Medicine and Health Sciences Commons^™

Spinal Cord Dose Reduction Using A Jaw-Blocking Vmat Technique - A Retrospective Study Of Chordoma And Chondrosarcoma Patients, Amber Wyatt

Culminating Experience Projects

Chordomas and chondrosarcomas are rare tumors that commonly experience loco-regional recurrence after primary treatment, making management of these tumors complex and difficult. Published case series reporting post-surgical outcomes for chordoma indicate that loco-regional recurrence affects more than 50% of patients treated with macroscopic complete resection with or without RT. Notably, a high proportion of recurrences occur late (after 5 and 10 years), requiring long-term follow-up. Chordomas and chondrosarcomas are considered to be radioresistant and require high doses of radiation greater than 60 Gy (Catanzano et al., 2019). There is a little data available regarding the most effective way to minimize …

A Quantitative Investigation Of Treating Lung Tumors With Dynamic Conformal Arcs Vs. Vmat For Lung Sbrt Plans, Shawn Loutos

Culminating Experience Projects

Introduction

This study aims to investigate the comparisons in dynamic conformal arc, VMAT (no ASC), forced MU limitations (ASC), or a 50/50 hybrid arc (ASC) in how they can improve a lung SBRT case where the tumor is abutting a dose critical structure. The goal of this research is to investigate multiple treatment techniques in an attempt to increase the dose constraint pass rate. The variables in comparison are how well different plan iterations can successfully meet constraints as well as pass a 0.5 modulation complexity score (MCS).

Methods

10 previously treated patients were used in this study who exhibited …

Quantifying The Dosimetric Impact Of Target Margins In The Oligometastatic Setting, Jessica E. Strang

Culminating Experience Projects

Introduction

With advancements in cancer treatment therapies, patients are living longer with oligometastatic disease. These patients may have multiple targets and may be treated in a single isocenter to reduce overall treatment time. However, the most considerable risk of treating multiple lesions in a single isocenter is a geometric miss. It can be challenging to perform daily alignment of multiple lesions creating a need to prioritize one lesion alignment over others or abort treatment.

Methods

This study quantified the dosimetric impact of total lung exposure as the planning target volume (PTV) margin incrementally increased for multiple intrathoracic lesions.

The analysis …

Deep Inspiration And End Exhale Breathhold Evaluation For The Treatment Of Locally Advanced Pancreatic Adenocarcinoma Using The Viewray Mridian Linactm, Tatum Mcglynn

Culminating Experience Projects

Introduction

Radiation therapy has been limited in the treatment of locally advanced pancreatic cancer. This is due to the dose tolerance to nearby organs at risk and breathing motion. Advancements in radiation treatment technology have now allowed pancreatic patients to be treated to higher doses in fewer fractions using stereotactic body radiotherapy treatment. With the use of MRI-guided treatments, using the ViewRay MRIdian linac, doses can be escalated using online adaptive treatment planning and real time tracking. However, there has yet to be an optimal breathhold technique investigated that can aid in this process.

Methods

Five patients that had been …

Dosimetric Comparison Of Static Imrt And Vmat Apbi Treatment Planning In The Prone Position For Breast Conservation Therapy, Kelly A. Foucher

Culminating Experience Projects

Introduction

Prevalence of early-stage breast cancer is increasing with the aid of preventative screenings and early diagnosis. The standard of care is transforming from conventional approaches with long treatment regimens towards hypofractionation and tissue sparing techniques. Based on studies over the past ten years, there are reasons to consider a partial-breast, hypo fractionated treatment option in the supine position. In practice, aPBI is often produced using several static intensity modulated beams to control dose to the normal breast tissue and limit dose to the heart and lungs. Patients may also be treated in the prone treatment setup in order to …

Effects Of Ezfluence Planning Software On Dosimetric Parameter Compliance For Early-Stage Breast Cancer, Jackie Loomis

Culminating Experience Projects

Each year over 2 million women are given a breast cancer diagnosis and over half a million women succumb to the disease yearly. As technology advances in the world of radiation oncology, automated planning softwares, such as Radformation’s EZFluence, are being utilized to streamline the treatment planning process. This study was designed to investigate whether the automated plans are dosimetrically equivalent to traditionally planned 3D field in field tangential plans. Is there a disadvantage to using these automated softwares? Three different dosimetrists with varying backgrounds replanned 27 previously treated breast cancer patients and an assortment of comparisons were ran between …

Using Radformation Ezfluence Software To Simplify Three Field Breast Radiation Therapy Planning Compared To Field-In-Field Technique, Brianna L. Woodburn

Culminating Experience Projects

Purpose: To evaluate time savings, efficiency, and accuracy of an automated planning software.

