Radiation Medicine Commons^™

In Vitro Α/Β Ratio Variations In Cervical Cancer, With Consequent Effects On Equivalent Dose In 2 Gy Fraction In High-Dose-Rate Brachytherapy, Cameron Thayer-Freeman, Brien Washington, Denise Fabian, Dennis C. Cheek, William St. Clair, Mark E. Bernard, Wei Luo

Radiation Medicine Faculty Publications

Purpose: To determine the distributions of published α/β values measured in vitro and the resulting uncertainties in the equivalent dose in 2 Gy fractions (EQD ₂ ) when applied to high-dose-rate brachytherapy (HDR-BT) for cervical cancer.

Methods and Materials: An analysis of 98 published α/β values from 31 papers was conducted, spanning 23 cervical cancer cell lines. Values were further divided into squamous cell carcinoma and adenocarcinoma histologies. Probability distributions were fit to histograms using the bootstrapped Kolmogorov-Smirnov goodness-of-fit test. Both average and most probable α/β values for cervical cancer were determined. The probability distributions were then applied to three …

Development And Clinical Validation Of Automated Same-Day Stereotactic Treatment Procedures For Multiple Brain Metastases And Recurrent Head And Neck Cancers, Shane Mccarthy

Theses and Dissertations--Radiation Medicine

As technology advances, more and more cancer patients are benefiting from the use of stereotactic radiosurgery and radiotherapy (SRS/SRT) to treat their disease. One such technology, Varian’s HyperArc high-definition radiosurgery module, a tool to help facilitate the treatment of brain metastases on a medical linear accelerator (LINAC), has been demonstrated to achieve comparable low dose spillage and target conformity compared to the current gold standard for intracranial malignancies, the Elekta Gamma Knife. Furthermore, due to HyperArc’s single-isocenter multiple lesion approach, the treatment can be delivered in a significantly shorter amount of time. Unfortunately, the manual process of creating these stereotactic …

A Two-Hit Model Of Executive Dysfunction: Simulated Galactic Cosmic Radiation Primes Latent Deficits Revealed By Sleep Fragmentation, Richard A. Britten, Ella N. Tamgue, Paola Arriaga Alvarado, Arriyam S. Fesshaye, Larry D. Sanford

Department Radiation Oncology & Biophysics Faculty Publications

Future Artemis-class missions to Mars will expose astronauts to prolonged space radiation (SR), sleep disruption, and operational demands requiring greater autonomy, placing decision making and executive function at heightened risk. Both SR and sleep fragmentation (SF) independently impair cognition, yet their combined effects remain poorly understood. Using the Associative Recognition Memory and Interference (ARMIT) task, we assessed cognitive performance in male rats exposed to 10 cGy of Galactic Cosmic Ray simulation (GCRsim), SF, or both. Under well-rested conditions, GCRsim-exposed rats exhibited overt deficits in the C.1.2 stage, performing at chance when reinforcement contingencies shifted, consistent with impaired cognitive flexibility. In …

Feasibility And Impact Of Knowledge-Based Automated Radiotherapy Treatment Planning In Low- And Middle-Income Countries, Awusi Kavuma, Solomon Kibudde, Yao Hao, Baozhou Sun

Faculty, Staff and Students Publications

Background and purpose: A high-quality treatment planning process is crucial in advanced radiotherapy techniques to ensure adequate dose to the target volume (TV) and sparing of organs at risk (OARs). This process often requires intensive labor, creating barriers for deployment in low- and middle-income countries (LMICs). We aimed to establish the feasibility of implementing knowledge-based auto-planning to facilitate clinical efficiency and increase patient throughput in an LMIC.

Materials and methods: We evaluated 60 randomly selected VMAT manual plans (VMPs), including 10 for each of the following sites: head and neck, oesophagus, breast, prostate, cervical, and rectal cancers. Using the same …

Percutaneous Stenting As Treatment For Chylothorax From Superior Vena Cava Syndrome: A Case Report, Arta Kasaeian, Taylor Hoffman, Mohammad Ghasemi Rad, David Wynne, David Léon

Faculty, Staff and Students Publications

Superior vena cava syndrome is a condition that results from obstruction of the superior vena cava, the etiology of which can be benign or malignant. The impaired venous return can cause facial and upper extremity swelling, dyspnea, and neurologic symptoms. Chylothorax is a rare complication of superior vena cava syndrome. We report a case of a 69-year-old male with end-stage renal disease, who developed both a chylothorax and a contralateral simple pleural effusion secondary to superior vena cava syndrome. He was successfully treated with percutaneous endovascular stenting.

