Medical Specialties Commons^™

Development Of A Collision Model For Advanced Proton Treatment Planning And Delivery, Shupeng Chen, Lewei Zhao, Weili Zheng, An Qin, Rohan Deraniyagala, Xuanfeng Ding

Conference Presentation Abstracts

Purpose: A major barrier to implementing advanced proton therapy delivery techniques, such as proton arc/4pi delivery is the unknown characteristics of the collision zones, i.e., the combinations of couch and gantry angles that result in a mechanical collision between the gantry and couch or patient. This study aims to develop a collision model for the determination of patient-specific collision zones to enable safe and deliverable noncoplanar proton therapy treatment planning. Methods: The detailed geometric parameters of the treatment machine including the nozzle, the snout, and the size and the location of the range shifter were measured from an IBA Proteus …

Evaluation Of Variables Predicting Pulmonary Function Test (Pft) Changes For Lung Cancer Patients Treated On A Prospective 4dct-Ventilation Functional Avoidance Clinical Trial, Nader Ghassemi, Richard Castillo, Edward Castillo, Bernard L. Jones, Moyed Miften, Brian Kavanaugh, Maria Werner Werner-Wasik, Ryan Miller, Julie Barta, Inga Grills, Thomas Guerrero

Conference Presentation Abstracts

Purpose: Functional avoidance radiotherapy uses functional imaging to reduce pulmonary toxicity by designing radiotherapy plans that reduce doses to the functional lung. A novel form of lung functional imaging uses 4DCT imaging to calculate 4DCT-based lung ventilation (4DCT-ventilation) maps. A phase-II, multi-center, prospective study of 4DCT-ventilation functional avoidance was completed. Pre and post-treatment pulmonary function tests (PFTs) were acquired in order to quantitatively assess pulmonary function change. The purpose of this study is to evaluate which factors predict for PFT changes for patients treated with 4DCT-ventilation functional avoidance radiotherapy. Methods: 56 patients with locally advanced lung cancer receiving radiotherapy were …

Real-Time Tracking Diaphragm Motion On During-Treatment Kv Cone Beam Projection Images Using Resnet50, J Liang, Q Liu, E Porter, D Yan

Conference Presentation Abstracts

Purpose: Diaphragm manifested on Cone Beam projection image has been used as surrogate to monitor lung tumor position. We propose a deep learning method to detect diaphragm apex position of the ipsilateral lung in real-time on KV projections acquired during Lung SBRT delivery. Methods: 7 hypo-lung SBRT patients with right lower lobe tumor were selected in this retrospective study. The imaging projection angle ranges from about -270 to 112 degrees. The right lung diaphragm apex was manually labeled as ground-truth on KV projections acquired during-treatment sessions with 899±167 projections per session. The backbone of our machine learning model is 50 …

A Novel Ultra-High Dose Rate Proton Therapy Technology: Spot-Scanning Proton Arc Therapy Flash (Splash), Gang Liu, Lewei Zhao, Xiaoqiang Li, S Zhang, S Dai, X Lu, Xuanfeng Ding

Conference Presentation Abstracts

Purpose: The flash dose rate on the order of 40 Gy/s has the potential to spare normal tissue with iso-effective tumor growth delay. Meanwhile, the spot-scanning proton arc therapy(SPArc), demonstrated its superior dosimetric conformity and plan robustness compared to the conventional intensity modulated proton therapy(IMPT). To take the full advantage of flash dose rate and the high dose conformity, we introduce a novel optimization and delivery technique, SPArc FLASH (SPLASH). Methods: SPLASH framework was implemented in an open-source proton planning platform (matRad). It optimizes the spot moniter unit(MU) weighting and cyclotron beam current per spot simultaneously. More specifically, it simultaneously …

During-Treatment Imaging Feasibility For Intrafraction Stereotactic Spine Treatment Evaluations, M Liu, D Drake, D Lack, M Sigler, J Sliwinski, K Barton, D To, I Grills, J Liang

