical features. Multivariate logistic regression analysis was performed to explore the influence of the demographic factors on the availability and use of mHealth for disease diagnosis and treatment support. STATA version 15 was used to complete all the statistical analyses. Out of the 285 healthcare professionals, 64.91% indicated that mHealth is available to them, while 35.08% have no access to mHealth. Of the 185 healthcare professionals who have access to mHealth, 98.4% are currently using mHealth to support healthcare delivery. Logistic regression model analysis significantly (p < 0.05) identified that factors such as the availability of mobile wireless devices, phone calls, text messages, and mobile apps are associated with HIV, TB, medication adherence, clinic appointments, and others. There is a significant association between the availability of mobile wireless devices, text messages, phone calls, mobile apps, and their use for disease diagnosis and treatment compliance from the chi-square test analysis. The findings demonstrate a low level of mHealth use for disease diagnosis and treatment support by healthcare professionals at rural clinics. We encourage policymakers to promote the implementation of mHealth in rural clinics.

Systematic Review and Meta-Analysis of the Diagnostic Accuracy of Mobile-Linked Point-of-Care Diagnostics in Sub-Saharan Africa.

Mobile health devices are emerging applications that could help deliver point-of-care (POC) diagnosis, particularly in settings with limited laboratory infrastructure, such as Sub-Saharan Africa (SSA). The advent of Severe acute respiratory syndrome coronavirus 2 has resulted in an increased deployment and use of mHealth-linked POC diagnostics in SSA. We performed a systematic review and meta-analysis to evaluate the accuracy of mobile-linked point-of-care diagnostics in SSA. Our systematic review and meta-analysis were guided by the Preferred Reporting Items requirements for Systematic Reviews and Meta-Analysis. We exhaustively searched PubMed, Science Direct, Google Scholar, MEDLINE, and CINAHL with full text via EBSCOhost databases, from mHealth inception to March 2021. The statistical analyses were conducted using OpenMeta-Analyst software. All 11 included studies were considered for the meta-analysis. The included studies focused on malaria infections, Schistosoma haematobium, Schistosoma mansoni, soil-transmitted helminths, and Trichuris trichiura. The pooled summary of sensitivity and specificity estimates were moderate compared to those of the reference representing the gold standard. The overall pooled estimates of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of mobile-linked POC diagnostic devices were as follows: 0.499 (95% CI: 0.458-0.541), 0.535 (95% CI: 0.401-0.663), 0.952 (95% CI: 0.60-1.324), 1.381 (95% CI: 0.391-4.879), and 0.944 (95% CI: 0.579-1.538), respectively. Evidence shows that the diagnostic accuracy of mobile-linked POC diagnostics in detecting infections in SSA is presently moderate. Future research is recommended to evaluate mHealth devices' diagnostic potential using devices with excellent sensitivities and specificities for diagnosing diseases in this setting.

Interactions of platelets with circulating tumor cells contribute to cancer metastasis.

Recent studies have suggested that platelets have a crucial role in enhancing the survival of circulating tumor cells in the bloodstream and aggravating cancer metastasis. The main function of platelets is to bind to the sites of the damaged vessels to stop bleeding. However, in cancer patients, activated platelets adhere to circulating tumor cells and exacerbate metastatic spreading. Several hypotheses have been proposed about the platelet-cancer cell interactions, but the underlying mechanisms of these interactions are not completely understood yet. In this work, we quantitatively investigated the interactions between circulating tumor cells, red blood cells, platelets, plasma flow and microvessel walls via computational modelling at the cellular scale. Our highly detailed computational model allowed us to understand and quantitatively explain the role of platelets in deformation, adhesion and survival of tumor cells in their active arrest to the endothelium.

Mobile health applications for disease screening and treatment support in low-and middle-income countries: A narrative review.

