Radiation Medicine Commons^™

Ms211: Obit For Bishop Hearn, Armin Weinberg

Works on Radiation Effects: 1990-2020

Obit for Bishop Hearn in Sept 9, 2020 Houston Chronicle, He was instrumental in asking Armin to help engage in the work supported by AIHA to compliment his Methodist interest in Kazakhstan. Without him the project would not have begun nor ended . Because of him TMH provided multiple years of support that complimented the AIHA funding and allow Armin to bring many other resources to their effort. A truly warm, respectful and supportive leader. See more at Armin Weinberg, PhD Papers and its finding aid.

Estimating Partial Body Ionizing Radiation Exposure By Automated Cytogenetic Biodosimetry, Peter Rogan

Biochemistry Publications

Purpose: Inhomogeneous exposures to ionizing radiation can be detected and quantified with the Dicentric Chromosome Assay (DCA) of metaphase cells. Complete automation of interpretation of the DCA for whole body irradiation has significantly improved throughput without compromising accuracy, however low levels of residual false positive dicentric chromosomes (DCs) have confounded its application for partial body exposure determination.

Materials and Methods: We describe a method of estimating and correcting for false positive DCs in digitally processed images of metaphase cells. Nearly all DCs detected in unirradiated calibration samples are introduced by digital image processing. DC frequencies of irradiated calibration …

Acute Toxicity And Local Response Using Three Fractions Of High Dose Rate (Hdr) Brachytherapy For Curative Treatment Of Carcinoma Cervix, Nasir Ali, Bilal Mazhar Qureshi, Ahmed Nadeem Abbasi, Asim Hafiz, Benazir Mir, Abdul Qadir Jangda

Department of Radiation Oncology

To determine the acute vaginal mucosal toxicity and clinical response of cervical cancer after definitive treatment with external beam radiotherapy (EBRT) and three fractions each of 8 Fray (Gy) high dose rate intracavitary brachytherapy (HDR-BT).
Study design: Descriptive study.
Place and duration: Radiation Oncology Section, Department of Oncology, The Aga Khan University Hospital, Karachi, Pakistan from January 2008 till December 2015.
Methodology: Protocol was formulated for carcinoma cervix to complete treatment in 7 weeks. Patients were treated with chemotherapy and pelvic EBRT to a total dose of 45 Gy/25 fractions, followed by three intracavitary HDR brachytherapy fractions of 8 Gy …

Modeling Anatomic Changes For Adaptive Radiotherapy In Locally Advanced Lung Cancer Patient Population, James Alexander Kavanaugh

LSU Doctoral Dissertations

Anatomic changes occurring mid-treatment for patients undergoing radiation therapy for locally advanced lung cancer can degrade the quality of the intended treatment plan. These changes include tumor regression, geometric misalignment, and lung density changes (atelectasis and pleural effusion), and are visible on the daily 3D cone beam CT (CBCT). To maintain the intended treatment quality, adaptive radiotherapy (ART) can be employed to modify the treatment plan to account for these anatomic changes. However, the evaluation on when to adapt is currently completed manually by the treating clinicians, resulting in a subjective and inconsistent application. To address these limitations, a series …

Dosimetric Differences Between Cesium-131 And Iodine-125 Brachytherapy For The Treatment Of Resected Brain Metastases, Menachem Yondorf, Shahdabul Faraz, Andrew Smith, Albert Sabbas, Bhupesh Parashar, Theodore Schwartz, Gabriella Wernicke

Department of Radiation Oncology Faculty Papers

Purpose: To compare treatment plans and evaluate dosimetric characteristics of permanent cesium-131 (131Cs) vs. iodine-125 (125I) implants used in brain brachytherapy. Material and methods: Twenty-four patients with 131Cs implants from a prospective phase I/II trial were re-planned with 125I implants. In order to evaluate the volume of brain tissue exposed to radiation therapy (RT), the dose volume histogram was generated for both radioisotopes. To evaluate the dosimetric differences of the two radioisotopes we compared homogeneity (HI) and conformity indices (CI), and dose covering 100% (D100), 90% (D90), 80% (D80), and 50% (D50) of the clinical target volume (CTV). Results: At …