A Fast Framework For Generating Radioactive Mixture Spectra And Its Application To Remote High-Performance Mixture Identification, Chiman Kwan, Bulent Ayhan, Adam Stavola, Kazi Aminul Islam, Hongfang Zhang, Jiang Li

Electrical & Computer Engineering Faculty Publications

Remote detection of radioactive materials in mixtures using handheld or portal detectors remains a challenge because of factors such as low concentration, environmental interference, sensor noise, and other complications. This work introduces a fast framework for generating realistic mixture spectra. Moreover, we present mixture isotope identification using data generated by the fast framework. Researchers have examined a range of conventional and recent algorithms within the fields of machine learning and deep learning. An application to uranium enrichment-level prediction has been included. Extensive simulation experiments validated the efficacy of the proposed framework.

Three-Dimensional Deep Learning Normal Tissue Complication Probability Model To Predict Late Xerostomia In Patients With Head And Neck Cancer, Hung Chu, Suzanne P M De Vette, Hendrike Neh, Nanna M Sijtsema, Roel J H M Steenbakkers, Amy Moreno, Johannes A Langendijk, Peter M A Van Ooijen, Clifton D Fuller, Lisanne V Van Dijk

Faculty, Staff and Student Publications

Purpose: Conventional normal tissue complication probability (NTCP) models for patients with head and neck cancer are typically based on single-value variables, which, for radiation-induced xerostomia, are baseline xerostomia and mean salivary gland doses. This study aimed to improve the prediction of late xerostomia by using 3-dimensional information from radiation dose distributions, computed tomography imaging, organ-at-risk segmentations, and clinical variables with deep learning (DL).

Methods and materials: An international cohort of 1208 patients with head and neck cancer from 2 institutes was used to train and twice validate DL models (deep convolutional neural network, EfficientNet-v2, and ResNet) with 3-dimensional dose distribution, …

Lyrical Stillness, Madhav Patel

HCA Healthcare Journal of Medicine

“Lyrical Stillness” is a poem I wrote during my radiation oncology rotation, during which I was provided the opportunity to learn more about multidisciplinary cancer care while delving deeper into radiotherapy. Cancer can be an overwhelming disease process physically, psychologically, and emotionally. Patients undergoing treatment often experience stress and anxiety with the uncertainty of their prognoses. In this poem, I describe a patient receiving radiation therapy whom I enjoyed speaking to about his favorite hobby: bird watching. During his subsequent radiation treatment sessions, I decided to play a CD of mockingbirds singing in a tropical forest, in the hopes it …

Analysis Of Impulsive Differential Equation Models Of Cell Populations Undergoing Radiation Therapy, Abigail D'Ovidio Long

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Radiation therapy is a mode of treatment which is implemented for approximately 50% of cancer patients. Treatment needs to be able to kill cancer cells, but also do minimal damage to surrounding healthy tissue. We propose two main impulsive differential equation models of radiation therapy to capture the periodic nature of the treatment. These models build off of previous studies using clinical data to ensure biological relevance. The first model incorporates only cancer cell populations, and we provide parameter relationships which theoretically ensure treatment outcomes of cancer eradication, cancer approaching a carrying capacity, and cancer approaching a periodic solution. We …

Novel Cuprotosis-Related Gene Signature: A Prognostic Indicator And Regulator Of The Glioma Immune Microenvironment, Dongming Gao, Youyuan Bao, Wenyin Shi, Lei Li, Liang Gao

Department of Radiation Oncology Faculty Papers

Background: Glioma is a primary malignant brain tumor with a poor prognosis. Glioma-related biomarkers need to be identified to enable the personalized treatment of and predict the prognosis of glioma patients. Cuproptosis is an unusual mechanism of cell death, and is closely associated with disease progression and the immune-microenvironment of the tumor. However, the function of cuproptosis in glioma is still unclear, therefore the aim of this study was to investigate the role of cuproptosis-related genes in gliomas.

Methods: We examined the relationship between cuproptosis and glioma using the clinical and expression data of glioma tumors from The Cancer Genome …

Isolation, Discrimination, And Feeling “Constant Guilt”: A Mixed-Methods Analysis Of Female Physicians’ Experience With Fertility, Family Planning, And Oncology Careers, Sarah Marion, Shraddha M Dalwadi, Aleksandra Kuczmarska-Haas, Erin F Gillespie, Michelle S Ludwig, Emma B Holliday, Bridgette Thom, Fumiko Chino, Anna Lee

Faculty, Staff and Students Publications

Introduction: Family planning among female physicians is harmed by high risks of infertility, workload burden, poor family leave policies, and gender discrimination. Many women report feeling unsupported in the workplace, despite national policies to protect against unfair treatment.

