Radiation Medicine Commons^™

Urgent Radiotherapy For Superior Vena Cava Syndrome In Metastatic Non-Small Cell Lung Cancer: A Case Report, Arpeet Patel, Nilanjan Haldar, Ida Micaily, Michael Greenberg, Evan Nardone, John A. Lippert, Christopher Fundakowski, Adam C. Mueller

Department of Radiation Oncology Faculty Papers

Superior vena cava (SVC) syndrome is a life-threatening complication of thoracic malignancies, requiring rapid management in the setting of airway compromise or hemodynamic instability. We present a 59-year-old male with metastatic non-small cell lung cancer (NSCLC) who developed superior vena cava syndrome (SVCS) due to compression from a large mediastinal mass identified as metastatic lung adenocarcinoma. His declining respiratory status progressed rapidly, necessitating intensive care. After extensive multidisciplinary collaboration, the patient was determined fit for inpatient radiation therapy and 10 fractions of 300 cGy external beam radiotherapy to the obstructing lesion was planned. However, the patient was unable to lay …

Detection Of Phase-Binning And Interpolation Artifacts In 4-Dimensional Computed Tomography Imaging Using Deep Learning And Rule-Based Approaches, Jorge Cisneros, Nathan H. Feldt, Yevgeniy Vinogradskiy, Richard Castillo, Edward Castillo

Department of Radiation Oncology Faculty Papers

BACKGROUND: Four-dimensional computed tomography (4DCT) imaging is a crucial component to lung cancer radiotherapy planning and enables CT-ventilation-based functional avoidance planning to mitigate radiation toxicity. However, 4DCT scans are frequently impaired by acquisition artifacts that corrupt downstream analyses that depend on lung segmentation and deformable image registration, such as CT-ventilation and dose accumulation.

PURPOSE: This study develops 3D deep learning models to identify phase-binning artifacts at the voxel level and a heuristic, rule-based method to identify interpolation slices within 4DCT images.

METHODS: We introduce a generator that systematically inserts synthetic phase-binning and interpolation artifacts into any artifact-free breathing phase obtained …

Integrating Spot-Scanning Proton Arc Therapy With Functional Avoidance Strategies To Reduce Pulmonary Toxicity, Yingxuan Chen, Peilin Liu, Xiaoda Cong, Edward Castillo, Richard Castillo, Inga Grills, Craig Stevens, Xiangkun Xu, Xiaoqiang Li, Yevgeniy Vinogradskiy, Xuanfeng Ding

Department of Radiation Oncology Faculty Papers

Background and purpose: Functional avoidance radiotherapy has emerged as a promising technique using functional imaging to minimize pulmonary toxicity by reducing doses to functional lung. This study aims to investigate the potential dose-volume advantages of a novel spot-scanning proton arc (SPArc) therapy for functional avoidance radiotherapy with four-dimensional computed tomography (4DCT)-based ventilation imaging.

Material and methods: Twenty-five patients from a prospective functional avoidance clinical trial treated with intensity-modulated photon radiotherapy were included. Robustly optimized intensity modulated proton therapy (IMPT) and SPArc plans were generated in RayStation. Functional lung contour was derived from the 4DCT-based ventilation imaging and utilized as an …

A Feasibility Study Of Sexual Organ-Dose Sparing Volumetric Modulated Arc Therapy In Female Low Rectal Cancer Patients Treated With Three-Dimensional Conformal Radiation Therapy, Margaret Downes, Victoria Olsen, Andre Williams, Rendi Sheu, Maria Thor, Lucy Greenwald, Vishruta Dumane, Kristin Hsieh, Ayesha Ali, Orly Morgan, Michael Buckstein, Deborah Marshall

Department of Radiation Oncology Faculty Papers

BACKGROUND: Sexual dysfunction is a significant toxicity of pelvic radiation therapy (RT) for female rectal cancer patients and may be more common with intensity-modulated techniques compared to three-dimensional conformal radiation therapy (3D-CRT). However, limited research has evaluated dose sparing of female sexual organs at risk (OARs), particularly erectile tissues that are critical for sexual function.