Deep Learning Vs. Atlas-Based Models For Fast Auto-Segmentation Of The Masticatory Muscles On Head And Neck Ct Images, Wen Chen, Yimin Li, Brandon A. Dyer, Xue Feng, Shyam Rao, Stanley H. Benedict, Quan Chen, Yi Rong

Markey Cancer Center Faculty Publications

BACKGROUND: Impaired function of masticatory muscles will lead to trismus. Routine delineation of these muscles during planning may improve dose tracking and facilitate dose reduction resulting in decreased radiation-related trismus. This study aimed to compare a deep learning model with a commercial atlas-based model for fast auto-segmentation of the masticatory muscles on head and neck computed tomography (CT) images.

MATERIAL AND METHODS: Paired masseter (M), temporalis (T), medial and lateral pterygoid (MP, LP) muscles were manually segmented on 56 CT images. CT images were randomly divided into training (n = 27) and validation (n = 29) cohorts. Two …

A Novel And Clinically Useful Dynamic Conformal Arc (Dca)-Based Vmat Planning Technique For Lung Sbrt, Damodar Pokhrel, Justin Visak, Lana Sanford

Radiation Medicine Faculty Publications

PURPOSE: Volumetric modulated arc therapy (VMAT) is gaining popularity for stereotactic treatment of lung lesions for medically inoperable patients. Due to multiple beamlets in delivery of highly modulated VMAT plans, there are dose delivery uncertainties associated with small-field dosimetry error and interplay effects with small lesions. We describe and compare a clinically useful dynamic conformal arc (DCA)-based VMAT (d-VMAT) technique for lung SBRT using flattening filter free (FFF) beams to minimize these effects.

MATERIALS AND METHODS: Ten solitary early-stage I-II non-small-cell lung cancer (NSCLC) patients were treated with a single dose of 30 Gy using 3-6 non-coplanar VMAT arcs (clinical …

Brain Extraction On Mri Scans In Presence Of Diffuse Glioma: Multi-Institutional Performance Evaluation Of Deep Learning Methods And Robust Modality-Agnostic Training, Siddhesh Thakur, Jimit Doshi, Sarthak Pati, Saima Rathore, Chiharu Sako, Michel Bilello, Sung Min Ha, Gaurav Shukla, Adam Flanders, Aikaterini Kotrotsou, Mikhail Milchenko, Spencer Liem, Bs, Gregory S Alexander, Joseph Lombardo, Joshua D Palmer, Pamela Lamontagne, Arash Nazeri, Sanjay Talbar, Uday Kulkarni, Daniel Marcus, Rivka Colen, Christos Davatzikos, Guray Erus, Spyridon Bakas

Department of Radiation Oncology Faculty Papers

Brain extraction, or skull-stripping, is an essential pre-processing step in neuro-imaging that has a direct impact on the quality of all subsequent processing and analyses steps. It is also a key requirement in multi-institutional collaborations to comply with privacy-preserving regulations. Existing automated methods, including Deep Learning (DL) based methods that have obtained state-of-the-art results in recent years, have primarily targeted brain extraction without considering pathologically-affected brains. Accordingly, they perform sub-optimally when applied on magnetic resonance imaging (MRI) brain scans with apparent pathologies such as brain tumors. Furthermore, existing methods focus on using only T1-weighted MRI scans, even though multi-parametric MRI …

Log File-Based Dose Reconstruction To Moving Targets During Lung Stereotactic Body Radiation Therapy, Andrew S. Mcguffey

LSU Master's Theses

Purpose: To perform film-based verification of 4D dose reconstruction to moving targets during lung stereotactic body radiation therapy (SBRT).