Conference Presentation Abstracts

Purpose: On Elekta linacs, cone-beam CTs (CBCT) can be acquired during VMAT delivery to monitor intrafraction motion during treatment. Stereotactic spine treatments can be lengthy, increasing patient motion likelihood during treatment. We evaluated during-treatment CBCT (DT-CBCT) feasibility to assess patient motion for stereotactic spine treatments in place of a mid-treatment CBCT. Methods: CBCTs from seven spine treatments were analyzed retrospectively. Various fractionation schemes were used (16-25Gy delivered in 1-5 fractions). All plans contained two VMAT arcs of 2209.5-13,332.4 MUs with treatment times of 7-58 minutes. Projections from pre-correction CBCTs were combined with post-correction CBCT to simulate patient motion (1cm, 2 …

A Team Learning Initiative In Undergraduate Medical Physics, B Loughery, J Mcbrady, M Joiner

Conference Presentation Abstracts

Purpose: To improve comprehension in traditionally difficult subjects for a senior-level undergraduate medical physics course, we designed and implemented a Team Learning technique. This work evaluates the translation of Team Learning to medical physics.  Methods: At the beginning of the term, students were sorted into 3 even teams (students/year = 14.5).  The class met twice weekly: a traditional lecture was taught first, and each team was assigned a specific 1/3 of the lecture material in which to specialize.  Each team was assigned to create a PowerPoint presentation on their material using outside references and without copying the original figures or …

Physics-Informed Machine Learning For Estimating Pulmonary Perfusion From Non-Contract 4dct, Y Liu, A Nowacki, R Castillo, Y Vinogradskiy, G Nair, C Stevens, E Castillo

Conference Presentation Abstracts

Purpose: Novel methods have been developed for functional avoidance that proposes to use 4DCT to derive lung ventilation and perfusion images. Previous methods for quantifying lung perfusion on non-contrast 4DCT rely either on HU-based physical models or black-box deep learning models. While deep learning typically achieves higher accuracies in image processing tasks, physical models provide a rationale for model predictions. The purpose of this study is to introduce a biophysics-informed machine learning method for estimating pulmonary perfusion from noncontrast 4DCT. Our approach is designed to combine the predictive power of neural networks with the interpretability of physical modeling, with the …

Quantifying Copd Disease Severity With Ct-Derived Perfusion Imaging, A Nowacki, G Nair, Y Liu, C J. Galban, C Stevens, E Castillo

Conference Presentation Abstracts

Purpose: CT-derived perfusion (CTP) is a novel image processing modality that quantifies pulmonary perfusion from non-contrast inhale/exhale CT image pairs. While existing imaging markers for COPD primarily depend on morphological features or HU thresholding, CTP provides a quantitative marker of blood flow and has been shown to identify disease progression prior to the appearance structural abnormalities. In this study, we assess the potential utility of CTP as a disease severity marker for COPD. Methods: CTP was computed from high-resolution inhale-exhale CT scans for 785 patients with a Global Initiative for Obstructive Lung Disease (GOLD) score ranging from 0 to 4 …

Per-Fraction Deviation In Logfile Parameters Reported In A Single Vmat Arc, M Snyder, D To, D Drake, J Liang, D Lack

Conference Presentation Abstracts

Purpose: Measurement-based QA identifies large deviations between planned and delivered dose, but subtle—yet clinically unacceptable—deviations can pass through the conventional QA process unnoticed. Incorporating logfilebased information into pre-treatment QA should result in more robust QA overall, provided such information is stable across the entire treatment course. We present here a case-study of logfile stability to investigate the potential of logfiles as useful adjuncts in the QA process. Methods: We analyzed logfiles from six fractions of a VMAT plan delivered on an Elekta Infinity linac with an Agility MLC. To simplify the analysis, we considered a single 52 control point VMAT …

A Novel Simultaneous Plan Quality And Beam Delivery Time Sparc Optimization Platform Using Primal Dual Active Set With Continuation (Pdasc), Lewei Zhao, J You, Gang Liu, X Lu, Xuanfeng Ding