The advances in mobile technologies and applications are driving the transformation in health services delivery globally. Mobile phone penetration is increasing exponentially in low-and middle-income countries, hence using mobile phones for healthcare services could reach more people in resource-limited settings than the traditional forms of healthcare provision. The review presents recent literature on facilitators and barriers of implementing mHealth for disease screening and treatment support in low-and middle-income countries. We searched for relevant literature from the following electronic databases: MEDLINE; CINAHL with full text via EBSCOhost; Science Direct; PubMed; Google Scholar and Web of Science using the keywords for relevant studies. We searched for published studies from 2015 to August 2020 with no language limitations. A total of 721 articles identified, 125 articles met the inclusion criteria and were included in the qualitative synthesis. The review demonstrates relevant facilitators for the implementation of mHealth, which includes knowledge, attitudes, and perceptions of stakeholders on the use of mHealth and the performance of mHealth for disease diagnosis in low and-middle-income countries. Barriers and challenges hindering the implementation of mHealth applications were also identified. We proposed a framework for improving the implementation of mHealth for disease screening and treatment support in low-and middle-income countries.

Mapping evidence of mobile health technologies for disease diagnosis and treatment support by health workers in sub-Saharan Africa: a scoping review.

BACKGROUND: The rapid growth of mobile technology has given rise to the development of mobile health (mHealth) applications aimed at treating and preventing a wide range of health conditions. However, evidence on the use of mHealth in high disease burdened settings such as sub-Sharan Africa is not clear. Given this, we systematically mapped evidence on mHealth for disease diagnosis and treatment support by health workers in sub-Saharan Africa. METHODS: We conducted a scoping review study guided by the Arksey and O'Malley's framework, Levac et al. recommendations, and Joanna Briggs Institute guidelines. We thoroughly searched the following databases: MEDLINE and CINAHL with full text via EBSCOhost; PubMed; Science Direct and Google Scholar for relevant articles from the inception of mHealth technology to April 2020. Two reviewers independently screened abstracts and full-text articles using the eligibility criteria as reference. This study employed the mixed methods appraisal tool version 2018 to assess the methodological quality of the included studies. RESULTS: Out of the 798 articles identified, only 12 published articles presented evidence on the availability and use of mHealth for disease diagnosis and treatment support by health workers in SSA since 2010. Of the 12 studies, four studies were conducted in Kenya; two in Malawi; two in Nigeria; one in South Africa; one in Zimbabwe; one in Mozambique, and one in Lesotho. Out of the 12 studies, one reported the use of mHealth for diseases diagnosis; three reported the use of mHealth to manage HIV; two on the management of HIV/TB; two on the treatment of malaria; one each on the management of hypertension; cervical cancer; and three were not specific on any disease condition. All the 12 included studies underwent methodological quality appraisal with a scored between 70 and 100%. CONCLUSIONS: The study shows that there is limited research on the availability and use of mHealth by health workers for disease diagnosis and treatment support in sub-Saharan Africa. We, therefore, recommend primary studies focusing on the use of mHealth by health workers for disease diagnosis and treatment support in sub-Saharan Africa.

ASSESSMENT OF OCCUPATIONAL RADIATION DOSES OF MEDICAL RADIATION WORKERS IN TWO COMMUNITY HOSPITALS.

The International Commission on Radiological Protection recommends the adoption of the linear, no-threshold model as a predictive risk model for radiation protection purposes since the relationship between low-dose radiation exposure and cancer risk is unclear. Medical radiation workers are subject to occupational exposures and differences in workload, area of work and types of exposure can lead to variations in exposures between different occupational groups. We investigated the occupational exposures of 572 workers from four departments in two community hospitals and stratified into 22 occupational groups in order to identify groups with the highest radiation exposure. The occupational doses from 2015 to 2019 were analyzed to identify the dose distribution of each occupational group, total number of monitored workers, annual and collective deep (Hp(10)), eye (Hp(3)) and shallow (Hp(0.07)) doses. We further determined the individual and occupational group lifetime doses as well as the probability that monitored workers' lifetime doses will exceed a specified lifetime dose level. The occupational groups with the highest radiation exposures were the nuclear medicine technologists, diagnostic imaging radiologists and diagnostic cardiologists. Although our data suggest that occupational doses reported are low, it is essential that exposure of occupationally exposed personnel are always kept as low as reasonably achievable with an effective radiation protection program.

Availability and use of mHealth for disease diagnosis and treatment support by health workers in sub-Saharan Africa: a scoping review protocol.

