Radiation Medicine Commons^™

Software Tools And Simulation Exercises For Radiation Oncology Cyber-Attack Resiliency, Yevgeniy Vinogradskiy, James Lamb

Department of Radiation Oncology Faculty Papers

This review summarizes the rationale for radiation oncology cyberattack simulation exercises, recent results from multi-institutional resiliency drills, and the landscape of software tools developed to help clinics resume radiotherapy treatments rapidly and safely during a cyberattack or other major clinical software outage. Simulation exercises using record-and-verify (R&V) downtime and File Mode treatment delivery have identified failure modes not apparent in theoretical planning alone, including risks related to treatment documentation, repeated fractions, patient setup, and missed safety checks. Available software tools emphasize insulated backup of DICOM-format planning data and clinical notes, treatment-state dashboards, File Mode treatments, redundant R&V installations, and human-readable …

A Dosimetric Comparison Of Halcyon 6x-Fff And Truebeam 6x In Prone Left Whole Breast Radiation Therapy, Maritza Soto, Kelly Labant, M.S., Cmd, Rt(T), Kristen Vu, M.S., Cmd, Rt(T)

Masters Projects

Purpose:

This retrospective study compared dosimetric differences between prone left whole breast radiation (WBRT) treatment plans originally generated for Halcyon using 6X flattening- filter-free (FFF) beams and replanned for a conventional TrueBeam using 6X beams.

Methods:

Ten prone whole left breast treatment plans were paired and retrospectively analyzed. Clinically treated Halcyon 6X flattening filter free plans were replanned on TrueBeam using flattened 6X beams in Eclipse v16.1. Contours for all plans were generated using artificial intelligence-based autosegmentation, reviewed by a medical dosimetrist and radiation oncologist, and forward planned with a tangent technique in EZFluence to achieve identical planning objectives. Dose …

Dosimetric Comparison Between Geometric Centroid And Minimax Isocenter Placement In Single Isocenter Multitarget Stereotactic Radiosurgery Plans In Hyperarc, Matthew Gloudeman

Masters Projects

Single-isocenter multi-target (SIMT) stereotactic radiosurgery (SRS) utilizing Varian HyperArc streamlines clinical workflows but introduces geometric sensitivity for distant outlier lesions when rotational and setup uncertainties are taken into account. The default isocenter location in the HyperArc workspace is the geometric centroid, which is inherently biased toward clusters of lesions. This study evaluates the dosimetric plan quality of an alternative minimax isocenter strategy, which minimizes the maximum lesion-to-isocenter distance, shortening the rotational lever arm to enhance mechanical robustness. Two fractionated SRS (fSRS) plans were generated for ten patients with 3-5 brain metastases using identical beam configurations: one using HyperArc’s default geometric …

The Impact Of Scar Wires On Dose Distribution Of Electron Fields, Ahmad Nour

Masters Projects

Purpose: This phantom study looked at whether changing the Hounsfield unit (HU) value for radiopaque scar wires in Eclipse changed the calculated electron dose distribution. Methods and Materials: Radiopaque wires were placed in the same abdominal area on an anthropomorphic phantom. The wires were set up in a circle. The CT images were brought into Eclipse, the wires were contoured, and the planning target volume was made 1 cm inside the circle of wire. For every wire size and electron energy, two matching plans were made: one plan with no density override and one plan with a density override applied …

Dosimetric Comparison Of Hybrid 3d Conformal Radiation Therapy And Volumetric Modulated Arc Therapy Versus Vmat-Only Planning For Accelerated Partial Breast Irradiation, Erjona Jusufi

Masters Projects

Abstract

Purpose: To compare dosimetric outcomes between volumetric modulated arc therapy (VMAT)-only and hybrid VMAT plus three-dimensional conformal radiotherapy (3D-CRT) techniques for accelerated partial breast irradiation (APBI) in patients with early-stage left-sided breast cancer.

