Medicine and Health Sciences Commons^™

Post-Modeling Adjustments And Delivered Dose Verification Of The 6fff Beam Model Commissioned For The Monaco Treatment Planning System, Grant C. Debevec

LSU Master's Theses

External beam radiation therapy has been shown to be an effective treatment method for tumors and abnormalities of the spine and vertebral region. Treating the spine using a stereotactic body radiation therapy (SBRT) technique can reduce toxicity to the spinal cord. The 6 MV flattening filter free (6FFF) beam model is currently used to plan and calculate dose for SBRT treatment plans, and the treatment plans are delivered using a linear accelerator (LINAC).

The commissioned beam model represents an invariant component of a LINAC. For volumetric modulated arc therapy (VMAT) treatment plans, the multileaf collimator (MLC) positions are changing throughout …

The Theory Of X-Ray And Neutron Interferometry Using A Modulated Phase Grating, Hunter C. Meyer

LSU Master's Theses

Grating interferometry exploits wave interference to simultaneously image multiple physical properties of an object and can be performed using X-rays or neutrons. The modulated phase grating interferometer (MPGI) is a recently developed interferometry system that allows for the simultaneous acquisition of attenuation, differential-phase contrast, and dark-field images, which highlight X-ray or neutron absorption, refraction, and small angle scatter, respectively. This interferometry system uses a single grating, with a relatively high period envelope function, to produce interference fringes that can be directly resolved by standard high resolution detectors. The grating is sampled at a relatively low pitch, to meet coherence requirements …

Patient Specific Normalized Glandular Dose Range Estimate For Mammography, Lacey Medlock

LSU Master's Theses

Breast cancer is the most common type of cancer among women in the United States. It is also the second leading cause of death by cancer among women in the United States. Early detection is key to preventing fatalities. There are over 39 million mammography screening procedures performed yearly [3]. We know that exposure to radiation, including in routine mammography, may induce secondary cancers [4]. Thus, it is important to be able to accurately estimate the dose delivered to a patient during breast cancer screening. The dose delivered to a patient is regulated in the US and in many other …

Modeling Of Island Block Scatter For Intensity Modulated Bolus Electron Conformal Therapy, Joseph G. Scotto

LSU Master's Theses

Purpose: Bolus electron conformal therapy (BECT) benefits treatment of the post-mastectomy chest wall, head and neck, paraspinal muscles, and extremities. Patient dose heterogeneities caused by bolus can be reduced through intensity modulation (IM) across the incident electron beam. This requires passive radiotherapy intensity modulation for electrons (PRIME) devices, which utilize tungsten pins (island blocks) imbedded in machinable foam. IM-BECT treatment planning requires accurate dose calculation using the pencil beam redefinition dose algorithm (PBRA). Currently, the PBRA models island blocks as perfect collimators. This work explores models to account for electrons scattering into and out of the sides of island blocks. …

Modeling Cumulative Risk During The Covid-19 Pandemic: Psychosocial And Socioeconomic Factors For Older Minority Adults, James F. Osborne Iv

LSU Master's Theses

Continued response to the sum consequences of the COVID-19 pandemic has disparately affected the physical and mental health of older minority adults in the United States. SARS-CoV-2 created an acute epidemiological crisis of public health coinciding with a chronic pandemic of accentuated psychosocial stress. Biological and socio-economic risk of morbidity and mortality follow a demographic gradient of subjectively constructed social status that disproportionally threatens older adults and minority racial/ethnic communities. Pathways to increased socio-economic and psychosocial vulnerability are multifactorial and complex. Factors of race, socio-economic status, gender, and age, each contribute to individualized profiles of vulnerability to risk exposure.

