Health and Medical Physics Commons^™

Landmark-Based Auto-Contouring Of Clinical Target Volumes For Radiotherapy Of Nasopharyngeal Cancer, Carlos Sjogreen, Tucker J Netherton, Anna Lee, Moaaz Soliman, Skylar S Gay, Callistus Nguyen, Raymond Mumme, Ivan Vazquez, Dong Joo Rhee, Carlos E Cardenas, Mary K Martel, Beth M Beadle, Laurence Edward Court

Faculty, Staff and Student Publications

Background: The delineation of clinical target volumes (CTVs) for radiotherapy for nasopharyngeal cancer is complex and varies based on the location and extent of disease.

Purpose: The current study aimed to develop an auto-contouring solution following one protocol guidelines (NRG-HN001) that can be adjusted to meet other guidelines, such as RTOG-0225 and the 2018 International guidelines.

Methods: The study used 2-channel 3-dimensional U-Net and nnU-Net framework to auto-contour 27 normal structures in the head and neck (H&N) region that are used to define CTVs in the protocol. To define the CTV-Expansion (CTV1 and CTV2) and CTV-Overall (the outer envelope of …

Outpatient Fall Prevention In Ambulatory Adults 65 Years Old And Over, Dorothy L. Osborne-White

Doctor of Nursing Practice (DNP) Scholarly Projects - Archive

Background: In the United States (U.S.), falls are the leading cause of injury among adults 65 and over, resulting in 36 million falls yearly (Moreland et al., 2020). According to the Centers for Disease Control and Prevention (CDC, 2023), one in four older adults experiences a fall each year. Falls are the world's second most prominent cause of accidental deaths (World Health Organization [WHO], 2021). Falls are the leading cause of both fatal and non-fatal injuries among older adults (Moreland et al., 2020).

Methods: A quality improvement project that included a fall bundle was implemented in a primary clinic. A …

Identifying The Optimal Deep Learning Architecture And Parameters For Automatic Beam Aperture Definition In 3d Radiotherapy, Skylar S Gay, Kelly D Kisling, Brian M Anderson, Lifei Zhang, Dong Joo Rhee, Callistus Nguyen, Tucker Netherton, Jinzhong Yang, Kristy Brock, Anuja Jhingran, Hannah Simonds, Ann Klopp, Beth M Beadle, Laurence E Court, Carlos E Cardenas

Faculty, Staff and Student Publications

PURPOSE: Two-dimensional radiotherapy is often used to treat cervical cancer in low- and middle-income countries, but treatment planning can be challenging and time-consuming. Neural networks offer the potential to greatly decrease planning time through automation, but the impact of the wide range of hyperparameters to be set during training on model accuracy has not been exhaustively investigated. In the current study, we evaluated the effect of several convolutional neural network architectures and hyperparameters on 2D radiotherapy treatment field delineation.

METHODS: Six commonly used deep learning architectures were trained to delineate four-field box apertures on digitally reconstructed radiographs for cervical cancer …

Comprehensive Evaluation And New Recommendations In The Use Of Gafchromic Ebt3 Film, Kevin Liu, Patrik Gonçalves Jorge, Ramesh Tailor, Raphaël Moeckli, Emil Schüler

Faculty, Staff and Student Publications

BACKGROUND: Gafchromic film's unique properties of tissue-equivalence, dose-rate independence, and high spatial resolution make it an attractive choice for many dosimetric applications. However, complicated calibration processes and film handling limits its routine use.

PURPOSE: We evaluated the performance of Gafchromic EBT3 film after irradiation under a variety of measurement conditions to identify aspects of film handling and analysis for simplified but robust film dosimetry.

