Radiation Medicine Commons^™

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 …

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

House Staff Quality Improvement and Patient Safety Conference (2020-)

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.

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

House Staff Quality Improvement and Patient Safety Conference (2020-)

Research Objective

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

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

House Staff Quality Improvement and Patient Safety Conference (2020-)

• 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.

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

Dissertations & 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 …

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.

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 …

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 …

Dietary Alterations Modulate The Microrna 29/30 And Igf-1/Akt Signaling Axis In Breast Cancer Liver Metastasis., Anuradha A. Shastri, Anthony Saleh, Jason E. Savage, Tiziana Deangelis, Kevin Camphausen, Nicole L. Simone

Department of Radiation Oncology Faculty Papers

Background: Metastatic cancer is incurable and understanding the molecular underpinnings is crucial to improving survival for our patients. The IGF-1/Akt signaling pathway is often impaired in cancer leading to its progression and metastases. Diet modification is known to alter the IGF-1/Akt pathway and affect the expression of microRNA involved in tumor initiation, growth and metastases. Liver metastases are one of the most common type of metastases in breast and colon cancer. In the present study, we looked at the effect of diet modification on the expression of microRNA in normal liver and liver with breast cancer metastases using in vivo …

Design And Analysis Of A Novel Long-Distance Double Tendon-Sheath Transmission Device For Breast Intervention Robots Under Mri Field, Xiaohong Jia, Yongde Zhang, Jingang Jiang, Haiyan Du, Yan Yu

Department of Radiation Oncology Faculty Papers

Cancer represents a major threat to human health. Magnetic resonance imaging (MRI) provides superior performance to other imaging-based examination methods in the detection of tumors and offers distinct advantages in biopsy and seed implantation. However, because of the MRI environment, the material requirements for actuating devices for the medical robots used in MRI are incredibly demanding. This paper describes a novel double tendon-sheath transmission device for use in MRI applications. LeBus grooves are used in the original transmission wheels, thus enabling the system to realize long-distance and large-stroke transmission with improved accuracy. The friction model of the transmission system and …

Atrx Loss In Pediatric Glioma Results In Epigenetic Dysregulation Of G2/M Checkpoint Maintenance And Sensitivity To Atm Inhibition, Brendan Mullan, Tingting Qin, Ruby Siada, Carla Danussi, Jacqueline Brosnan-Cashman, Drew Pratt, Taylor Garcia, Viveka Nand Yadav, Xinyi Zhao, Meredith Morgan, Sriram Venneti, Alan Meeker, Alnawaz Rehemtulla, Pedro Lowenstein, Maria Castro, Carl Koschmann

Medical Student Research Symposium

ATRX is a histone chaperone protein recurrently mutated in pediatric glioma. The mechanism which mediates the proliferative advantage of ATRX loss in pediatric glioma remains unexplained. Recent data revealed a distinct pattern of DNA binding sites of the ATRX protein using ChIP-seq in mouse neuronal precursor cells (mNPCs). Using the ATRX peaks identified in p53^-/- mNPCs, we confirmed that ATRX binding sites were significantly enriched in gene promoters (p < 0.0001) and CpG islands (p < 0.0001) compared with random regions. Gene set enrichment (GSE) analysis identified that cell cycle and regulation of cell cycle were among the most significantly enriched gene sets (p=2.52e-16 and 1.61e-9, respectively). We found that ATRX loss resulted in dysfunction of G2/M checkpoint maintenance: (1) ATRX-deficient pediatric glioblastoma (GBM) cells exhibited a seven-fold increase in mitotic index at 16 hours after sub-lethal radiation, and (2) murine GBM cells with ATRX knockdown demonstrated impaired pChk1 signaling on western blot at multiple time points after radiation compared to controls (p=0.0187). Notably, the ATM signaling (pChk2) remained intact in those cells, suggesting a potential therapeutic target. ATRX-deficient mouse cells were uniquely sensitive to ATM inhibitors at 1 uM alongside 8 Gy radiation compared to controls with intact ATRX (AZD0156: p=0.0027 and AZD01390: p=0.0436). Mice intra-cranially implanted with ATRX-deficient GBM cells showed improved survival (n=10, p=0.0018) when treated with AZD0156 combined with radiation. Our findings suggest that ATRX loss in glioma results in unique sensitivity to ATM inhibition via epigenetic dysregulation of G2/M checkpoint maintenance.

The Pivotal Role Of Patient-Centred Approaches In Successful Outcome Of Evidence-Based High Quality Cancer Care, Ahmed Nadeem Abbasi

Department of Radiation Oncology

No abstract provided.

Development Of A Robust Treatment Delivery Framework For Stereotactic Body Radiotherapy (Sbrt) Of Synchronous Multiple Lung Lesions, Lana Catherine Critchfield

Theses and Dissertations--Radiation Medicine

Stereotactic body radiation therapy (SBRT) of lung tumors uses high doses of radiation to deliver high biological effective doses (BED) in very few fractions (1-5). With the use of highly conformal fields to cover the tumor without depositing large doses to non-cancerous structures, this technique has proven time and again to be successful at achieving high local control. However, frequently patients receiving SBRT are elderly with multiple medical comorbidities who may not tolerate long treatment times. Furthermore, many patients present with oligometastatic or multiple primary lung tumors. The success of SBRT on oligometastatic lung disease relies on physician experience with …