The …

Predictive Modeling Of Fmol Health System Utilization Using Machine Learning Algorithms And Retrospective Study Of Covid Tested Patients, Ramyakrishna Tummala

LSU Master's Theses

Overutilization of Emergency Departments (ED) is a major problem among the health care providers in the United States. In this research, a machine learning-based predictive model for predicting ED high utilizers will be designed based on a set of existing and proposed facilities and the population and social determinant of health (SDOH) factors influencing utilization. The purpose of the model will be to alert the healthcare systems and government organizations by identifying the reasons for overutilization of the medical services among the people in a particular community. Also, the novel coronavirus disease 2019 (COVID-19) developed in Whunan city, China has …

Reconsidering The Obstetrical Dilemma: Correlations Between Head And Pelvic Size, Kelsey Catrice Fox

LSU Master's Theses

The Obstetrical Dilemma (OD) theory has become canon in biological anthropology. The OD posits that i] dystocia results from bipedal mothers and encephalized infants, ii] contrasting selection for bipedality and obstetrics hinders locomotive efficiency, and iii] the contradicting requirement of the fetus being small enough to pass through the birth canal yet being cognitively advanced enough to cling to its mother after birth. Females, theoretically, exhibit deficient gait efficiency for the sake of successful childbirth. An obstetric advantage theory has been posited where taller individuals with a larger head size have larger pelves. If the distance between the acetabulae increases …

Accessibility Of Hiv Testing In Baton Rouge Metropolitan Statistical Area, Alina Prigozhina

LSU Master's Theses

This study examines HIV testing accessibility in the Baton Rouge Metropolitan Statistical Area (BR MSA) using the two-step floating catchment area (2SFCA) method to calculate accessibility scores for free, low-cost and all other HIV testing facilities. The two goals of this research are to apply accessibility estimation methods to HIV testing facilities, and to examine the accessibility of HIV testing facilities in the BR MSA. To achieve these goals, this study uses several research methods. The data about HIV testing providers and their locations were collected through Internet searches. By means of a fieldwork, the data were checked, revealing that …

Evaluating Feline Release Criteria Following Iodine-131 Therapy For Hyperthyroidism, Anthony Davila

LSU Master's Theses

Hyperthyroidism is a very common endocrine disorder in both humans and cats. Radioactive iodine ablation therapy is considered the gold standard; however, the patient becomes a radiation source and poses a potential radiological risk to others. The regulations governing when the patient can be released differ between human medicine and veterinary medicine. A human patient can receive up to 33 mCi of I-131 and be discharged the same day; yet a feline patient can receive a dose as low as 2 mCi and require multiple days of hospitalization. This discrepancy has not been satisfactorily addressed; and overly restrictive release criteria …

Determination Of Scatter Fractions, Albedos, And Tenth Value Layers For Shielding Of Synchrotron Beamline Hutches, Bethany Lynn Broekhoven

LSU Master's Theses

Synchrotron facilities require substantial amounts of shielding to protect facility staff and researchers. To meet mandatory exposure limits, the traditional combination of time, distance, and shielding of the radiation source are utilized. Because of continuous 24-7 operation of most synchrotrons, time is the least useful tool. The experimental stations for synchrotron x-ray beamlines, called hutches, enforce a minimum distance from the source, but shielding provided by hutch walls is still the principal tool for a synchrotron facility. Currently there is no single resource for synchrotron beamline hutch shielding design in the literature; most hutch shielding is designed through either over-simplified …

Taking (Birth) Control: Empowerment Through Contraceptive Education, Meghan Saas

LSU Master's Theses

TAKING (birth) CONTROL is a body of work that educates women on their options for contraceptives, and empowers them to claim their right to choose if—and when—to have a child. Utilizing graphic design and letterpress printing processes, I created a visual system consisting of carefully honed typographic, color, and graphic styles. The bulk of the materials make up an educational toolkit for use at Delta Clinic of Baton Rouge, one of only three remaining abortion providers in Louisiana. Delta Clinic was in need of comprehensive and affordable materials for their patients on the subject of contraception. The toolkit consists of …

Identifying Key Factors Associated With High Risk Asthma Patients To Reduce The Cost Of Health Resources Utilization, Amani Ahmad

LSU Master's Theses

Asthma is associated with frequent use of primary health services and places a burden on the United States economy. Identifying key factors associated with increased cost of asthma is an essential step to improve practices of asthma management.

The aim of this study was to identify factors associated with over utilization of primary health services and increased cost via claims data and to explore the effectiveness of case management program in reducing overall asthma related cost.

Claims data analysis for Medicaid insured asthma patients in Louisiana was conducted. Asthma patients were identified using their ICD-9 and ICD-10 codes, forward variable …