Radiation Medicine Commons^™

Influence Of Lumpectomy Cavity Depth On Plan Quality In 3d Arc-Based Simultaneous Integrated Boost For Whole-Breast Radiotherapy, Emmett Dwyer

Masters Projects

Abstract

Purpose: Dynamic conformal arc (DCA) is a three-dimensional (3D) radiation therapy technique that can be used to deliver a simultaneous integrated boost (SIB) during whole-breast irradiation (WBI). This study investigated whether the depth of the lumpectomy cavity affects the feasibility of creating a successful DCA SIB treatment plan for breast radiotherapy.

Methods and Materials: 30 patients who previously received WBI followed by a 3D sequential boost (SeqB) were selected for this retrospective study. A DCA plan was created for each patient and combined with the original whole-breast tangent fields to create a SIB plan. Each plan was required to …

Effect Of Hydrogel Rectal Spacers On Bladder Wall And Regional Substructure Dose In Prostate Cancer Patients Undergoing Volumetric Modulated Arc Therapy With Simultaneous Integrated Boost: A Retrospective Planning Study, Geronimo Sosa

Masters Projects

Purpose: Hydrogel rectal spacers reduce rectal dose during prostate radiotherapy, but their effect on bladder wall dose is not well characterized, particularly with volumetric modulated arc therapy with simultaneous integrated boost (VMAT-SIB). This study evaluated the effect of spacer placement on whole and regional bladder wall dose.

Methods: Twenty-nine patients treated with VMAT-SIB (70 Gy in 28 fractions) were analyzed retrospectively: 9 with and 20 without a spacer. The bladder wall was defined as the whole bladder minus a 3-mm inner margin. Primary endpoints were D0.03 cc and D1 cc; secondary endpoints included D2 cc, D3 cc, D10 cc, volume-based …

Implementation Of Tg-351 Reference Dosimetry For A 6 Mv Photon Beam In An Mr-Guided Radiotherapy System, Nicholas A. Castellano Jr.

Theses and Dissertations

Magnetic resonance guided radiation therapy (MRgRT) combines magnetic resonance imaging (MRI) and radiation therapy to enable the visualization of anatomy in real time during treatment. The presence of a magnetic field in MRgRT affects charged particle radiation and detector responses, necessitating changes to traditional reference dosimetry procedures. The American Association of Physicists in Medicine (AAPM) Task Group 351 (TG-351) provides a formalism for reference dosimetry in MRgRT. In this study, the TG 351 formalism is used to perform reference dosimetry for a 6 MV flattening filter-free (FFF) photon beam from a Viewray MRIdian MR-Linac radiation therapy system. Beam quality determination, …

A Comparative Study Of Vmat Beam Arrangements In Large Field Nodal Prostate Treatment Plans, Laura R. Black

Masters Projects

Treatment of extensive prostate and pelvic lymph node volumes for prostate cancer patients provide unique challenges related to limitations in multileaf collimator (MLC) design in many modern linear accelerators. A strategy to overcome this challenge is by restricting the field size, improving modulation as well as using overlapping arcs to ensure complete coverage of the target. Using too few arcs can result in suboptimal target coverage, while too many arcs can lead to prolonged time on the table, increasing the risk of patient movement and potential side effects that may compromise treatment accuracy. This study aims to evaluate the optimal …

Evaluating Coplanar And Noncoplanar Treatment Plans For The Varian Halcyon And Varian Truebeam For Intact Prostate Patients., Ashley Coppage

Masters Projects

Prostate cancer is among the most treated malignancies with radiation therapy, where precise dose delivery is critical for tumor control and minimizing toxicity. VMAT is widely adopted due to its efficiency and conformity; however, the choice between coplanar and non-coplanar beam arrangements remains an area of ongoing investigation, especially with newer platforms like Halcyon and TrueBeam. This retrospective dosimetric study compares coplanar and non-coplanar volumetric modulated arc therapy (VMAT) treatment plans for intact prostate cancer patients using the Varian Halcyon and Varian TrueBeam systems. Plans were created using a standardized protocol within Eclipse v16.1, with all Halcyon plans employing coplanar …

Comparing Dosimetric Outcomes Of Static Imrt And Vmat In Accelerated Partial Breast Irradiation For Medially Located, Left-Sided Tumor Beds, Rani Jamil

Masters Projects

Abstract

Introduction: Accelerated partial breast irradiation (APBI) has emerged as a targeted alternative to whole-breast irradiation for early-stage breast cancer, particularly for patients with medially located, left-sided tumors. Static intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) offer advanced dose conformity, yet no direct comparisons between static IMRT and VMAT have been conducted specifically for medially located, left-sided APBI, a uniquely challenging anatomical subgroup. This study evaluates dosimetric differences between static IMRT and VMAT plans to determine which modality provides superior target coverage and organ-at-risk (OAR) sparing in left-sided APBI.