Introduction: Current patient-specific quality assurance measures to test deliverability of plans with dynamic intensity modulation involve delivering beams to static measurement device and comparing the planned dose to measurement. However, motion-induced dose errors are not detected with static measurement. Previous studies have investigated combining machine log data with respiratory tracking to determine moving-target dose. By combining machine log data with anatomic and density information at each breathing phase from 4D-CT, intrafraction anatomical deformation due to respiration may be accounted for. However, …

Covid-19 Medical Papers Have Fewer Women First Authors Than Expected., Jens Peter Andersen, Mathias Wullum Nielsen, Nicole L Simone, Resa E Lewiss, Reshma Jagsi

Department of Radiation Oncology Faculty Papers

The COVID-19 pandemic has resulted in school closures and distancing requirements that have disrupted both work and family life for many. Concerns exist that these disruptions caused by the pandemic may not have influenced men and women researchers equally. Many medical journals have published papers on the pandemic, which were generated by researchers facing the challenges of these disruptions. Here we report the results of an analysis that compared the gender distribution of authors on 1893 medical papers related to the pandemic with that on papers published in the same journals in 2019, for papers with first authors and last …

Analytical Setup Margin For Spinal Sbrt Based On Measured Errors, Audrey Copeland

LSU Master's Theses

Purpose: No consensus currently exists in the radiotherapy community about the correct margin size to use for spinal SBRT. Margins have been proposed to account for various errors individually, but not with all errors combined to result in a single margin value. The purpose of this work was to determine a setup margin for spinal SBRT based on known and measurable errors during radiotherapy to achieve at least 90% coverage of the clinical target volume (CTV) with the prescription dose for at least 90% of patients and not exceed a 30 Gy point dose or 23 Gy to 10% of …

Successful Stereotactic Radiotherapy Of Meningiomas In A Patient With Cowden Syndrome: A Case Report, Christian Fernandez, Md, Corey Savard, Christopher J Farrell, Md, Wenyin Shi

Department of Radiation Oncology Faculty Papers

Cowden's Syndrome (CS) is a rare disease with increased risk for several carcinomas. Experimental studies and limited case reports have described the negative effects of radiotherapy. A 35-yearold woman presented with newly diagnosed CS and multiple meningiomas. She underwent subtotal resection of a right petroclival meningioma to relieve brainstem compression and received adjuvant fractionated stereotactic radiotherapy 50 Gy in 25 fractions with minimal side effects. Twenty months post-operatively the patient presented with neurological deficits from progression of additional meningiomas. Craniotomy was performed and gross total resection was achieved for all sites of disease. Imaging five months after surgery demonstrated progressive …

A Telehealth Clinical Workflow For Academic Radiation Oncology Programs During The Covid19 Pandemic, Gregor Manukian, Md, Phd, Christian Fernandez, Md, Paul Forrest, Adam Dicker, Md, Phd, Mark D. Hurwitz, Md

Health Equity and Quality Improvement (HEQI) Summit

• COVID19 has resulted in drastic measures to decrease exposure risks within healthcare systems, with cancer patients at increased risk of infection and death (Liang. Lancet Oncol. 2020).
• Telehealth is the delivery of medical care via interactive audio and/or video telecommunication services.
• Telehealth was previously used sparingly within the department of radiation oncology but has suddenly become the preferred method of contact.
• In order to maintain quality of care, patient satisfaction, resident learning, and reimbursement, a robust telehealth clinical workflow is critical.
• Our department engaged various stakeholder to quickly develop a clinical workflow.

Irradiation Of N95 Masks For Their Sterilization And Reuse During The Covid19 Pandemic, Tara Tyson, Phd, Alex Kubli, Ms, Matthew Mistro, Ms, Karen Mooney, Phd, Amy Harrison, Phd, Adam Dicker, Md, Phd

Health Equity and Quality Improvement (HEQI) Summit

Research Objective

We sought to investigate the feasibility of irradiation for N95 mask sterilization.

Avoid, Delay, Shorten. Results Of Radiation Oncology’S Covid19 Patient Exposure Risk Mitigation Guidelines, Alex Kubli, Ms, Lilya Babinski, Bs, Angelia Landers, Phd, Christian Fernandez, Md, Amy Harrison, Phd

Health Equity and Quality Improvement (HEQI) Summit

We implemented evidence-based COVID19 guidelines on 3/16/20 to minimize patient exposure risks by avoiding, delaying, and shortening patient treatments when possible.