Conference Presentation Abstracts

Purpose: Proton arc is a new treatment modality that delivers proton beams while continuously rotating the gantry. This study proposed a regularized l0-minimization primal dual active set with continuation (PDASC) algorithm for proton arc spot sparsity optimization to simultaneously optimize the plan quality and the beam delivery time (BDT). Methods: Based on the previously published beam delivery sequence model of IBA ProteusONE®, proton treatment delivery time is actually dominated by spot switching time (SSWT). SSWT is approximately linearly dependent on spot numbers. So we used a non-convex l0-norm to control the sparsity level of the regularized solution. The clinical objective …

Validation Of A Whole Genome Methylation Profiling Classifier For Central Nervous System Tumors, Lucas Santana-Santos, Kwok Ling Kam, David Dittman, Stephanie De Vito, Matthew Mccord, Pouya Jamshidi, Hailie Fowler, Xinkun Wang, Alan Aalsburg, Daniel Brat, Craig Horbinski, Lawrence Jennings

Conference Presentation Abstracts

Whole genome methylation profiling is proving to be an incredibly powerful tool to diagnose tumors that are otherwise difficult to classify by histopathology and sequencing. The reference library of tumor DNA methylation data, using a machine learning-based tumor classifier, was developed by the German Cancer Research Network (DKFZ), and is available publicly on a research basis. However, medical institutions desiring to implement that classifier for routine clinical care need to import, adapt, and validate the classifier internally. We did this for our own DNA methylation-based classifier of central nervous system (CNS) tumors, using the same training and validation datasets as …

Diffuse Alveolar Hemorrhage Due To Hydralazine-Induced Lupus, P Boshara, E Calvo-Ayala

Conference Presentation Abstracts

Introduction: Hydralazine is a known cause of drug-induced lupus. Rarely, it’s been reported to cause major organ-threatening complications, manifesting as kidney disease and CNS involvement. It’s also been associated with ANCA-positive vasculitis primarily involving the kidney, with uncommon pulmonary complications. We report a unique case of hydralazine-induced lupus presenting as diffuse alveolar hemorrhage (DAH) in the absence of renal disease or ANCA-positive vasculitis, which was successfully treated with systemic steroid monotherapy. Case description: The patient is an 86 year-old female with a history of chronic immune thrombocytopenia who presented to the hospital due to one week of dyspnea and hemoptysis. …

Comparison Of Aperture Complexity Between Vmat Plans Using Conventionally Flattened (Ff) And Flattening-Filter-Free (Fff) Beams, Q Liu, J Liang

Conference Presentation Abstracts

Purpose: VMAT plans with high amount of complex apertures could lead to less confidence in dose calculation accuracy due to machine modelling and dose algorithm limitations. It was hypothesized that VMAT plans generated with FFF beams would result in more complex aperture shapes due to the non-flattened beam profile. The purpose of this study was to test this hypothesis by assessing various plan complexity metrics. Methods: Target and organ-at-risk structures were created on an anthropomorphic phantom in various sites: lung, prostate, spine, pancreas, breast, rectum and HN. Hypo-fractioned VMAT plans were generated using Elekta Agility MLC in Pinnacle TPS. Both …

Validation And Implementation Of A Dedicated Spine Stereotactic Radiosurgery Treatment Planning System, C Knill, R Sandhu, B Loughery, L Lin, Z Seymour, P Chinnaiyan, T Quinn, M Almahariq, R Deraniyagala

Conference Presentation Abstracts

Purpose: A dedicated spine stereotactic radiosurgery optimization algorithm was commissioned for 6FFF Versa HD deliveries. Plan comparisons with the existing clinical optimization algorithm along with the dosimetric validation of the deliveries were investigated. Methods: Nine stereotactic spine patients, previously treated with Pinnacle generated plans, were re-optimized using Brainlab’s SRS spine planning Element. Three additional Elements plans were created for each patient: 1) initial optimization using a pencil beam calculation algorithm (PBC), 2) Monte Carlo (MC) recalculation of the PBC plan, and 3) re-optimization of the PBC plan using Monte Carlo. Patient dose from PBC plans was compared to MC recalculated …