PURPOSE: This feasibility study aimed to demonstrate the practicality of contouring and sparing female sexual OARs in rectal cancer RT by generating sexual organ-sparing volumetric modulated arc therapy (SO-VMAT) plans from a small 3D-CRT cohort and comparing dose distributions to guide future planning.

METHODS: Nine …

From Standard To Stratified: Modeling Ntcp And Ear To Personalize Daily Mv-Cbct In Radiotherapy., Duong Thanh Tai, Luong Tien Phat, Tran Trung Kien, Duong Tuan Linh, Nguyen Ngoc Anh, Nguyen Quang Hung, Peter Sandwall, Parham Alaei, David Bradley, James C L Chow

Oncology Articles

PURPOSE: To evaluate the cumulative radiobiological impact of daily megavoltage cone-beam computed tomography (MV-CBCT) imaging dose based on normal tissue complication probability (NTCP) and excess absolute risk (EAR) of secondary malignancies among radiotherapy patients treated for breast, pelvic, and head & neck cancers. This study investigated whether MV-CBCT imaging dose warrants protocol personalization according to patient age, anatomical treatment site, and organ-specific radiosensitivity.

METHODS: This retrospective study included cohorts of breast (n = 30), pelvic (n = 17), and head & neck (n = 20) cancer patients undergoing radiotherapy with daily MV-CBCT. Imaging dose distributions employing two common MV-CBCT protocols …

Practical Real-Time Permanent Magnet Energy Spectrometer Using A Diode Array For Therapeutic Electron Beam Tuning And Quality Assurance, Mason W. Heath

LSU Doctoral Dissertations

Purpose: Develop a practical, real-time permanent magnet electron energy spectrometer and evaluate it for beam tuning and quality assurance (QA) of therapeutic electron beams.

Methods: Aim 1: A 0.55 T permanent magnet was coupled to Sun Nuclear SRS MapCHECK® PC boards, providing two interlaced diode arrays. Detector response, R_meas(z_diode) versus diode position z_diode, was extracted from raw diode array readings, correcting for diode sensitivity and other factors. Using Monte Carlo (MC) computed, monoenergetic detector response functions, a curve-fitting algorithm extracted the energy spectrum, from R_meas(z_diode). The energy spectra for 7-20 …

Clinical Characteristics Associated With Hospital Mortality And Length Of Stay Among Older Adults Admitted With Delirium: Retrospective Analysis, Se Won Lee, Jeff J. Kim, Cole Kretchmar, Napatkamon Ayutyanont, Mooyeon Oh-Park

HCA Healthcare Journal of Medicine

Background

Limited information exists on the characteristics of older adults admitted with delirium at risk of poor hospital outcomes. This study aims to identify risk factors present on admission that are associated with hospital mortality and length of stay (LOS) among older adults admitted with delirium.

Methods

This is a retrospective study of 5598 patients 65 years of age or older who were admitted to acute care units at 8 community hospitals with an International Statistical Classification of Diseases, Tenth Revision code of delirium.

Results

Multivariate regression analyses revealed that in-hospital mortality increase was associated with increased age, Asian race, …

Streamlining Nuclear Theranostic Clinic Workflow, Charisma Desai, Anne Fisher

Advances in Cancer Education and Quality Improvement

Nuclear medicine clinic needs have drastically changed with the emergence of theranostics, exciting new agents in the fight against cancer. However, administering these agents is a resource-intensive task, increasing demand for physician consultation time with patients, clinic office space, and scanner time. We examined our institution’s nuclear medicine clinic workflow and interviewed the clinic’s front desk staff, technologists, nurses, managers, physicians, and patients to find sources of delays, dissatisfaction, and decreased efficiency. An Ishikawa diagram and decision matrix helped us determine the most impactful intervention with our available resources. For this cycle, we focused on the consent process. Theranostic patients …

Enhancing Cyberattack Resiliency Through The Radiotherapy Backup And Recovery Dashboard Tool, Justin Pijanowski, Eric Nguyen, Yasin Abdulkadir, Justin Hink, Yevgeniy Vinogradskiy, James Lamb

Department of Radiation Oncology Faculty Papers

PURPOSE: Radiation Oncology departments impacted by recent cyberattacks were unable to access data backups or their Record and Verify (R&V) system and therefore faced challenges to resume patient treatments in a timely manner. We present a novel software tool that backs-up critical radiotherapy treatment information and displays essential information for on-treatment patients in an intuitive and accessible dashboard allowing clinics to continue radiotherapy treatments. The purpose of this report is to describe implementation details, challenges, and share open-source code to facilitate radiation oncology clinics' efforts to develop tools to improve cyberattack resiliency.