INTRODUCTION: Improving healthcare for all is one of the global health priorities, particularly in disease burdened settings such as sub-Saharan Africa (SSA). Considering the high penetration rate of mobile phones in SSA, mobile health (mHealth) could be used to achieve universal health coverage. The proposed study will map evidence on the availability and use of mHealth for disease diagnosis and treatment support by health workers in SSA. METHODS AND ANALYSIS: This review will be guided by Arksey and O'Malley's scoping review framework and Levac et al's recommendations and guidelines from the Joanna Briggs Institute. A scoping review will be conducted to explore what is known about mHealth for disease diagnosis and treatment support by health workers in SSA and to identify areas for future research. In addition to searching the grey literature, the following databases will be explored from PubMed, MEDLINE and CINAHL with full text via EBSCOhost and ScienceDirect databases. A search in Google Scholar will be considered as an additional information source. The literature search will involve published studies from 2000 to 2020 in any language. This review will cover mHealth for disease diagnosis and treatment support by health workers in SSA. The primary investigator will conduct the title screening, and subsequently, two reviewers will independently conduct abstract and full article screening and data extraction. The results of this proposed review will be presented using the Preferred Reporting Items for Systematic Reviews and Meta-analysis: Extension for Scoping Review guidelines. ETHICS AND DISSEMINATION: Ethical approval is not required for the scoping review, which is the first stage in a PhD study in public health on accessing mHealth for disease diagnosis and treatment support by health workers in Ghana. The final review will be submitted for publications to a scientific journal, and our results will be presented at appropriate conferences.

Tuberculosis active case-finding interventions and approaches for prisoners in sub-Saharan Africa: a systematic scoping review.

BACKGROUND: In sub-Saharan Africa (SSA), most prisons are overcrowded with poor ventilation and put prisoners disproportionally at risk of exposure to Mycobacterium tuberculosis (TB) and developing TB infection but are mostly missed due to poor access to healthcare. Active case-finding (ACF) of TB in prisons facilitates early diagnosis and treatment of inmates and prevent the spread. We explored literature and described evidence on TB ACF interventions and approaches for prisoners in SSA prisons. METHODS: Guided by the Arksey and O'Malley framework, we searched PubMed, Google Scholar, SCOPUS, Academic search complete, CINAHL and MEDLINE with full text via EBSCOhost for articles on prisoners and ACF from 2000 to May 2019 with no language restriction. Two investigators independently screened the articles at the abstract and full-text stages in parallel guided by the eligibility criteria as well as performed the methodological quality appraisal of the included studies using the latest mixed-method appraisal tool. We extracted all relevant data, organized them into themes and sub-themes, and presented a narrative summary of the results. RESULTS: Of the 391 eligible articles found, 31 met the inclusion criteria. All 31 articles were published between 2006 and 2019 with the highest six (19.4%) in 2015. We found evidence in 11 countries. That is, Burkina Faso, Cameroon, Coˆte d'Ivoire, the Democratic Republic of the Congo, Ethiopia, Ghana, Malawi, Nigeria, South Africa, Uganda, and Zambia with most 41.9% (13/31) recorded in Ethiopia. These intervention studies were conducted in 134 prisons between 2001 and 2018 using either a single or combination of mass, facility-led, entry, peer educators for routine screening, and exit ACF approaches. The majority (74%) of the studies utilized only a mass screening approach. The most (68%) reported study outcome was smear-positive TB cases only (68%). We found no evidence in 16 SSA countries although they are classified among the three high-burden country lists for TB TB/HIV and Multidrug resistant-TB group. CONCLUSION: Our review highlights a dearth of evidence on TB ACF interventions in most SSA countries prisons. Hence, there is the need to scaling-up ACF interventions in SSA prisons, particularly countries included in the three high-burden country lists for TB, TB/HIV, and MDR-TB.

Mapping evidence on malnutrition screening tools for children under 5 years in sub-Saharan Africa: a scoping review protocol.