Mri-Based Synthetic Ct Images Generated Using 3d Conditional Gan For Impt Treatment Planning, Shupeng Chen, An Qin, Rohan Deraniyagala, Xuanfeng Ding, Y Peng, Y Liu, C Zhao, X Deng

Conference Presentation Abstracts

Purpose: To develop an advanced deep convolutional neural network architecture to generate synthetic CT (SCT) images from MR images for intensity-modulated proton therapy (IMPT) treatment planning of head and neck cancer patients. Methods: T1-weighted MR images and paired CT (PCT) images were obtained from 189 nasopharyngeal cancer (NPC) patients under radiotherapy immobilization. Deformable image registration was performed between MR and PCT images for each patient to create an MR-CT image pair. Thirteen pairs were randomly chosen as independent test sets and the remaining 176 pairs (14 for validation and 162 for training) were used to build two conditional generative adversarial …

Impact Of Serum Igg Levels Against Sars-Cov-2 On Clinical Outcomes For Hopitalized Covid Patient, Bipin Ghimire, Bijaya Thapa, Nishant Aggarwal, Luai Madanat, Melinda Sager, Daniel O'Connor, Alexandra Halalau

Conference Presentation Abstracts

BACKGROUND: The SAR-CoV-2 pandemic continues to negatively impact the healthcare system globally with over 800,000 deaths in the United States and millions more worldwide. The cases are rising despite availability of vaccines. For most immunocompetent patients these vaccines will generate a humoral response and also a memory T-cell response. Few if any studies have reported data that measure anti-spike IgG titers and also correlate those titers with clinical outcomes in the instance of breakthrough infection.

METHODS: We conducted a pilot prospective observational clinical study enrolling 30 immunocompetent patients who were admitted with a positive SARS-CoV-2 PCR. Leftover blood from admission …

A Systematic Review And Meta-Analysis Of Diagnostic Accuracy Of Whole-Body 18f-Fdg Pet And 18f-Fdg Pet/Ct In Detecting Occult Malignancy In Patients With Idiopathic Inflammatory Myopathy, A Ali, R Alkilany, J Asif, B Basida, Z Al-Sagri, N Mahabadi, H Sarakbi

Conference Presentation Abstracts

Background Idiopathic inflammatory myopathies (IIMs) are chronic, systemic autoimmune diseases that can cause muscle inflammation, weakness, and skin manifestations. Several studies have confirmed the association between IIMs and malignancy in adult population with varied frequency (4-42%), highest in patients with dermatomyositis. Detecting occult malignancy is a diagnostic challenge involving cost- and time-consuming methods. The (18)F] fluorodeoxyglucose positron emission tomography ([(18)F] FDG-PET) role in this context has been studied in multiple studies.

Objectives The purpose of this study is to assess the diagnostic performance of whole-body 18F-FDG PET or 18F-FDG PET/CT for detection of occult malignancy in patients with IIMs.

Methods …

The Competitive Edge: Improving Absite Scores Through A Team-Based Approach, Sean Masters, Kathryn Howard, Darci Foote, Diane Studzinski, Rose E. Callahan, Felicia Ivascu, Begum Akay

Conference Presentation Abstracts

Introduction: A competitive team-based approach to encourage self-studying and didactic participation is a novel method of American Board of Surgery In-Training Examination (ABSITE) preparation. We aimed to determine if this method significantly improves residents’ percentile performances on the ABSITE. Methods: We reviewed ABSITE performance and preparation from general surgery residents for the last ten years. Percentile scores were compared before and after implementation of a purchased online question bank (TrueLearn LLC, Mooresville, NC), a team-based competition, and a virtual format of the team-based competition. Statistical analysis was performed with ANOVA Kruskal-Wallis and Mann Whitney tests where appropriate. Results: 378 ABSITE …

Aspnr Programing: Interesting Pediatric Neuroradiology Case Session (Sa-Cme): Seizures., A Krishnan

Conference Presentation Abstracts

No abstract provided.