METHODS: The short- (from 5 min to 100 h) and long-term (months) film response was evaluated for clinically relevant doses of up to 50 Gy for accuracy in dose determination and relative dose distributions. The dependence …

View-Sharing For 4d Magnetic Resonance Imaging With Randomized Projection-Encoding Enables Improvements Of Respiratory Motion Imaging For Treatment Planning In Abdominothoracic Radiotherapy, Ergys Subashi, Li Feng, Yilin Liu, Scott Robertson, Paul Segars, Bastiaan Driehuys, Christopher R Kelsey, Fang-Fang Yin, Ricardo Otazo, Jing Cai

Faculty, Staff and Student Publications

BACKGROUND AND PURPOSE: The accuracy and precision of radiation therapy are dependent on the characterization of organ-at-risk and target motion. This work aims to demonstrate a 4D magnetic resonance imaging (MRI) method for improving spatial and temporal resolution in respiratory motion imaging for treatment planning in abdominothoracic radiotherapy.

MATERIALS AND METHODS: The spatial and temporal resolution of phase-resolved respiratory imaging is improved by considering a novel sampling function based on quasi-random projection-encoding and peripheral k-space view-sharing. The respiratory signal is determined directly from k-space, obviating the need for an external surrogate marker. The average breathing curve is used to optimize …

Infrastructure Development For Personalized Risk Prediction To Reduce Cardiovascular Disease In Childhood Cancer Survivors, Suman Shrestha

Dissertations and Theses (Open Access)

Although childhood cancer survivors have lengthy life expectancies, they run the risk of experiencing long-term health issues as a result of their treatment. The most frequent non-cancerous cause of morbidity and mortality for these survivors is cardiac disease. Radiation therapy (RT) has been linked in numerous cohort studies to a higher chance of developing a late cardiac disease in these survivors, and this risk rises with higher mean heart doses and increased RT exposure to larger cardiac volumes. Since, the heart is a heterogeneous organ made up of several distinct substructures, RT dose received by the entire heart does not …

Knowledge-Based Planning For The Radiation Therapy Treatment Plan Quality Assurance For Patients With Head And Neck Cancer, Wenhua Cao, Mary Gronberg, Adenike Olanrewaju, Thomas Whitaker, Karen Hoffman, Carlos Cardenas, Adam Garden, Heath Skinner, Beth Beadle, Laurence Court

Faculty, Staff and Student Publications

This study aimed to investigate the feasibility of using a knowledge-based planning technique to detect poor quality VMAT plans for patients with head and neck cancer. We created two dose-volume histogram (DVH) prediction models using a commercial knowledge-based planning system (RapidPlan, Varian Medical Systems, Palo Alto, CA) from plans generated by manual planning (MP) and automated planning (AP) approaches. DVHs were predicted for evaluation cohort 1 (EC1) of 25 patients and compared with achieved DVHs of MP and AP plans to evaluate prediction accuracy. Additionally, we predicted DVHs for evaluation cohort 2 (EC2) of 25 patients for which we intentionally …

Living Environment Considerations On Obesity Prevention Behaviors And Self-Efficacy Among Chinese Americans, Doreen Liou, Jessica A. Karasik

Department of Nutrition and Food Studies Scholarship and Creative Works

The aim of this study is to ascertain if the living environment (type of residential neighborhood and number of household members) will elucidate differences in obesity risk reduction behaviors and self-efficacy in Chinese Americans. A cross-sectional survey design was used to recruit participants from Los Angeles County and New York City metropolitan areas. A total of 650 adults were recruited from diverse socioeconomic backgrounds. Descriptive statistics were measured for 19 behaviors reflecting food intake and portion size control and items measuring self-efficacy and attitudes. T-tests were applied for the two categories of living environment. The mean age of the sample …

Migration As A Determinant Of Childhood Obesity In The United States And Latin America, Mireya Vilar-Compte, Arturo V. Bustamante, Nancy López-Olmedo, Pablo Gaitán-Rossi, Jaqueline Torres, Karen E. Peterson, Graciela Teruel, Rafael Pérez-Escamilla