BACKGROUND: In sub-Saharan Africa (SSA), malnutrition remains a major public health challenge, particularly among children under 5 years of age. Despite nutritional screening tools being developed and available to detect early malnutrition in under five-year-old children, malnutrition continues to be a health concern. However, the level of evidence on nutritional screening tools for predicting early malnutrition at the community level in a high disease burden setting is unclear. The objective of this scoping review is to systematically map the evidence on malnutrition screening tools for children under 5 years in sub-Saharan Africa (SSA) and to identify knowledge gaps. METHODS: The proposed study will be guided by an improved Arksey and O'Malley's framework, Levac et al. 2010 recommendations, and the 2015 Joanna Briggs Institute guidelines. We will conduct a systematic search of relevant imperial sources of evidence from the following databases: CINAHL with full text, Academic search complete via EBSCOhost, Google Scholar, Science Direct, and PubMed. We will search for grey literature from the following humanitarian and aid organization websites: World Health Organization (WHO), The United Nations International Children's Emergency Fund (UNICEF), and governmental departments. Following the database searches and title screening, eligible sources of evidence will be exported to an EndNote X9 reference library. Thereafter, duplicate articles will be removed in preparation for abstract and full article screenings. Data from the included sources of evidence will be extracted, and the emerging themes will be analyzed. The relationship between the emerging themes and the research questions will be critically examined. The quality of the included sources of evidence will be determined by using the Mixed Method Appraisal Tool (MMAT) version 2018. The search results will be presented in adapted Preferred Reporting Items for Systematic Reviews and Meta-Analysis: Extension for Scoping Reviews chart (PRISMA-ScR). DISCUSSION: We anticipate finding relevant literature on malnutrition screening tools for children under 5 years in SSA. This study is likely to reveal research gaps, which could guide future research on malnutrition screening tools.

A Novel 2D Probability Density Function Integrating the Rectal Motion and Wall Thickness in Prostate IMRT.

BACKGROUND AND PURPOSE: This study investigated the variations of rectal motion and wall thickness in prostate intensity-modulated radiotherapy using a novel 2D probability density function. To evaluate the impact of the position, thickness, and deformation of the rectum on the dose distribution in prostate intensity-modulated radiotherapy plans, probability density functions (pdf) of the deformation of rectal cross-section (DW), rectal dose distribution (RM), and changes in rectal wall thickness (TW) were used in the planning optimization. MATERIALS AND METHODS: The problem of approximating the product of a number of Gaussian mixture distributions arises in the number of parameters describing the specific mean value, standard deviation, and weight in every Gaussian. In this work, a pdf model has been developed which specifies the variability of the average rectal wall thickness. The model is based on the histogram of 587 randomly selected patients with prostate cancer. RESULTS: The average wall thicknesses were determined based on the rectal structure contours drawn on the planning CT image set of the patient. The pdf describing the variability of the rectal wall thickness (pdfTW) is represented as a three-mode Gaussian mixture of specific (µF,σF); (µPF,σPF) and (µE,σE) and individual weights (wF, wPF, and wE) representing full, partially full, and empty rectal states, respectively. CONCLUSION: A 2D Gaussian pdf of rectal motion and rectal thickness (2D pdfM&TW) function, as a product-mixture model of the pdf of the rectal motion (pdfM) and the pdfTW, was developed using published and experimental data, respectively, and presented mathematically. Using correlation values between the functions pdfM and pdfTW, the sensitivity of profiles and projections to the 2D pdfM&TW is numerically demonstrated.

Retrospective study of patients radiation dose during cardiac catheterization procedures.