METHODS: The Radiotherapy Backup and Recovery Dashboard Tool …

Evaluation Of Image Quality In Mobile Cone-Beam Ct With Dose Modulation Using Automatic Exposure Control: A Phantom Study, Keita Okazaki, Wenchao Cao, Reza Taleei, Firas Mourtada, Jun Li, Karen Mooney, Pramila Rani Anne, Yingxuan Chen

Department of Radiation Oncology Faculty Papers

BACKGROUND: The integration of mobile cone-beam computed tomography (CBCT) into brachytherapy workflows offers clinical advantages such as immediate verification of applicator placement and adaptive treatment planning. These benefits require sufficient image quality to delineate applicators, target volumes, and organs at risk. A systematic evaluation of automatic exposure control (AEC) settings, radiation dose, and image quality is essential to ensure clinically acceptable imaging while minimizing patient exposure.

PURPOSE: This study evaluates the characteristics of AEC and its impact on image quality and radiation dose in a mobile CBCT system used for brachytherapy.

METHODS: The Elekta ImagingRing CBCT system was used to …

Clinical Outcomes Of Neoadjuvant Chemoimmunotherapy Vs. Chemoradiotherapy In Operable Non-Small Cell Lung Cancer, Tal Sherman, Nikta Nair, Marli Meller, Raleigh Anderson, Guillermo Jimenez, Elizaveta Flevora, Charalambos Solomides, Rita Axelrod, Sarah Gordon, Ida Micaily, Maria Werner-Wasik, Sung Whang, Tyler Grenda, Olugbenga Okusanya, Nathaniel R. Evans, Iii, Nilanjan Haldar, Erik Blomain

Department of Radiation Oncology Posters

Introduction

• Non-small cell lung cancer (NSCLC) accounts for ~85% of lung cancers and remains the leading cause of cancer death.
• Surgery is curative for early-stage disease, but recurrence rates remain high.
• CheckMate-816 trial established neoadjuvant chemo-immunotherapy (chemo-IO) as a new standard for resectable NSCLC, demonstrating improved pathologic response and event-free survival.
• PACIFIC trial showed the survival benefit of consolidative immunotherapy after chemoradiotherapy (chemo-RT) in unresectable stage III NSCLC, highlighting the synergy between radiation and immune checkpoint blockade.
• Despite these advances, there is little comparative data on the role of chemo-IO versus chemo-RT in the neoadjuvant, operable setting.
• Objective: To compare …

Anatomically Accurate, Low-Cost 3d-Printed Nasopharynx Simulator For Nasolaryngoscopy Training, Tal Sherman, Robert Walker, Voichita Bar-Ad, Firas Mourtada

Department of Radiation Oncology Posters

Introduction

- Flexible nasopharyngolaryngoscopy (NPL) is a core diagnostic and procedural skill in otolaryngology, radiation oncology, and related specialties. Early mastery is essential for safe patient care, but traditional training is limited by:

• Reliance on patient encounters, which may cause discomfort and restrict practice opportunities.
• High cost of commercial simulators(often $3,000–$5,000), restricting access across many programs.
• Lack of anatomical accuracyin available models, limiting their educational value.

- Gap: There is currently no accessible, anatomically faithful, and affordable tool for widespread trainee use.

- Objective: To design, fabricate, and validate a low-cost, anatomically accurate 3D-printed simulator for training in flexible NPL

Development And Validation Of An Ai-Based Lung Lobe Auto-Contouring Tool Using Radiation Therapy Planning Free-Breathing Images, Peter Ciaccio, Joseph Lombardo, Andrew Fuquay, Soroush Pahlavian, Rachel Grimm, Jun Kang, Wookjin Choi, Paul Sullivan, Yevgeniy Vinogradskiy

Department of Radiation Oncology Faculty Papers

BACKGROUND: Pulmonary toxicity can occur during radiation therapy of the lungs. Dose metrics evaluated at the lobar level can improve the ability to predict toxicity. Contouring lung lobes is challenging and time consuming. Currently there are limited dosimetry studies evaluating the dose to lung lobes. The purpose of this work was to develop and validate an artificial intelligence (AI) lung lobe auto-contouring algorithm using radiation therapy planning images.

