Analytical, Diagnostic and Therapeutic Techniques and Equipment Commons^™

Clinical Impact Of Couch To P And Rails On Imrt And Arc Therapy, Kiley B. Pulliam

Dissertations and Theses (Open Access)

Purpose: To evaluate the clinical impact of the Varian Exact Couch on dose and volume coverage to targets and critical structures and tumor control probability (TCP) for 6-MV IMRT and Arc Therapy.

Methods: Five clinical prostate patients were planned with both, 6-MV 8-field IMRT and 6-MV 2-field RapidArc using the Eclipse treatment planning system (TPS). These plans neglected treatment couch attenuation, as is standard clinical practice. Dose distributions were then recalculated in Eclipse with the inclusion of the Varian Exact Couch (imaging couch top) and the rails in varying configurations. The changes in dose and coverage were evaluated using the …

The Effect Of Shoulder Variation On Imrt And Smartarc For Head And Neck Cancer, Emily H. Neubauer

Dissertations and Theses (Open Access)

Purpose: First, to determine an average and maximum displacement of the shoulder relative to isocenter over the course of treatment. Second, to establish the dosimetric effect of shoulder displacements relative to correct isocenter alignment on the dose delivered to the target and the surrounding structures for head and neck cancer patients.

Method and Materials: The frequency of shoulder shifts of various magnitudes relative to isocenter was assessed for 4 patients using image registration software. The location of the center of the right and left humeral head relative to isocenter (usually C2) was found daily from CT on rails scans, and …

The Development And Implementation Of An Anthropomorphic Head Phantom For The Assessment Of Proton Therapy Treatment Procedures, Paige A. Summers

Dissertations and Theses (Open Access)

Proton therapy has become an increasingly more common method of radiation therapy, with the dose sparing to distal tissue making it an appealing option, particularly for treatment of brain tumors. This study sought to develop a head phantom for the Radiological Physics Center (RPC), the first to be used for credentialing of institutions wishing to participate in clinical trials involving brain tumor treatment of proton therapy. It was hypothesized that a head phantom could be created for the evaluation of proton therapy treatment procedures (treatment simulation, planning, and delivery) to assure agreement between the measured dose and calculated dose within …

Evaluation Of Intensity Modulated Radiation Therapy (Imrt) Delivery Error Due To Imrt Treatment Plan Complexity And Improperly Matched Dosimetry Data, Jacqueline R. Tonigan

Dissertations and Theses (Open Access)

Intensity modulated radiation therapy (IMRT) is a technique that delivers a highly conformal dose distribution to a target volume while attempting to maximally spare the surrounding normal tissues. IMRT is a common treatment modality used for treating head and neck (H&N) cancers, and the presence of many critical structures in this region requires accurate treatment delivery. The Radiological Physics Center (RPC) acts as both a remote and on-site quality assurance agency that credentials institutions participating in clinical trials. To date, about 30% of all IMRT participants have failed the RPC’s remote audit using the IMRT H&N phantom. The purpose …

Tp53 As A Biomarker In Head And Neck Squamous Cell Carcinoma, Thomas J. Ow Md

Dissertations and Theses (Open Access)

Currently, there are no molecular biomarkers that guide treatment decisions for patients with head and neck squamous cell carcinoma (HNSCC). Several retrospective studies have evaluated TP53 in HNSCC, and results have suggested that specific mutations are associated with poor outcome. However, there exists heterogeneity among these studies in the site and stage of disease of the patients reviewed, the treatments rendered, and methods of evaluating TP53 mutation. Thus, it remains unclear as to which patients and in which clinical settings TP53 mutation is most useful in predicting treatment failure.

In the current study, we reviewed the records of a cohort …

Evaluation Of The Quantitative Accuracy Of A Commercially-Available Positron Emission Mammography Scanner, Adam Springer

Dissertations and Theses (Open Access)

Objective: The PEM Flex Solo II (Naviscan, Inc., San Diego, CA) is currently the only commercially-available positron emission mammography (PEM) scanner. This scanner does not apply corrections for count rate effects, attenuation or scatter during image reconstruction, potentially affecting the quantitative accuracy of images. This work measures the overall quantitative accuracy of the PEM Flex system, and determines the contributions of error due to count rate effects, attenuation and scatter.