Methods: This secondary analysis applied a modified version of the rigorous and accelerated data reduction technique to conduct a thematic analysis of comments to an open-ended prompt. Comments were coded by multiple trained researchers then grouped and merged into illustrative themes via qualitative techniques.

Results: Of 1004 responses to the quantitative survey, 162 physicians completed the open-ended prompt. Initial codes (n = …

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,

Conference Report: Review Of Clinical Implementation Of Advanced Quantitative Imaging Techniques For Personalized Radiotherapy, Yevgeniy Vinogradskiy, Houda Bahig, Nicholas Bucknell, Jeffrey Buchsbaum, Hui-Kuo George Shu

Department of Radiation Oncology Faculty Papers

The topic of quantitative imaging in radiation therapy was presented as a "Masterclass" at the 2023 annual meeting of the American Society of Radiation Oncology (ASTRO). Dual-energy computed tomography (CT) and single-positron computed tomography were reviewed in detail as the first portion of the meeting session, with data showing utility in many aspects of radiation oncology including treatment planning and dose response. Positron emission tomography/CT scans evaluating the functional volume of lung tissue so as to provide optimal avoidance of healthy lungs were presented second. Advanced brain imaging was then discussed in the context of different forms of magnetic resonance …

Validation Of An Artificial Intelligence-Based Prognostic Biomarker In Patients With Oligometastatic Castration-Sensitive Prostate Cancer, Jarey H. Wang, Matthew P. Deek, Adrianna A. Mendes, Yang Song, Amol Shetty, Soha Bazyar, Kim Van Der Eecken, Emmalyn Chen, Timothy N. Showalter, Trevor J. Royce, Tamara Todorovic, Huei-Chung Huang, Scott A. Houck, Rikiya Yamashita, Ana P. Kiess, Daniel Y. Song, Tamara Lotan, Theodore Deweese, Luigi Marchionni, Lei Ren, Amit Sawant, Nicole L. Simone, Alejandro Berlin, Cem Onal, Andre Esteva, Felix Y. Feng, Phuoc T. Tran, Philip Sutera, Piet Ost

Department of Radiation Oncology Faculty Papers

BACKGROUND: There is a need for clinically actionable prognostic and predictive tools to guide the management of oligometastatic castration-sensitive prostate cancer (omCSPC).

METHODS: This is a multicenter retrospective study to assess the prognostic and predictive performance of a multimodal artificial intelligence biomarker (MMAI; the ArteraAI Prostate Test) in men with omCSPC (n = 222). The cohort also included 51 patients from the STOMP and ORIOLE phase 2 clinical trials which randomized patients to observation versus metastasis-directed therapy (MDT). MMAI scores were computed from digitized histopathology slides and clinical variables. Overall survival (OS) and time to castration-resistant prostate cancer (TTCRPC) were …

Durable Local Control With Hypofractionated Radiation Therapy For Unresectable Or Metastatic Melanoma, Sydney A Keatts, Aya F Salem, David M Swanson, Ahsan S Farooqi, Andrew J Bishop, Rodabe N Amaria, Jennifer L Mcquade, Isabella C Glitza Oliva, Adi Diab, Roi Weiser, Sarah B Fisher, Ryan P Goepfert, Merrick I Ross, B Ashleigh Guadagnolo, Devarati Mitra

Faculty, Staff and Student Publications

BACKGROUND AND PURPOSE: As patients with advanced melanoma live longer in the context of systemic therapy advancements, better strategies for durable control of bulky tumors are needed. In this study, we evaluated if dose-escalated hypofractionated radiation therapy (HFRT) can provide durable local control and improve tumor-associated symptoms in patients with unresectable or bulky metastatic melanoma for whom stereotactic ablative radiotherapy (RT) approaches are not feasible due to tumor size or location.