MATERIALS AND METHODS: Fifty lung cancer patients from two institutions were analyzed, and a clinician contoured all five lung lobes [left upper lobe (LUL), left lower lobe (LLL), right upper lobe (RUL), …

Optimizing Palliative Spine Radiation: A Dosimetric Comparison Of Hybrid Arc Therapy And Conventional Appa Techniques, Alaina Vaneaton

Masters Projects

This study aimed to evaluate the dosimetric impact of Hybrid Arc Palliative Radiation Therapy (HART) versus conventional anterior-posterior/posterior-anterior (APPA) beam arrangements for thoracic spine metastases. The primary objective was to assess differences in conformity, homogeneity, and organ-at-risk (OAR) sparing between the two techniques. A retrospective plan comparison was conducted using anonymized datasets from twenty patients previously treated with HART. Each case was replanned using a standard APPA technique, normalized to match the target coverage of the original HART plan within 0.1%. All plans were prescribed 20 Gy in 5 fractions. Plan quality was evaluated using conformity index (CI), homogeneity index …

Enhancing Target Dose Conformity While Effectively Sparing The Spinal Cord In Proton Arc Treatment Plans For Cervical Chordomas And Chondrosarcomas, Jon Blalock

Masters Projects

Cervical spinal chordomas and chondrosarcomas present significant therapeutic challenges due to their proximity to the spinal cord and resistance to conventional radiotherapy. This retrospective study investigated the capability of proton arc therapy (PAT) to maintain or improve adequate target coverage while reducing dose to the spinal cord for cervical spinal chordomas and chondrosarcomas over standard fixed beam intensity modulated proton therapy (IMPT). While both IMPT and PAT use pencil beam scanning (PBS) to with energy modulation to deliver dose in discrete layers, IMPT relies on a limited number of fixed beam angles, whereas PAT delivers dose over an arc trajectory. …

Comparison Of Left Breast Accelerated Partial Breast Irradiation Plans: Flattening Filter Free Vmat Vs. Standard Vmat In Deep Inspiration Breath Hold And Free Breathing Techniques, Monica Albeck

Masters Projects

This retrospective planning study compared dosimetric outcomes and treatment efficiency between flattening filter free (FFF) and standard volumetric modulated arc therapy (VMAT) plans for left breast accelerated partial breast irradiation (APBI) under deep inspiration breath hold (DIBH) and free-breathing (FB) conditions. Ten patients with early stage left breast cancer were replanned to create four plans each: FFF VMAT and standard VMAT in DIBH and FB. All plans prescribed 30 Gy in 5 fractions. Measures included planning target volume (PTV) coverage, mean heart dose, ipsilateral lung V30%, contralateral breast maximum dose, and monitor units (MUs). Statistical analysis used repeated-measures ANOVA with …

Evaluating Dosimetric Outcomes In A Prostate Rapid Plan Model: A Comparison Of Prostate Treatment Plans With And Without Standardized Planning Structures, Erica Wartman

Masters Projects

Abstract

Knowledge-based planning (KBP) using RapidPlan (RP) has demonstrated the ability to produce high quality radiation therapy treatment plans while reducing time. This study evaluated whether the inclusion of department specific standardized planning structures, including rings and other optimization tools, improves plan quality when using a prostate and lymph node RP model, or if the model alone is sufficient to provide a quality plan without the use of these additional planning structures.