We analyzed the effectiveness of our COVID guidelines by comparing the number of new patient starts and number of treatments before and after implementation.

Our department successfully decreased patient exposure risk by reducing new prescription starts, rates of longer treatment courses, and overall number of treatment encounters in an evidence-based approach.

The Effects Of Total Body Proton Irradiation On Mouse Myometrium, Lillith Bulawa

Undergraduate Honors Theses

The boundaries of human space exploration continue to expand with new technology and discoveries making it even more important to investigate the effects of space on biological systems. Although humans have explored space in small increments, reproductive studies must be conducted to determine if stable short- or long-term residences for humans can exist in space. This study explored the effects of whole-body proton radiation on uterine smooth muscle known as the myometrium. Two types of mice utilized in this study were C57BL/6 and B6.129S6Cybbtm1Din/J NOX2 knockout mice. C57BL/6 mice are standard laboratory mice that were used to represent the wildtype …

National Trends For Intra-Operative Radiation Therapy In Favorable, Early-Stage Breast Cancer: A Propensity Scoring Analysis Of The National Cancer Database, Mohamad Sebai, Muayad F. Almahariq, Joshua Dilworth, Patrick Karabon, Rachel Kalthoff, Sayee Kiran, Jayant Vaidya, Kyle J Feldmann, Nayan Dekhne

Articles

No abstract provided.

Development Of Fully Balanced Ssfp And Computer Vision Applications For Mri-Assisted Radiosurgery (Mars), Jeremiah Sanders

Dissertations and Theses (Open Access)

Prostate cancer is the second most common cancer in men and the second-leading cause of cancer death in men. Brachytherapy is a highly effective treatment option for prostate cancer, and is the most cost-effective initial treatment among all other therapeutic options for low to intermediate risk patients of prostate cancer. In low-dose-rate (LDR) brachytherapy, verifying the location of the radioactive seeds within the prostate and in relation to critical normal structures after seed implantation is essential to ensuring positive treatment outcomes.

One current gap in knowledge is how to simultaneously image the prostate, surrounding anatomy, and radioactive seeds within the …

Meeting Radiation Dosimetry Capacity Requirements Of Population-Scale Exposures By Geostatistical Sampling., Peter K Rogan, Eliseos J Mucaki, Ruipeng Lu, Ben C Shirley, Edward Waller, Joan H M Knoll

Biochemistry Publications

BACKGROUND: Accurate radiation dose estimates are critical for determining eligibility for therapies by timely triaging of exposed individuals after large-scale radiation events. However, the universal assessment of a large population subjected to a nuclear spill incident or detonation is not feasible. Even with high-throughput dosimetry analysis, test volumes far exceed the capacities of first responders to measure radiation exposures directly, or to acquire and process samples for follow-on biodosimetry testing.

AIM: To significantly reduce data acquisition and processing requirements for triaging of treatment-eligible exposures in population-scale radiation incidents.

METHODS: Physical radiation plumes modelled nuclear detonation scenarios of simulated exposures at …

Organ Preservation For Advanced Laryngeal Cancer: Experience With Concurrent Chemoradiation Therapy, Asif Ali Arain, Muhammad Shaheryar Ahmed Rajput, Shabbir Akhtar, Arsalan A. Rajput, Mohammad Adeel, Ahmad Hatem, Ahmed Nadeem Abbasi

Section of Otolaryngology, Head & Neck Surgery

Introduction: The larynx is a part of the upper respiratory tract that performs many essential functions including breathing, speaking, and swallowing. For this reason, the quality of life is significantly affected by laryngeal cancer and its treatment. Therefore, the focus of management for the last few decades has been on preserving the function of a larynx without compromising survival. This study was done with the purpose of reviewing our experience of organ preservation approach with concurrent chemoradiation therapy (CCRT) for locally advanced cancers of larynx.
Methods: A retrospective chart review was carried out for the data of pathology reports and …