Methods and Materials: Thirty patients treated with APBI at a single institution were retrospectively replanned using both VMAT-only and hybrid (VMAT + 3D-CRT) techniques. All plans were prescribed 26 Gy in 5 fractions. Each patient was planned using the same target volumes, optimization objectives, and evaluation criteria for both techniques. Planning target volume (PTV) coverage, conformity index (CI), homogeneity index (HI), hotspot control, organ-at-risk (OAR) doses, …

Ai Integration In Radiotherapy Workflows: Emerging Trends And Best Practices, Vi T. Dinh

Radiologic Sciences

Purpose To synthesize current evidence on artificial intelligence (AI) integration in radiotherapy workflows, identify emerging application trends, and examine best practices for clinical implementation.

Method A structured literature review was conducted using PubMed, Scopus, and Google Scholar to identify peer-reviewed studies published between 2015 and 2025. Eligible studies evaluated AI applications in radiotherapy workflows, including segmentation, treatment planning, and clinical decision-making. Findings were synthesized using thematic analysis.

Results Three primary themes emerged: (a) AI-based segmentation improved contouring efficiency and reduced interobserver variability; (b) AI-assisted treatment planning enhanced dose prediction consistency and workflow reproducibility; and (c) workflow integration supported clinical decision-making …

Impact Of Mr-Linac Technology On Prostate Cancer Treatment Outcomes, Anhdiep P. Tran

Radiologic Sciences

Purpose To evaluate the impact of magnetic resonance-guided linear accelerator (MR-Linac) technology on treatment precision, clinical outcomes, and operational challenges in prostate cancer radiotherapy.

Method A systematic literature review was conducted using PubMed, Scopus, and Google Scholar to identify peer-reviewed studies published between 2018 and 2026. Eligible studies evaluated MR-Linac technology for prostate cancer and reported outcomes related to treatment precision, toxicity, workflow, and clinical effectiveness.

Results Three primary themes emerged: (a) improved treatment precision through superior soft tissue visualization, real-time target tracking, and adaptive radiotherapy; (b) improved clinical outcomes characterized by reduced radiation exposure to organs at risk, decreased …

Assault Vs. Assistance: Radiologic Technologist Decision-Making When Fall-Risk Patients Decline Assistance, Pamela O'Dowd

Radiologic Sciences

Purpose To explore how radiologic technologists experience and respond to situations involving fall-risk patients who decline assistance during imaging procedures.

Method A cross-sectional survey design was used to collect data from practicing radiologic technologists recruited through the American Society of Radiologic Technologists. Descriptive statistics, including frequencies and percentages, were analyzed using SPSS to summarize participant responses, and a thematic analysis was conducted on open-ended responses.

Results A total of 87 respondents completed the survey. Results indicated that encounters with fall-risk patients who refuse assistance are common in clinical imaging practice. Sixty-three (72.4%) technologists reported having experienced situations in which a …

Magnetic Resonance In Pregnancy: Safety Considerations, Contrast Risks, And Imaging Modality Alternatives, Lizzette Valdez

Radiologic Sciences

Purpose To examine the safety of magnetic resonance (MR) during pregnancy by evaluating fetal outcomes, contrast agent risks, and the comparative roles of MR, ultrasound, and computed tomography (CT) in prenatal imaging.

Method A literature review was conducted using PubMed and peer-reviewed radiology journals to identify studies evaluating MR safety during pregnancy. The review examined fetal and neonatal outcomes following prenatal MR exposure, trimester-specific imaging considerations, risks associated with gadolinium-based contrast agents, and comparisons among MR, ultrasound, and CT.

Results Three primary themes emerged: (a) noncontrast MR demonstrated a strong safety profile with no consistent association with adverse fetal or …

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 …

Ai-Driven Segmentation And Volumetric Response Modeling Of Liver Regions To Radiotherapy, Aashish Chandra Gupta

Dissertations and Theses (Open Access)

In liver-directed radiotherapy (RT), liver regions receiving higher doses typically undergo atrophy while contralateral/adjacent lower-dose regions may exhibit compensatory hypertrophy through regeneration of healthy tissue. Optimizing the RT plan to promote regional hypertrophy while minimizing the risk of developing atrophy has the potential to enhance post-RT liver function and long-term survivorship. However, current clinical practice largely relies on global liver dose-volume metrics during RT-planning, which may obscure favorable dose-response correlation and limit actionable guidance for clinicians. Therefore, we hypothesized that post-RT regional liver response is governed by a combination of region-specific dose-volume and patient clinical features, and that these responses …