Department of Public Health Scholarship and Creative Works

International migration has economic and health implications. The acculturation process to the host country may be linked to childhood obesity. We use the Community Energy Balance (CEB) framework to analyze the relationship between migration and childhood obesity in Mexican households with international migrants. Using longitudinal data from the Mexican Family Life Survey (MxFLS), we examine how migrant networks affect childhood obesity in origin communities. We also review binational health programs that could be effective at tackling childhood obesity in migrant households from Mexico. Children embedded in migrant networks are at greater risk of developing overweight or obesity, suggesting a significant …

Implementation Of Childhood Obesity Prevention And Control Policies In The United States And Latin America: Lessons For Cross-Border Research And Practice, Rafael Perez-Escamilla, Mireya Vilar-Compte, Elizabeth Rhodes, Olga L. Sarmiento, Camila Corvalan, Rachel Sturke, Susan Vorkoper

Department of Public Health Scholarship and Creative Works

Progress has been made in the development and widespread implementation of effective interventions to address childhood obesity, yet important challenges remain. To understand how the United States and Latin American countries achieved success in implementing obesity policies and programs (PAPs) and identify improvement opportunities using implementation science principles. We identified three comparative case studies: (1) front-of-food package labeling (Mexico and Chile); (2) Open Streets/play streets (Colombia and the United States); and (3) the Baby-Friendly Hospital Initiative (Brazil and the United States). Information from multiple sources (e.g., scientific and gray literature and key informant interviews) was synthesized to describe barriers, facilitators, …

Costing Of Actions To Safeguard Vulnerable Mexican Households With Young Children From The Consequences Of Covid-19 Social Distancing Measures, Mireya Vilar-Compte, Víctor Pérez, Graciela Teruel, Aranzazu Alonso, Rafael Pérez-Escamilla

Department of Public Health Scholarship and Creative Works

COVID-19 has imposed unprecedented challenges to society. As the pandemic evolves, the social distancing measures that have been globally enforced, while essential, are having undesirable socioeconomic side effects particularly among vulnerable populations. In Mexico, families who depend upon informal employment face increased threats to their wellbeing, and households who in addition have young children may face long-term consequences. The Mexican government has not yet taken actions, but a coalition of non-governmental organizations is advocating in partnership with academic institutions for social protection actions such as a cash transfer and basic services subsidies for families with young children, subsisting from the …

¡Sí, Yo Puedo Vivir Sano Con Diabetes! A Self-Management Randomized Controlled Pilot Trial For Low-Income Adults With Type 2 Diabetes In Mexico City, Robin Whittemore, Mireya Vilar-Compte, Selene De La Cerda, Roberta Delvy, Sangchoon Jeon, Soraya Burrola-Méndez, Mariana Pardo-Carrillo, Annel Lozano-Marrufo, Rafael Pérez-Escamilla

Department of Public Health Scholarship and Creative Works

Background: Type 2 diabetes (T2D) is a worldwide epidemic and a leading cause of death in Mexico, with a prevalence of 15.9%, and >70% of diagnosed adults have poor glycemic control [glycated hemoglobin (HbA1c) >7.5%]. We developed a diabetes self-management education program contextualized to the study population, including dietary preferences, health literacy, and health system.

Objectives: We aimed to evaluate the efficacy of a self-management + text message program (¡Sí, Yo Puedo Vivir Sano con Diabetes!) on primary (HbA1c), and secondary behavioral (self-management), clinical, and psychosocial outcomes in adults with T2D in Mexico City.

Methods: Participants were recruited at public …

Development Of A Diabetes Self-Management + Mhealth Program: Tailoring The Intervention For A Pilot Study In A Low-Income Setting In Mexico, Robin Whittemore, Mireya Vilar-Compte, Soraya Burrola-Méndez, Annel Lozano-Marrufo, Roberta Delvy, Mariana Pardo-Carrillo, Selene De La Cerda, Ninfa Pena-Purcell, Rafael Pérez-Escamilla

Department of Public Health Scholarship and Creative Works

Background: Type 2 diabetes (T2D) is a public health pandemic disproportionately affecting low- and middle-income countries. The purpose of this formative research was to adapt evidence-based diabetes self-management education programs to the context of Seguro Popular clinics in Mexico. A theory-based mHealth (pictorial text messaging) component was developed.