Materials and Methods: Gelatin phantoms were designed to simulate breasts of different sizes (4 – 12 cm thick) with varying uniform background activity concentration (0.007 – 0.5 μCi/cc), cysts and …

Effect Of Acute Administration Of Angiopoietin-1 In Experimental Traumatic Spinal Cord Injury: Magnetic Resonance Imaging And Neurobehavioral Studies, Chirag B. Patel

Dissertations and Theses (Open Access)

Spinal cord injury (SCI) is a devastating condition that affects people in the prime of their lives. A myriad of vascular events occur after SCI, each of which contributes to the evolving pathology. The primary trauma causes mechanical damage to blood vessels, resulting in hemorrhage. The blood-spinal cord barrier (BSCB), a neurovascular unit that limits passage of most agents from systemic circulation to the central nervous system, breaks down, resulting in inflammation, scar formation, and other sequelae. Protracted BSCB disruption may exacerbate cellular injury and hinder neurobehavioral recovery in SCI.

In these studies, angiopoietin-1 (Ang1), an agent known to reduce …

Commissioning An Anthropomorphic Spine And Lung Phantom For Remote Dose Verification Of Institutions Participating In Rtog 0631, Douglas F. Caruthers

Dissertations and Theses (Open Access)

The RPC developed a new phantom to ensure comparable and consistent radiation administration in spinal radiosurgery clinical trials. This study assessed the phantom’s dosimetric and anatomic utility. The ‘spine phantom’ is a water filled thorax with anatomy encountered in spinal radiosurgery: target volume, vertebral column, spinal canal, esophagus, heart, and lungs. The dose to the target volume was measured with axial and sagittal planes of radiochromic film and thermoluminescent dosimeters (TLD). The dose distributions were measured with the radiochromic film calibrated to the absolute dose measured by the TLD. Four irradiations were administered: a four angle box plan, a seven …

Mechanism-Based Strategies To Enhance The Actions Of A, Fabiola C. Gomez

Dissertations and Theses (Open Access)

Heat shock protein 90 (HSP90) is an abundant molecular chaperone that regulates the functional stability of client oncoproteins, such as STAT3, Raf-1 and Akt, which play a role in the survival of malignant cells. The chaperone function of HSP90 is driven by the binding and hydrolysis of ATP. The geldanamycin analog, 17-AAG, binds to the ATP pocket of HSP90 leading to the degradation of client proteins. However, treatment with 17-AAG results in the elevation of the levels of antiapoptotic proteins HSP70 and HSP27, which may lead to cell death resistance. The increase in HSP70 and HSP27 protein levels is due …

Characterization And Optimization Of Antigen-Specific T Cell Responses During Ex Vivo Expansion Of Melanoma Tumor-Infiltrating Lymphocytes, Yufeng Li

Dissertations and Theses (Open Access)

Treatment of metastatic melanoma with tumor reactive T cells (adoptive T cell therapy, ACT) is a promising approach associated with a high clinical response rate. However, further optimization of this treatment modality is required to increase the clinical response after this therapy. ACT in melanoma involves an initial phase (pre-REP) of tumor-infiltrating lymphocyte (TIL) expansion ex vivo from tumor isolates followed by a second phase, “rapid expansion protocol” (REP) generating the billions of cells used as the TIL infusion product. The main question addressed in this thesis was how the currently used REP affected the responsiveness of the CD8+ T …

Influence Of Anchoring On Miscarriage Risk Perception Associated With Amniocentesis, Regina A. Nuccio

Dissertations and Theses (Open Access)

INFLUENCE OF ANCHORING ON MISCARRIAGE RISK PERCEPTION ASSOCIATED WITH AMNIOCENTESIS Publication No. ___________ Regina Nuccio, BS Supervisory Professor: Claire N. Singletary, MS, CGC Amniocentesis is the most common invasive procedure performed during pregnancy (Eddleman, et al., 2006). One important factor that women consider when making a decision about amniocentesis is the risk of miscarriage associated with the procedure. People use heuristics such as anchoring, the action of using a prior belief regarding the magnitude of risk as a frame of reference for new information to be synthesized, to better understand risks that they encounter in their lives. This study aimed …