Physics Commons^™

Abhd5 Induced Morphological Changes On Model Membrane Systems, Nasser S. Junedi

Honors College Theses

Proper regulation of neutral lipid storage (lipogenesis) and release (lipolysis) are critical molecular processes localized to an organelle called the Lipid Droplet (LD). The LD consists of a core with neutral lipids such as triacylglycerols (TAGs) and sterol esters surrounded by a phospholipid monolayer. Dysregulation of the processes localized to the LD are involved in the pathology of various diseases such as Neutral Lipid Storage Disease, diabetes, stroke and cancer. The non-enzymatic protein ABHD5 (α-β Hydrolase Domain-Containing Protein 5), is thought to play a key role in the process of lipolysis by forming homo-oligomers on the surface of the LD …

High Frequency Percussive Ventilation For Tumor Motion Immobilization, Ina Marina Sala

Wayne State University Dissertations

This work investigates the use of High Frequency Percussive Ventilation as a technique for respiratory motion mitigation in radiotherapy. This technique was extensively investigated in several prospective and retrospective studies.

In an initial prospective study, we evaluated the feasibility of HFPV and chest-wall motion reduction, by recruiting 15 healthy volunteers to undergo HFPV with three commercially available interfaces. For direct tumor motion immobilization, a second prospective study was performed in which with ten lung cancer patients underwent HFPV while imaged with high frame rate fluoroscopy. Diaphragm motion and image artifacts were quantified in a prospective study of a healthy volunteer …

Utilizing Log Files For Treatment Planning And Delivery Qa In Radiotherapy, Carl W. Stanhope

Wayne State University Theses

Purpose: Monte Carlo-based log file quality assurance (LF-MC QA) is investigated as an alternative method to phantom-based patient-specific quality assurance in radiotherapy (e.g. ArcCHECK QA (AC QA)).

Methods: First, the shortcomings of AC QA were investigated. The sensitivity dependence of ArcCHECK diodes on dose rate (in-field) and energy (primarily out-of-field) was quantified. LF-MC QA was then analyzed on the phantom geometry. Planned (‘Plan’) and LF-reconstructed CS and MC doses were compared with each other and AC measurement via statistical (mean ± StdDev(σ)) and gamma analyses to isolate dosimetric uncertainties and quantify the relative accuracies of AC QA and LF-MC QA. …

Kilovoltage Intensity Modulated Radiotherapy, Brian Loughery

Wayne State University Dissertations

Contrast enhanced kilovoltage radiotherapy could be a significant improvement over the standard of care in glioblastoma multiforme, but its potential benefit has been hindered by fears of insufficient dose falloff, high skin and skull dose, contrast delivery concerns, and high cost. This dissertation aims to address the validity of these fears.

Contrast delivery concerns are examined by assuming that sufficient dose can be safely delivered to the tumor. Iodine, gadolinium, and gold nanoparticle biological effect and delivery research is examined and the ideal contrast delivery methods are reported. Dose falloff and skull dose are then investigated through treatment planning and …

Clinical Applications Of Advanced Rotational Radiation Therapy, Adrian Nalichowski

Wayne State University Dissertations

Purpose: With a fast adoption of emerging technologies, it is critical to fully test and understand its limits and capabilities. In this work we investigate new graphic processing unit (GPU) based treatment planning algorithm and its applications in helical tomotherapy dose delivery. We explore the limits of the system by applying it to challenging clinical cases of total marrow irradiation (TMI) and stereotactic radiosurgery (SRS). We also analyze the feasibility of alternative fractionation schemes for total body irradiation (TBI) and TMI based on reported historical data on lung dose and interstitial pneumonitis (IP) incidence rates.

Methods and Materials: An anthropomorphic …

Principal Component Analysis-Based Anatomical Motion Models For Use In Adaptive Radiation Therapy Of Head And Neck Cancer Patients, Mikhail Aleksandrovich Chetvertkov

Wayne State University Dissertations

Purpose: To develop standard and regularized principal component analysis (PCA) models of anatomical changes from daily cone beam CTs (CBCTs) of head and neck (H&N) patients, assess their potential use in adaptive radiation therapy (ART), and to extract quantitative information for treatment response assessment.

Methods: Planning CT (pCT) images of H&N patients were artificially deformed to create “digital phantom” images, which modeled systematic anatomical changes during Radiation Therapy (RT). Artificial deformations closely mirrored patients’ actual deformations, and were interpolated to generate 35 synthetic CBCTs, representing evolving anatomy over 35 fractions. Deformation vector fields (DVFs) were acquired between pCT and synthetic …