OBJECTIVE: Cardiac catheterization procedures provide tremendous benefits to modern healthcare and the benefit derived by the patient should far outweigh the radiation risk associated with a properly optimized procedure. With increasing utilization of such procedures, there is growing concern regarding the magnitude and variations of dose to patients associated with procedure complexity and techniques parameters. Therefore, this study investigated radiation dose to patients from six cardiac catheterization procedures at our facility and suggest possible initial dose values for benchmark for patient radiation dose from these procedures. This initial benchmark data will be used for clinical radiation dose management which is essential for assessing the impact of any quality improvement initiatives in the cardiac catheterization laboratory. METHODS: We retrospectively analyzed the dose parameters of 1000 patients who underwent various cardiac catheterization procedures: left heart catheterization (LH), percutaneous coronary intervention (PCI), complex PCI, LH with complex PCI, LH with PCI and cardiac resynchronization therapy (CRT) pacemaker in our cardiac catheterization laboratories. Patient's clinical radiation dose data [kerma-area-product (KAP) and air-kerma at the interventional reference point (Ka,r)] and technique parameters (fluoroscopy time, tube potential, current, pulse width and number of cine images) along with demographic information (age, height and weight) were collected from the hospital's RIS (Synapse), Sensis/Syngo Dynamics and Siemens Sensis Stats Manager electronic database. Statistical analysis was performed with the IBM SPSS Modeler v. 18.1 software. RESULTS: The overall patient median age was 67.0 (range: 26.0-97.0) years and the median body mass index (BMI) was 28.8 (range: 15.9-61.7) kg/m2 . The median KAP for the LH, PCI, LH with complex PCI, complex PCI, LH with PCI and CRT-pacemaker procedures are 44.4 (4.1-203.2), 80.2 (18.9-208.5), 83.7 (48.0-246.1), 113.8 (60.9-284.5), 91.7 (6.0-426.0) and 51.1 (7.0-175.9) Gy-cm2 . The median Ka,r for the LH, PCI, LH with complex PCI, complex PCI, LH with PCI and CRT-pacemaker procedures are 701.0 (35.3-3794.0), 1384.7 (291.7-4021.8), 1607.0 (883.5-4448.3), 2260.2 (867.4-5311.9), 1589.3 (100.2-7237.4) and 463.8 (67.7-1695.9) mGy respectively. CONCLUSION: We have analyzed patient radiation doses from six commonly used procedures in our cardiac catheterization laboratories and suggested possible initial values for benchmark from these procedures for the fluoroscopy time, KAP and air-kerma at the interventional reference point based on our current practices. Our data compare well with published values reported in the literature by investigators who have also studied patient doses and established benchmark dose levels for their facilities. Procedure-specific benchmark dose data for various groups of patients can provide the motivation for monitoring practices to promote improvements in patient radiation dose optimization in the cardiac catheterization laboratories. ADVANCES IN KNOWLEDGE: We have investigated local patients' radiation doses and established benchmark radiation data which are essential for assessing the impact of any quality improvement initiatives for radiation dose optimization.

Biodistribution and Physiologically-Based Pharmacokinetic Modeling of Gold Nanoparticles in Mice with Interspecies Extrapolation.

Gold nanoparticles (AuNPs) are a focus of growing medical research applications due to their unique chemical, electrical and optical properties. Because of uncertain toxicity, "green" synthesis methods are emerging, using plant extracts to improve biological and environmental compatibility. Here we explore the biodistribution of green AuNPs in mice and prepare a physiologically-based pharmacokinetic (PBPK) model to guide interspecies extrapolation. Monodisperse AuNPs were synthesized and capped with epigallocatechin gallate (EGCG) and curcumin. 64 CD-1 mice received the AuNPs by intraperitoneal injection. To assess biodistribution, groups of six mice were sacrificed at 1, 7, 14, 28 and 56 days, and their organs were analyzed for gold content using inductively coupled plasma mass spectrometry (ICP-MS). A physiologically-based pharmacokinetic (PBPK) model was developed to describe the biodistribution data in mice. To assess the potential for interspecies extrapolation, organism-specific parameters in the model were adapted to represent rats, and the rat PBPK model was subsequently evaluated with PK data for citrate-capped AuNPs from literature. The liver and spleen displayed strong uptake, and the PBPK model suggested that extravasation and phagocytosis were key drivers. Organ predictions following interspecies extrapolation were successful for rats receiving citrate-capped AuNPs. This work lays the foundation for the pre-clinical extrapolation of the pharmacokinetics of AuNPs from mice to larger species.

Dosimetric evaluation of whole-breast radiation therapy: clinical experience.

