Other Medical Sciences Commons^™

Retrospective Comparison Of Prostate Vmat Boost Plans With Central Versus Offset Isocenter Placement, Carly Shefffield

Masters Projects

This retrospective study evaluated the effects of isocenter placement on dosimetric outcomes for sequential prostate boost planning using volumetric modulated arc therapy (VMAT). Ten patients previously treated with whole pelvis radiation therapy (WPRT) followed by a sequential boost were selected. For each patient, two VMAT boost plans were created using identical planning objectives and beam arrangements. One plan was optimized using the original WPRT isocenter, while the second plan had the isocenter placed at the center of the boost planning target volume (PTV). Target coverage, conformity, and organ-at-risk (OAR) dose metrics were compared between the two planning techniques. Both plans …

Impact Of Anatomical Changes On Treatment Plan Robustness: A Comparative Study Of Intensity Modulated Proton Therapy And Volumetric Modulated Arc Therapy In Head And Neck Cancer., Jennifer Croft

Masters Projects

Head and neck cancer patients often experience anatomical changes during radiation therapy, including weight loss and tumor regression. These changes can alter planned dose distribution and affect treatment accuracy. Based on the previous understanding, IMPT offers highly conformal dose delivery but is sensitive to the patient’s geometry changes and daily setup uncertainties, while VMAT may provide greater stability under these uncertainties. However, as of today, there is no quantitative analysis and comparison between the two modalities using real clinical data. The purpose of this study is to compare the robustness of IMPT and VMAT for head and neck cancer by …

Dosimetric Evaluation Of Clearsight Bolus Versus Superflab Bolus For Vmat Head And Neck Treatment, Courtney M. Williams

Masters Projects

This study compares the dosimetric performance and fit accuracy of ClearSight and Superflab boluses in head and neck (HN) volumetric modulated arc therapy (VMAT) treatment plans, focusing on dose distribution and air gap volumes. A RANDO anthropomorphic phantom was used to simulate HN VMAT treatment for oral cavity cancer with positive lymph nodes, prescribed 70 Gy in 35 fractions. Four configurations were tested: ClearSight bolus over a thermoplastic mask (CSO), ClearSight under a mask (CSU), Superflab over a mask (SFO), and Superflab under a mask (SFU). Five computed tomography (CT) scans, one without bolus and four with bolus, were performed …

Dosimetric Comparisons For Determining Optimal Arc Geometry In Multi Target Thoracic Vmat Sbrt Treatment Plans For Patients With Locally Advanced Inoperable Nsclc, Alexandrea M. Reeves

Masters Projects

Non-coplanar beam arrangements have been used for many years in radiation treatment planning. Their use has been known to show an increase in target conformity and gradient index. However, by using non-coplanar beam arrangements, the treatment planning time as well as the treatment delivery time can increase. Despite the increase in treatment planning and delivery complexity and time, previous studies have shown a decrease in OAR doses resulting in a desire to use non-coplanar beams. Previous studies have looked at various body sites and target locations, though no research has been found specifically studying non-coplanar beam arrangement in multi-target treatment …

A Dosimetric Comparison Of Treatment Techniques For Stereotactic Body Radiotherapy For Pancreatic Patients, Kameron Lemley

Masters Projects

Stereotactic body radiotherapy (SBRT) is utilized in radiation therapy to deliver ablative radiation doses to tumor volumes while achieving high conformity and minimal dose to surrounding critical structures. This treatment technique allows for faster dose fall-off which allows tighter treatment margins. SBRT for pancreatic cancer has been investigated for its efficacy and has proven to be an effective treatment choice for neoadjuvant radiation therapy. Since pancreatic cancer is extremely aggressive with a high mortality rate, it is important to have a treatment option that can reduce cost and increase convenience for the patient while simultaneously providing a conformal treatment plan. …

Comparative Plan Analysis: Helical Tomotherapy Vs. Linac Vmat For Lower Extremity Sarcomas, Marie E. Dibona

Masters Projects

Abstract

Introduction

Soft tissue sarcomas (STS) affect about 13,500 people annually in the United States, and those in the lower extremities present unique challenges in radiation therapy due to the wide variability in tumor sizes, sometimes exceeding 30cm. Traditional treatment involves C-Arm linear accelerators using Volumetric Modulated Radiation Therapy (VMAT), which provides precise targeting while sparing nearby organs. Helical Tomotherapy (HT) is another option, delivering radiation in a helical pattern with a binary MLC for a uniform dose distribution. However, no studies have compared VMAT and HT for lower extremity sarcomas of different sizes. This study aims to compare these …

Quantitative Benefits Of Reducing The Inferior Border Of Right-Sided Free Breathing Intact Breast Treatment Plans Regarding Liver Dose, Shelby Handshue

Masters Projects

Introduction

Breast cancer is a prevalent disease in the United States, affecting approximately one in eight women during their lifetime (Leaver & Washington, 2010). Advancements in medical treatments have evolved from mastectomy to a multidisciplinary approach. Radiation therapy plays a crucial role in preventing local recurrence after breast conserving surgery. Traditionally, whole breast irradiation has been administered over 25-28 fractions to a total dose of 45-50 Gray (Gy), followed by a boost of 5-8 fractions to the tumor bed. In recent times, hypofractionation, which involves a shorter treatment schedule of 15-16 fractions to a total dose of 42.5 Gy, followed …