Craniospinal Irradiation Volumetric Modulated Arc Therapy (Vmat) Planning: A Dosimetric Contrast Utilizing Anterior Avoidance Sectors, Ashleigh M. Sammataro

Masters Projects

Purpose: Craniospinal irradiation (CSI) is essential for treating pediatric and adult central nervous system malignancies, yet it exposes large volumes of normal tissue to low‑dose radiation, contributing to significant long‑term toxicity. This study evaluated whether incorporating anterior‑avoidance sectors (AVD) into volumetric modulated arc therapy (VMAT) planning would improve normal tissue sparing while maintaining target coverage and plan quality.

Materials and Methods: 8 previously treated CSI patients were retrospectively replanned using two VMAT techniques: Full Arc and AVD. All patients were simulated supine with standardized immobilization and planned in Eclipse. Identical target volumes, optimization structures, and planning objectives were used for …

Study On The Accuracy Of Varian Eclipse Mlc Modeling When Mlcs Are Open Beyond The Jaw In Breast Cancer Patient Planning Using Aaa And Acuros With Both Dual-Isocentric Technique And Mono-Isocentric Technique., Amy Rogers

Masters Projects

Accurate dose delivery at the chest wall-supraclavicular (CW-SCV) junction remains an important challenge in breast irradiation, especially when multileaf collimator (MLC) leaves are intentionally opened beyond the collimator jaws to improve junction coverage. This study evaluated the dosimetric accuracy of the Varian Eclipse treatment planning system (TPS) at the CW-SCV junction using the Anisotropic Analytical Algorithm (AAA) and Acuros XB calculation algorithms with mono-isocentric and dual-isocentric treatment techniques. A prospective phantom-based study was performed using a solid water phantom and a Varian TrueBeam linear accelerator. Twenty-four unique three-dimensional conformal treatment plan configurations were created using combinations of beam energy (6 …

Feasibility Evaluation Of Tumor Treating Fields For Brainstem Gliomas, Anthony Chen, Ryan Shah, William Shi, Noa Urman, Nadav Shapira, Nicholas Avgeropoulos, Patrick Conlon, Neil Mookerjee, Wenyin Shi

Department of Radiation Oncology Faculty Papers

PURPOSE: Tumor treating fields (TTFields) are FDA-approved for supratentorial glioblastoma, but feasibility in infratentorial tumors remains poorly defined. This simulation study evaluated TTFields dose in brainstem gliomas using patient-specific modeling with scalp-only transducer arrays.

METHODS: MRI and CT imaging from seven patients with brainstem gliomas were used for TTFields planning with MAXPOINT® (Novocure, Switzerland). Clinical target volume (CTV) was defined as enhancing tumor on T1 post-contrast MRI (Gross tumor volume, GTV) plus a 3 mm peritumoral expansion. The platform optimized scalp-only array layouts, and finite element calculations generated maps of local minimum field intensity (LMiFI, V/cm) and local minimum power …

Hypovascular Aggressive Angiomyxoma In A Pregnant Adolescent: A Case Report And Review Of Its Multimodal Imaging Appearances, Kyler Shin, Kweku Agyepong, Craig Kym, Mohammad Ghasemi-Rad, David Léon

Faculty, Staff and Students Publications

Aggressive angiomyxoma (AAM) is a rare mesenchymal tumor that primarily arises in the perineum and pelvis of young females. It is sometimes identified incidentally on pelvic examination and obstetric imaging. Although asymptomatic at small sizes, AAM is typically hypervascular and can grow large enough to complicate a patient's obstetric and gynecologic course of treatment. While AAM is a rare diagnosis reported in the literature, there are limited descriptions of its multimodal radiologic appearance, and uncommonly, it can present as a hypovascular mass. We describe a rare case of hypovascular AAM in pregnancy that did not respond favorably to targeted embolization, …

Blinded, Bias-Controlled Multi-Rater Evaluation Of Human-Versus-Ai Brain Metastasis Segmentation Using A Hybrid Foundation-Model Framework, Yiding Han, Enze Zhu, Mhd Hasan Ai Mekdash, Omar Awad, Piyush Pathak, Shixiao Liang, Daniel Allan Hamstra, Xizhe Zhang, Zaid Ali Siddiqui, Baozhou Sun

Faculty, Staff and Students Publications

Background: Accurate segmentation of brain metastases (BM) is essential for diagnosis, stereotactic radiosurgery planning, and longitudinal assessment. However, manual contouring is time-intensive, limiting clinical scalability, and exhibits substantial inter-observer variability. This variability complicates objective assessment of automated segmentation methods and challenges interpretation of model performance.