Radiation therapy of the intact breast is the standard therapy for preventing local recurrence of early-stage breast cancer following breast conservation surgery. To improve patient standard of care, there is a need to define a consistent and transparent treatment path for all patients that reduces significance variations in the acceptability of treatment plans. There is lack of consistency among institutions or individuals about what is considered an acceptable treatment plan: target coverage vis-à-vis dose to organs at risk (OAR). Clinical trials usually resolve these issues, as the criteria for an acceptable plan within the trial (target coverage and doses to OAR) are well defined. We developed an institutional criterion for accepting breast treatment plans in 2006 after analyzing treatment data of approximately 200 patients. The purpose of this article is to report on the dosimetric review of 623 patients treated in the last 18 months to evaluate the effectiveness of the previously developed plan acceptability criteria and any possible changes necessary to further improve patient care. The mean patient age is 61.6 years (range: 25.2 to 93.0 years). The mean breast separation for all the patients is 21.0cm (range: 12.4 to 34.9cm), and the mean planning target volume (PTV_eval) (breast volume for evaluation) is 884.0cm(3) (range: 73.6 to 3684.6cm(3)). Overall, 314 (50.4%) patients had the disease in the left breast and 309 (49.6%) had it in the right breast. A total of 147 (23.6%) patients were treated using the deep inspiration breath-hold (DIBH) technique. The mean normalized PTV_eval receiving at least 92% (V92% PD) and 95% (V95% PD) of the prescribed dose (PD) are more than 99% and 97%, respectively, for all patients. The mean normalized PTV_eval receiving at least 105% (V105% PD) of the PD is less than 1% for all groups. The mean homogeneity index (HI), uniformity index (UI), and conformity index (CI) for the PTV_eval are 0.09 (range: 0.05 to 0.15), 1.07 (range: 0.46 to 1.11), and 0.98 (range: 0.92 to 1.0), respectively. Our data confirm the significant advantage of using DIBH to reduce heart dose when compared with the free-breathing technique. The p values analyses of the results for the V5Gy, V10Gy, V15Gy, V20Gy, and V30Gy for the heart comparing DIBH and free-breathing techniques are well less than 0.05 (i.e., p < 0.05). However, similar analyses for the lung give values greater than 0.05 (i.e., p > 0.05), indicating that there is no significant difference in lung dose comparing the 2 treatment techniques.

Bismuth sulfide nanoflowers for detection of X-rays in the mammographic energy range.

The increased use of diagnostic x-rays, especially in the field of medical radiology, has necessitated a significant demand for high resolution, real-time radiation detectors. In this regard, the photoresponse of bismuth sulfide (Bi2S3), an n-type semiconducting metal chalcogenide, to low energy x-rays has been investigated in this study. In recent years, several types of nanomaterials of Bi2S3 have been widely studied for optoelectronic and thermoelectric applications. However, photoresponse of Bi2S3 nanomaterials for dosimetric applications has not yet been reported. The photosensitivity of Bi2S3 with nanoscale "flower-like" structures was characterized under x-ray tube-potentials typically used in mammographic procedures. Both dark current and photocurrent were measured under varying x-ray doses, field sizes, and bias voltages for each of the tube potentials - 20, 23, 26 and 30 kV. Results show that the Bi2S3 nanoflowers instantaneously responded to even minor changes in the dose delivered. The photoresponse was found to be relatively high (few nA) at bias voltage as low as +1 V, and fairly repeatable for both short and long exposures to mammographic x-rays with minimal or no loss in sensitivity. The overall dose-sensitivity of the Bi2S3 nanoflowers was found to be similar to that of a micro-ionization chamber.

Margin selection to compensate for loss of target dose coverage due to target motion during external-beam radiation therapy of the lung.

The aim of this study is to provide guidelines for the selection of external-beam radiation therapy target margins to compensate for target motion in the lung during treatment planning. A convolution model was employed to predict the effect of target motion on the delivered dose distribution. The accuracy of the model was confirmed with radiochromic film measurements in both static and dynamic phantom modes. 502 unique patient breathing traces were recorded and used to simulate the effect of target motion on a dose distribution. A 1D probability density function (PDF) representing the position of the target throughout the breathing cycle was generated from each breathing trace obtained during 4D CT. Changes in the target D95 (the minimum dose received by 95% of the treatment target) due to target motion were analyzed and shown to correlate with the standard deviation of the PDF. Furthermore, the amount of target D95 recovered per millimeter of increased field width was also shown to correlate with the standard deviation of the PDF. The sensitivity of changes in dose coverage with respect to target size was also determined. Margin selection recommendations that can be used to compensate for loss of target D95 were generated based on the simulation results. These results are discussed in the context of clinical plans. We conclude that, for PDF standard deviations less than 0.4 cm with target sizes greater than 5 cm, little or no additional margins are required. Targets which are smaller than 5 cm with PDF standard deviations larger than 0.4 cm are most susceptible to loss of coverage. The largest additional required margin in this study was determined to be 8 mm.