Method: Our formative research and development of the program protocol consisted of six phases: (1) interviews and focus groups with stakeholders on the challenges to T2D management, curriculum content needs, and the use of mHealth as a supplement to a DSME program; (2) review of the theoretical underpinning, curriculum, and interactive strategies …

Quantitative Study Of The Antimicrobial Effects Of Silver On The Motility Of Escherichia Coli, Benjamin Russell

Graduate Theses and Dissertations

In recent decades, the number of antibiotic-resistant bacterial infections has grown to become a serious global threat. This rise can be attributed to the widespread misuse of antibiotics and the lack of newly developed drugs to fight resistant organisms. Novel bactericidal substances have, therefore, garnered significant research interest. Silver, due to its powerful antimicrobial effects, is one such substance. Silver is typically most effective in cationic form; however, advancements in nanotechnology have paved the way for the controlled fabrication of nano-silver. Silver nanoparticles have been shown to have increased antibacterial potency for a variety of reasons, including the release of …

Challenges To Diabetes Self-Management For Adults With Type 2 Diabetes In Low-Resource Settings In Mexico City: A Qualitative Descriptive Study, Robin Whittemore, Mireya Vilar-Compte, Selene De La Cerda, Denise Marron, Rosabelle Conover, Roberta Delvy, Annel Lozano-Marrufo, Rafael Pérez-Escamilla

Department of Public Health Scholarship and Creative Works

Background: The prevalence of type 2 diabetes (T2D) in Mexico is one of the highest in the world, with high morbidity and mortality, and difficulty meeting glycemic targets. The purpose of this study was to identify the challenges for T2D self-management as perceived by both adults with T2D and health care providers in primary health clinics from Seguro Popular in Mexico City.

Methods: This was a qualitative descriptive study conducted in three Seguro Popular primary care clinics in Mexico City using convenience sampling. Semi-structured interviews were conducted with participants and data were analyzed using a content analysis approach.

Results: The …

Short Relative Leg Length Is Associated With Overweight And Obesity In Mexican Immigrant Women, Mireya Vilar-Compte, James Macinko, Beth C. Weitzman, Carlos M. Avendaño-Villela

Department of Public Health Scholarship and Creative Works

Background: Prior research suggests that undernutrition and enteric infections predispose children to stunted growth. Undernutrition and infections have been associated with limited access to healthy diets, lack of sanitation, and access barriers to healthcare - all associated with human rights. Stunting has also been documented to be a major determinant of subsequent obesity and non-communicable diseases. Short leg length relative to stature during adulthood seems to be a good proxy indicator tracking such barriers, and has been reported to be associated with adverse health effects during adulthood. Our objective was to examine the association between relative leg length (as measured …

Sub-Region Based Radiomics Analysis For Survival Prediction In Oesophageal Tumours Treated By Definitive Concurrent Chemoradiotherapy, Congying Xie, Pengfei Yang, Xuebang Zhang, Lei Xu, Xiaoju Wang, Xiadong Li, Luhan Zhang, Ruifei Xie, Ling Yang, Zhao Jing, Hongfang Zhang, Lingyu Ding, Yu Kuang, Tianye Niu, Shixiu Wu

Health Physics and Diagnostic Sciences Faculty Research

Background: Evaluating clinical outcome prior to concurrent chemoradiotherapy remains challenging for oesophageal squamous cell carcinoma (OSCC) as traditional prognostic markers are assessed at the completion of treatment. Herein, we investigated the potential of using sub-region radiomics as a novel tumour biomarker in predicting overall survival of OSCC patients treated by concurrent chemoradiotherapy. Methods: Independent patient cohorts from two hospitals were included for training (n = 87) and validation (n = 46). Radiomics features were extracted from sub-regions clustered from patients' tumour regions using K-means method. The LASSO regression for ‘Cox’ method was used for feature selection. The survival prediction model …