Vertebral Artery Pathology: A Review Of Diagnosis And Angiographic Intervention, R Joshi, A Abbas, J Wilseck

Conference Presentation Abstracts

Purpose The vertebral arteries are a critical component of the spinal and posterior intracranial circulation. Their associated pathologies are wide ranging including traumatic and congenital causes. Given the profound impact on patient management and outcomes, a careful evaluation of the vertebral artery with a firm understanding of normal anatomy is required to properly rule out pathology. This educational exhibit will provide an overview of the normal anatomy of the vertebral arteries and a case-based review of a large spectrum of their pathologies, including traumatic, spontaneous, iatrogenic, and congenital. Utilization of various imaging modalities including, CTA, MRA, angiography, and ultrasound will …

A Rare Case Of Autoimmune Glial Fibrillary Acidic Protein Astrocytopathy, A Dearden, J Doty, A Krishnan, J Fellows

Conference Presentation Abstracts

Purpose This is a 69-year-old male who presented with cognitive decline, hypophonia, dyspraxia, course tremor, myoclonic jerks, and gait dysfunction, all developing over 3-4 weeks. Initial head CT and MRI brain without contrast were negative. EEG demonstrated diffuse slowing. CSF analysis revealed elevated protein and elevated white blood cells (lymphocyte predominant). Given neurological worsening, MRI brain and cervical spine with contrast were performed and unique findings were identified, detailed below. The CSF autoimmune panel returned positive for Glial Fibrillary Acidic Protein (GFAP). The patient was started on steroids with rapid clinical improvement. Materials and Methods MRI brain with contrast 2 …

Neuroimaging Spectrum Of Non-Compressive Non-Neoplastic Myelopathy, J Ghannam, A Dearden, R Joshi, A Wang, K Barry

Conference Presentation Abstracts

Purpose Non-compressive, non-neoplastic spinal cord lesions represent a broad range of disease processes and entities. Most commonly, spinal cord lesions demonstrate T2 signal abnormality on magnetic resonance imaging, a relatively nonspecific finding requiring a variety of differentiating factors to build an accurate differential diagnosis (1). Additionally, many disease entities have significant overlapping features on MRI, rendering it difficult to separate diagnoses and guide management (2). The combination of signal characteristics on MRI, timing of clinical presentation, degree of cord expansion, and contrast enhancement patterns can provide improved differentiation between disease entities. The purpose of this exhibit is to educate the …

Benign And Malignant Cervical Lymphadenopathy: A Practical Imaging Approach To The Diagnosis Of Common And Uncommon Conditions, A Dhaliwal, J Sharma, S Noujaim

Conference Presentation Abstracts

Purpose Generally, cervical lymphadenopathy is a benign, self-limited, and reactive process that is frequently encountered, especially in the pediatric population. However, when present in the setting of a neoplastic process, cervical lymphadenopathy is an important prognostic factor that can alter patient management. Determining the etiology of cervical lymphadenopathy is as essential as its detection. Etiologies include infection, granulomatous disease, malignancy, autoimmune disorders, iatrogenic causes, and miscellaneous or unusual conditions. Careful attention to clinical history and laboratory findings and the use of appropriate radiological imaging is crucial to obtaining the correct diagnosis. A variety of cases, including benign and malignant processes, …

Neuroimaging Spectrum Of Compressive Non-Neoplastic Myelopathy, A Dearden, J Ghannam, A Wang, A Krishnan