Purpose: To address these limitations, we developed TUM-SAM, a hybrid foundation-model framework for fully automated BM segmentation, and introduced a bias-controlled, blinded multi-rater evaluation paradigm to determine whether AI-based BM segmentation has reached expert-level performance and whether AI-generated contours are preferred by human experts under unbiased assessment.

Methods: TUM-SAM integrates nnU-Net-based lesion detection with a …

Fractionated Stereotactic Radiotherapy (Fsrt) For Symptomatic Who Grade 1 Cavernous Sinus Meningiomas: Long-Term Local Control, Clinical Response, And Toxicity Outcomes, Ryan Shah, Shray Jain, Nilanjan Haldar, Lauren A. Holt, Robert Walker, Christopher J Farrell, Md, Debanjan Haldar, James J. Evans, Gregory S. Alexander, Wenyin Shi

Department of Radiation Oncology Faculty Papers

PURPOSE: Cavernous sinus meningiomas represent a significant clinical challenge, given the high prevalence of neurological deficits and limited surgical options. Radiation therapy is often the preferred treatment. This study evaluates the effectiveness of fractionated stereotactic radiation therapy (fSRT) in achieving local control and symptomatic relief in patients with cavernous sinus meningiomas.

METHODS: This is a single-institution retrospective analysis of patients with symptomatic presumed WHO grade 1 cavernous sinus meningiomas treated with fSRT (1.8-2 Gy per fraction). Clinical data were collected by chart review. Kaplan-Meier curves were generated to assess local control. Clinical responses were evaluated for symptom improvement, stability, or …

Letter To The Editor: Hemodynamic Role In Hepatic Encephalopathy Pathogenesis Following Transjugular Intrahepatic Portosystemic Shunt Placement, John Halphen, Yash S Dayal, Cameron Laurie, Mohadese Ahmadzade, David Wynne, Mohammad Ghasemi-Rad

Faculty, Staff and Students Publications

Hepatic encephalopathy (HE) is a common complication following transjugular intrahepatic portosystemic shunt (TIPS) placement and is thought to result from reduced hepatic detoxification of neurotoxins. However, Zhuang et al in the World Journal of Radiology demonstrate that this understanding may be incomplete through exploration of the pathophysiology from a hemodynamic perspective. They found significant changes in cerebral blood flow (CBF) and spontaneous brain activity following TIPS. Initially, CBF increased in specific areas within the first month, followed by a return to baseline at three months. These CBF changes coincided with increased spontaneous brain activity that persisted in some areas, suggesting …

Folr1-Targeted Actinium-225-Based Alpha-Particle Therapy Eliminates Ovarian Cancer, Neetu Singh, Esther Need, Ayden Berndt, Matthew Goff, Lydia J. Wilson, Firas Mourtada, Feng Guo, Tara Mastren, Taslim Al-Hilal, Anil K. Sood, Amit Maity, Scott C. Miller, Satoshi Minoshima, Shreya Goel, Sixiang Shi

Department of Radiation Oncology Faculty Papers

Despite the advancement in therapies, ovarian cancer treatment is challenging because of poor prognosis and high relapse associated with acquired resistance. Emerging targeted alpha particles, particularly actinium-225 (225Ac), for treating refractory cancers have opened avenues for improved therapeutic options. Here, we describe a successful example of folate receptor 1 (FOLR1)–targeted 225Ac alpha-particle therapy for treatment of ovarian cancer. Longitudinal positron emission tomography imaging demonstrated high tumor-specific uptake of αFOLR1 (anti-FOLR1 antibody) in SKOV3 xenografts. FOLR1-targeted 225Ac demonstrated high therapeutic efficacy, achieving marked tumor regression, 80% survival, and 40% complete tumor elimination. The therapy resulted in tumor-specific double-stranded DNA damage, and …