Methods: 10 previously treated breast cancer patients with supraclavicular involvement were retrospectively planned using a monosiocentric field-in-field technique by both an automated treatment planning software and a human planner. Time spent on planning was recorded and after plans were generated, dose constraints and target coverage were measured to evaluate overall plan quality.

Results: Time spent for planning was significantly decreased when using a FIF plan generated by the automated planning software. CTV target coverage for both the breast and supraclavicular volumes and dose to OARs for both …

An Evaluation Of Methods To Reduce Inframammary Surface Dose In Prone Breast Irradiation, Seth Alvarado

Doctoral Dissertations

In cases of breast radiation treatments via external beam radiation therapy, the incidence of radiation dermatitis has been reported. In prior studies, this acute radiation side-effect has been correlated with the immobilization devices in cases of prone breast irradiation. They attribute this to the bolus effect that occurs with the interaction of the incident photon beam at different projections causing an increase in measured surface dose. The type of radiation planning technique, and patient positioning during the undertaking of these techniques, have also shown to influence this bolus effect. This study focuses on these factors in treatment planning in order …

A Quantitative Comparison Of Linac Vs. Cyberknife For Sbrt Prostate Boost: A Retrospective Study, Vicente Miguel Ornelas

Culminating Experience Projects

Purpose: The purpose of this study is to retrospectively evaluate the quantitative difference of prostate SBRT boost between LINAC boost and CK boost treatments, with a primary plan using LINAC volumetric modulated arc therapy.

Materials and Methods: Nine prostate cancer patients were treated with a SBRT fractionated schedule of 21 Gy in 3 fractions, given every other day over the course of a week. The LINAC-BOOST were created by the researcher followed the same fractionation schedule, treatment volumes, OAR, and dose constraints as the original CK-BOOST treatment. The CK-BOOST was completed on the Multiplan (v14) TPS, while the LINAC-BOOST was …

An Evaluation Of Methods To Reduce Inframammary Surface Dose In Prone Breast Irradiation, Seth Alvarado

Culminating Experience Projects

In cases of breast radiation treatments via external beam radiation therapy, the incidence of radiation dermatitis has been reported. In prior studies, this acute radiation side-effect has been correlated with the immobilization devices in cases of prone breast irradiation. They attribute this to the bolus effect that occurs with the interaction of the incident photon beam at different projections causing an increase in measured surface dose. The type of radiation planning technique, and patient positioning during the undertaking of these techniques, have also shown to influence this bolus effect. This study focuses on these factors in treatment planning in order …

A Dosimetric Evaluation Of Skin Dose In Post Mastectomy Radiation Therapy: A Comparison Of Static Field Intensity Modulated Radiation Therapy And Volumetric Modulated Arc Therapy, Dusti M. Henion

Culminating Experience Projects

Introduction

Post mastectomy radiation therapy can cause significant skin reaction for patients treated with bolus. The elimination of bolus as a standard practice for this treatment has been suggested in recent literature. Additionally, volumetric modulated arc therapy (VMAT) may deliver a comparable plan with the benefit of reducing treatment times for this population compared to static field intensity modulated radiation therapy (IMRT).

Methods

This study is a retrospective dosimetric analysis of ten right-sided postmastectomy radiation therapy patients. The subjects had previously completed a course of radiation therapy consisting of static field IMRT with the use of bolus every other day …

A Quantitative Investigation At Dose To Tissue When Using Physical Constraints Versus Biological Based Constraints In Pancreatic Carcinoma Patients, Kelly R. Alley

Culminating Experience Projects

Introduction

The purpose of this study was to compare dose to organs at risk as well as PTV coverage. Physical objectives, biological objectives, and a combination of the two were utilized to compare which technique provided the best coverage of the PTV while also preserving the greatest amount of healthy tissue.

Methods

Each randomly selected patient had three separate plans created for them. The first plan used only physical based constraints in the form of upper objectives. The second plan used only biological based constraints in the form of gEUD objectives. The third plan used a combination of both upper …