Conference Presentation Abstracts

Purpose Compressive non-neoplastic spinal cord lesions represent a broad spectrum of neurologic disease processes contributing to back pain and neuropathy, including traumatic, inflammatory/infectious, degenerative, and metastatic etiologies. Compressive cord lesions are optimally evaluated with high-field strength magnet MRI with and without contrast. Differential diagnoses for cord lesions are inherently broad due to the nonspecific nature of increased intramedullary signal on T2-weighted images seen with many cord pathologies. However, differentiating features such as degree of cord expansion, enhancement characteristics, and extramedullary findings can provide additional information to refine the differential diagnosis. In this exhibit, we present representative cases of compressive non-neoplastic …

The Onus On The Conus: A Neuroimaging Spectrum Of Conus Medullaris Pathologies, A Dearden, J Ghannam, A Wang, A Krishnan

Conference Presentation Abstracts

Purpose The conus medullaris is the tapered, cone-shaped end of the distal thoracic spinal cord, normally terminating near the L1-2 intervertebral disc space. As a junction between the cord and the cauda equina nerve roots, the conus can present with common cord pathologies in atypical presentations, as well as present with unique, complex pathologies found nowhere else in the cord. The conus is optimally evaluated with MRI of the lumbar spine before and after the administration of contrast medium. Accurate diagnosis of lesions within the conus is complicated by the nonspecific nature of increased intramedullary signal on T2-weighted MRI imaging, …

Spontaneous Aneurysmal Subdural Hemorrhage: A Rare Entity, M Rizk, A Khan, J Ghannam, M Waheed

Conference Presentation Abstracts

Purpose 36-year-old female who presented to our emergency department for worsening headache and new onset left sided diplopia. Physical exam confirmed a left 3rd nerve palsy. A CT of the head was obtained which showed a subdural hemorrhage which ultimately resulted in coil embolization of a ruptured aneurysm. The patient tolerated the procedure well and was closely followed for vasospasm development with routine transcranial ultrasounds which were negative. Patient remained stable and reported resolution of her headache symptoms on discharge. However, she continued to have a left 3rd nerve palsy. Materials and Methods CT of the head was obtained which …

Let Them Play: A Prospective Study Of Postoperative Activity Restrictions In Children, Rachel Harvey, Diane Studzinsk, Angela England, Robert Morden, Nathan M. Novotny, Anthony Stallion, Begum Akay

Conference Presentation Abstracts

No abstract provided.

Pituitary Metastasis Of Non-Small Cell Lung Cancer, Faris Alkhouri, Joseph Salib, Jack Artinian

Conference Presentation Abstracts

Lung cancer is the most commonly diagnosed cancer worldwide. Metastasis to other organs is also common. Of these, approximately 25% involve metastasis to the brain. In the brain, however, it is known that only 1% of brain metastasis involve the pituitary gland. In this report, we present a 70-year-old woman that was diagnosed with Non-Small Cell Lung Cancer (NSCLC) a year ago presenting with metastasis to the pituitary. A 70-year-old woman with past medical history of longstanding tobacco abuse, COPD, hypertension, and lung cancer (NSCLC stage IB in the upper right lobe diagnosed 1 year ago) presented to the emergency …

A Case Of Acute Unilateral Adrenal Hemorrhage Associated With Metastatic Lung Adenocarcinoma, Batoul Nasser, Ramona Berghea

Conference Presentation Abstracts

The most common cancer that metastasizes to the adrenal glands is lung cancer. Adrenal hemorrhage due to metastasis of lung cancer is extremely rare and associated with unilateral adrenal hemorrhage, while bilateral adrenal hemorrhages are typically associated with cardiovascular diseases and systemic anticoagulant therapy. Our 55-year-old male with a past medical history significant for metastatic lung adenocarcinoma and coronary artery disease (CAD) presented with acute right upper quadrant abdominal and flank pain. On presentation, patient was in distress, with fatigue, weakness, pain with deep inspiration, nausea, and vomiting. Patient also had anemia (hemoglobin 11.2). A CTA of the abdomen and …

Cannabis And Acute Coronary Syndrome: A Case Report Exploring Potential Links, Fawaz Habba

Conference Presentation Abstracts

No abstract provided.