MATERIALS AND METHODS: We retrospectively reviewed 49 patients with unresectable or bulky metastatic melanoma who were treated to a total of 53 tumor targets with 12-17 fractions HFRT at …

Personalized Brachytherapy: Applications And Future Directions, Piyush Pathak, Justin J Thomas, Arjit Baghwala, Chengfeng Li, Bin S Teh, Edward B Butler, Andrew M Farach

Faculty, Staff and Students Publications

Brachytherapy offers a highly conformal and adaptive approach to radiation therapy for various oncologic conditions. This review explores the rationale, applications, technological advances, and future directions of personalized brachytherapy. Integration of advanced imaging techniques, 3D-printed applicators, and artificial intelligence are rapidly enhancing brachytherapy delivery and efficiency, while genomic tests and molecular biomarkers are refining patient and dose selection. Emerging research on combining brachytherapy with immunotherapy offers unique synergistic potential, and technologies such as intensity-modulated and shielded brachytherapy applicators present novel opportunities to further optimize dose distributions. Despite these promising advances, the field faces challenges including a need to train more …

Atr Inhibition Radiosensitizes Cells Through Augmented Dna Damage And G2 Cell Cycle Arrest Abrogation, Scott J Bright, Mandira Manandhar, David B Flint, Rishab Kolachina, Mariam Ben Kacem, David Kj Martinus, Broderick X Turner, Ilsa Qureshi, Conor H Mcfadden, Poliana C Marinello, Simona F Shaitelman, Gabriel O Sawakuchi

Faculty, Staff and Student Publications

Ataxia telangiectasia and Rad3-related protein (ATR) is a key DNA damage response protein that facilitates DNA damage repair and regulates cell cycle progression. As such, ATR is an important component of the cellular response to radiation, particularly in cancer cells, which show altered DNA damage response and aberrant cell cycle checkpoints. Therefore, ATR's pharmacological inhibition could be an effective radiosensitization strategy to improve radiotherapy. We assessed the ability of an ATR inhibitor, AZD6738, to sensitize cancer cell lines of various histologic types to photon and proton radiotherapy. We found that radiosensitization took place through persistent DNA damage and abrogated G2 …

Source Model Parameters For Beam Commissioning Of Scanning Proton Therapy Treatment Planning System: Multi-Institutional Survey And Analysis, Chih-Wei Chang, Liyong Lin, Lei Dong, Heng Li, Jan Po Schuemann, Jiajian Shen, Xuanfeng Ding

Conference Presentation Abstracts

Purpose: To create a beamline-specific repository of source model parameters and beam commissioning data for scanning proton therapy (PT) treatment planning system (TPS).

Methods: We surveyed 28 PT centers, collecting beam commissioning source model parameters of diverse beamlines from different vendors: Hitachi, IBA, Varian, Mevion. Parameters included (i) beam meterset calibration in protons per MU, (ii) in-air spot size at isocenter in terms of standard deviation in x- (crossline, σ_x) and y- (inline, σ_y) directions, (iii) in-air angular spread at isocenter in x-direction (θ_x) and y-direction (θ_y). We plotted each parameter as …

Tools And Recommendations For Commissioning And Quality Assurance Of Deformable Image Registration In Radiotherapy, Lando S Bosma, Mohammad Hussein, Michael G Jameson, Soban Asghar, Kristy K Brock, Jamie R Mcclelland, Sara Poeta, Johnson Yuen, Cornel Zachiu, Adam U Yeo

Faculty, Staff and Student Publications

Multiple tools are available for commissioning and quality assurance of deformable image registration (DIR), each with their own advantages and disadvantages in the context of radiotherapy. The selection of appropriate tools should depend on the DIR application with its corresponding available input, desired output, and time requirement. Discussions were hosted by the ESTRO Physics Workshop 2021 on Commissioning and Quality Assurance for DIR in Radiotherapy. A consensus was reached on what requirements are needed for commissioning and quality assurance for different applications, and what combination of tools is associated with this. For commissioning, we recommend the target registration error of …

S6k1 Controls Dna Damage Signaling Modulated By The Mrn Complex To Induce Radioresistance In Lung Cancer, Ali Calderon-Aparicio, Jun He, Nicole L. Simone

Department of Radiation Oncology Faculty Papers

Radiation is a mainstay of lung cancer treatment; however, resistance frequently develops. Identifying novel therapeutic targets to increase radiation sensitivity is crucial. S6K1 is a serine/threonine kinase known to regulate protein translation which is associated with radioresistance, but the mechanisms involved are unknown. We proposed to determine whether S6K1 promotes radioresistance by regulating DNA repair in lung cancer. Colony formation, protein expression and proliferation were assessed. S6K1 was modulated pharmacologically by either PF-4708671 or genetically by Crispr-Cas9. Higher radioresistance levels in lung cancer cells were associated with lower phosphoactivation of MRN complex members, a key activator of radiation-induced DNA repair …