Methods: Ten patients with medially located left-sided breast …

Developing Real-Time, Online Beam Control Of Uhdr Irradiators To Facilitate Flash Translational Investigations, Austin M. Sloop

Dartmouth College Ph.D Dissertations

The field of radiation oncology seeks novel techniques to increase the therapeutic ratio to treat malignancies while minimizing damage and toxicities in healthy tissues. While it was observed that delivering therapeutic doses at high dose rate could elicit lower biological effects over a half-century ago, the field of ultra-high dose rate (UHDR) radiation therapy (colloquially known as FLASH RT) has seen a resurgence in recent years due to an alignment of accelerator capability, dosimetric advances, and improved biotechnological techniques. This has opened the door to studying potential underlying mechanisms such that we may leverage the effects of FLASH tissue sparing …

Optimization Processes Of Clinical Chelation-Based Radiopharmaceuticals For Pathway-Directed Targeted Radionuclide Therapy In Oncology, Katsumi Tomiyoshi, Lydia J. Wilson, Firas Mourtada, Jennifer Sims Mourtada, Yuta Namiki, Wataru Kamata, David J. Yang, Tomio Inoue

Department of Radiation Oncology Faculty Papers

Targeted radionuclide therapy (TRT) for internal pathway-directed treatment is a game changer for precision medicine. TRT improves tumor control while minimizing damage to healthy tissue and extends the survival for patients with cancer. The application of theranostic-paired TRT along with cellular phenotype and genotype correlative analysis has the potential for malignant disease management. Chelation chemistry is essential for the development of theranostic-paired radiopharmaceuticals for TRT. Among image-guided TRT,

Organ-Specific Dosimetry Following Radiopharmaceutical Therapy For Metastatic Prostate Cancer, Frank J. Arturi, Nilanjan Haldar, Shray Jain, Gia Nguyen, Jessie Dinome, Firas Mourtada, Lydia J. Wilson, Phd

Department of Radiation Oncology Posters

Introduction

• Radiopharmaceutical Therapy (RPT) uses radioactive agents to target cancer at the cellular level
• Lu-177 targeting prostate-specific membrane antigen (PSMA), known as 177Lu- PSMA-617, can be used to treat metastatic, castration-resistant prostate cancer (mCRPC)
• 177Lu-PSMA-617 treatments use a standard dose and treatment regimen for all patients
• Patients exhibit different side effects and tumor response during treatment

Can Simultaneous Integrated Boost Provide Better Dosimetric Coverage Compared To Sequential Boost In Prone Breast Treatment Of Large Breast Volumes?, Kinze Kraft

Masters Projects

Introduction: This study investigates the dosimetric differences between sequential boost (SeB) and simultaneous integrated boost (SIB) techniques in prone breast radiotherapy for patients with large breast volumes, utilizing a 3D-CRT planning technique. Prone positioning in radiotherapy has shown to be effective in reducing heart and lung doses, yet limited research exists to compare overall plan quality between SeB and SIB using this technique. This analysis aims to evaluate whether SIB provides better dosimetric coverage and reduced dose to organs at risk (OARs) compared to SeB in prone breast radiotherapy.

Methods: A retrospective analysis was conducted on data from ten patients …

Clinical And Dosimetric Impact Of 2d Kv Motion Monitoring And Intervention In Liver Stereotactic Body Radiation Therapy., Andrew Santoso, Yevgeniy Vinogradskiy, Tyler Robin, Karyn Goodman, Tracey Schefter, Moyed Miften, Bernard Jones

Department of Radiation Oncology Faculty Papers

PURPOSE: Positional errors resulting from motion are a principal challenge across all disease sites in radiation therapy. This is particularly pertinent when treating lesions in the liver with stereotactic body radiation therapy (SBRT). To achieve dose escalation and margin reduction for liver SBRT, kV real-time imaging interventions may serve as a potential solution. In this study, we report results of a retrospective cohort of liver patients treated using real-time 2D kV-image guidance SBRT with emphasis on the impact of (1) clinical workflow, (2) treatment accuracy, and (3) tumor dose.

METHODS AND MATERIALS: Data from 33 patients treated with 41 courses …

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

Masters 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 …

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

Masters 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 …