Ten previously treated Prostate+LN patients were replanned using the departmental RP model in Varian Eclipse treatment planning system.1 For each patient, two plans were created, one with standardized …

Evaluating Parotid Gland Dose Between Electronic Tissue Compensation And Field In Field Treatment Techniques For Parotid Sparing In Whole-Brain Radiotherapy, Joesph E. Bodgonas

Masters Projects

Purpose:

The parotid glands are essential to salivary function and patient quality of life, yet they are not routinely prioritized as organs at risk (OARs) during whole-brain radiotherapy (WBRT). With growing recognition of long-term side effects like xerostomia in patients with prolonged survival after WBRT, parotid-sparing techniques warrant investigation. This study compares radiation dose to the parotid glands using three different 3D conformal WBRT planning approaches: field-in-field (FiF) with blocking, electronic tissue compensation (eCOMP) without blocking, and eCOMP with blocking.

Methods and Materials:

A retrospective study was conducted on 20 patients previously treated with 3D conformal WBRT. Original eCOMP plans …

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 …

Radiation Induced Vaporization Of Exoskeletal Droplets As Potential X-Ray Acoustic Contrast Agents, Mohamed E. Eldib, William N. Frantz, Mark A. Borden, Ryan Lanning, Moyed Miften, David H. Thomas

Department of Radiation Oncology Faculty Papers

BACKGROUND: In vivo dosimetry is a crucial component of ensuring accurate and safe radiation therapy (RT) delivery, but many existing techniques face challenges such as low signal-to-noise ratio (SNR), which can limit their clinical applicability.

PURPOSE: In this study, we investigate a novel contrast agent sensitive to megavoltage (MV) radiation in vitro, ultimately aiming for in vivo dosimetry.

METHODS: Vaporizable exoskeletal droplets were engineered to phase-change into ultrasound-responsive microbubbles upon exposure to MV photon radiation. These droplets comprised a hydrocarbon (HC) exoskeleton doped with gold nanoparticles (GNPs) surrounding a liquid fluorocarbon (FC) core. Radiation absorbed by the GNPs induced localized …

Dosimetric Comparisons Of 6mv, 6fff, 10mv, And 10fff On Vmat Planning In Patients With Endometrial Cancer, Madisin M. Depas

Masters Projects

Purpose: This study aimed to evaluate the dosimetric and efficiency impacts of different photon beam energies—6MV, 6 flattening filter free (FFF), 10MV, and 10FFF—on volumetric modulated arc therapy (VMAT) plans for endometrial cancer, with attention to target coverage, organ at risk (OAR) sparing, and treatment efficiency.

Methods: A retrospective analysis was conducted on 25 patients with post-hysterectomy endometrial cancer. Each patient received four VMAT plans with varying energies. Planning metrics assessed included planning target volume (PTV) dose maximum (Dmax), conformity index (CI), heterogeneity index (HI), OAR doses (bladder, bowel, rectum), and total monitor units (MU). Correlations were drawn …

Dosimetric Effects Of Pinnacle³ Version 18.0 Advanced Auto-Planning Settings In Oropharyngeal Vmat Optimization, Emily Sanden

Masters Projects

This study evaluated the impact of Pinnacle³ version 18.0 auto-planning advanced settings modulation amount, monitor unit (MU) level, and dose fall-off priority on volumetric modulated arc therapy (VMAT) plan quality for bilateral oropharyngeal cancer. A total of 64 plans were generated using all possible combinations of low, medium, high, and very high settings for each parameter. A standardized base of tongue case was optimized once per plan using a single-time point approach, with planned target volume 1 (PTV1) (6996 cGy) and planned target volume 2 (PTV2) (5412 cGy) coverage evaluated. Each parotid gland, the spinal cord, brainstem, and the oral …

Impact Of Prostate Volume On Dose Fall-Off And Organ-At-Risk Exposure In Vmat For Prostate Cancer, Zhikang Jiang

Masters Projects

Prostate cancer remains one of the most prevalent malignancies among men, with radiotherapy, particularly VMAT—playing a central role in its management. VMAT allows for highly conformal dose delivery, but treatment planning must strike a careful balance between achieving steep dose gradients around the prostate and minimizing radiation exposure to nearby organs at risk (OARs), such as the bladder and rectum. This study aimed to evaluate how prostate volume influences dose fall-off characteristics and OAR dose exposure in VMAT treatment plans, providing insights into optimizing radiotherapy for patients with varying prostate sizes. A retrospective analysis was conducted on 50 prostate cancer …

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 …

Investigating The Necessity Of Adaptive Radiotherapy In Tomotherapy Of Head And Neck Cancer Patients, Ali Chaparian, Mahsa Kianinia, Mahnaz Roayaei, Nadia Najafizade, Abolfazl Kanani, Leili Mahani, Hamidreza Nourzadeh

Department of Radiation Oncology Faculty Papers

BACKGROUND: Anatomical variations that occur during radiation therapy in head and neck cancer (HNC) patients can lead to significant dosimetric changes. The purpose of this study is to evaluate dosimetric and volume changes in key anatomical structures for different treatment sites in HNC patients, and to determine the percentage of patients who need adaptive radiotherapy (ART) per treatment site.

METHODS: A total of 1,740 megavoltage computed tomography (MVCT) images from 58 HNC patients treated with helical tomotherapy (HT) were exported to the PreciseART™ (Accuray) software. Volume changes in the planning target volume (PTV) and the organs at risk (OARs) in …

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 …

Comparing And Evaluating Contralateral Breast Dose Relative To Median Ptv Tumor Bed Dose For Hypo-Fractionated Breast Treatments Using Import High Dose Constraints., Shannon J. Nordby

Masters Projects

This study is aimed to compare two different planning constraints for post-lumpectomy whole breast radiation treatments to evaluate whether or not the mean dose to the contralateral breast can be significantly reduced while maintaining plan quality for treatment. A total of 10 patients who had first undergone a lumpectomy were included into this study. Each patient’s initial treatment plan was created using a conventional approach with a mean dose constraint of < 600 cGy (Plan A) and then was replanned using the Import High protocol of a mean dose constraint, aiming to further push for a mean dose < 150 cGy (Plan B) to the contralateral breast. Both of these plans were analyzed for PTV coverage and dose to the surrounding critical structures. The results have shown that the contralateral mean dose was significantly reduced from an average of 216.32 in Plan A to 126.53 cGy in Plan B. All while meeting the target coverage of > 95% isodose line. Statistical testing showed a significant difference between the two planning techniques of lowering the contralateral dose (p < 0.0001), and normality testing supported the validity of the data analysis. In addition to a substantial dose reduction to the contralateral breast, Plan B maintained equal or improved dose constraint to other surrounding critical organs at risk, including the heart, lungs, spinal cord, and thyroid. The Import High protocol demonstrated consistent outcomes across diverse patient anatomies. These findings suggest that by using the Import High mean dose constraint, it is possible to maintain plan quality while reducing dose to the contralateral breast. This approach may help reduce the risk of long-term side effects and improve the patient’s overall outcomes in whole breast radiation treatments.

First Quantitative Investigation On The Dosimetric Perturbation From Dental Hardware In Spot-Scanning Proton Arc (Sparc®) Therapy And Planning Strategies In Head Neck Cancer Patient Population, Evan Harbert

Masters Projects

Purpose

There has been a tremendous interest in applying Spot-scanning Proton Arc (SPArc^®) to benefit head and neck cancer (HNC) patient population. However, the dental hardware materials effects on the beam distribution are not well understood, and placing spots through the dental hardware may cause an unnecessary degradation of target coverage if the material components differ from the nominal plan. The purpose of this study is to provide a quantitative dose perturbation analysis of the uncertainties caused by dental hardware and introduce a SPArc^® planning strategy to mitigate such impacts.

Methods and Materials

A published in-house developed …

Mechanistic Insights Into The Flash Effect: The Role Of Oxygen And Radiation Chemistry In Ultra-High Dose Rate Radiation Therapy, Jacob Pierce Sunnerberg

Dartmouth College Ph.D Dissertations

The development of new cancer therapies focuses on widening the therapeutic ratio between tumor control and normal tissue toxicity. Over the last decade, ultra-high dose rate (UHDR) radiation therapy, commonly known as FLASH radiotherapy (FLASH-RT), has shown promising potential to reduce normal tissue toxicity while maintaining tumor control. However, the underlying mechanisms of the FLASH effect remain poorly understood. This thesis explores the radiation-chemical basis of FLASH-RT, focusing on the role of oxygen and reactive oxygen species in modulating biological outcomes.

A comprehensive set of in vitro studies demonstrated that UHDR delivery significantly alters radiation chemistry compared to conventional dose …