Medical Specialties Commons^™

Detection Of Progression Or Regression Of Breast Cancer By Circulating Tumor Dna (Ctdna), Ujjwal Karki, Bipin Ghimire, Emma Herrman, Siddhartha Yadav, Mohammad Muhsin Chisti

Conference Presentation Abstracts

Circulating tumor DNA (ctDNA) are short DNA sequences shed by tumor cells into the systemic circulation. Studies have shown potential utility of the test to predict relapse or recurrence following treatment in solid tumors, but sensitivity and specificity have varied widely, ranging from 19-100% and 80-100% respectively, in breast cancer specifically. Moreover, literature describing the utility of monitoring dynamic changes in ctDNA trends is limited. We aim to evaluate the correlation between ctDNA test, both single test as well as dynamic trends in value over time, with imaging findings.

Expansion Of The Detrusor Muscular Ring Surrounding The Bladder Neck On Mri: Moving Beyond The Prostate As An Etiology Of Lower Urinary Tract Symptoms Due To Benign Prostatic Hyperplasia, Kiran Nandalur, David Walker, Hong Ye, Sayf A. Al-Katib, Brian Seifman, David Gangwish, Abhay Dhaliwal, Connor Ervin, Kayla Dobies, Channing Sesoko, Sirisha Nandalur, Bernadette Zwaans, Jennifer Nguyen, Jason Hafron

Conference Presentation Abstracts

Purpose: The etiology of lower urinary tract symptoms secondary to benign prostatic hyperplasia (LUTS/BPH) remains uncertain. The purpose of our study was to quantitatively analyze pelvic anatomic characteristics on magnetic resonance imaging (MRI) to assess for independent factors for symptoms.
*Methods and Materials: This retrospective single-institution study evaluated treatment-naïve men who underwent prostate MRI within 3 months of International Prostate Symptom Score (IPSS) from June 2021 to February 2022. Factors measured on MRI included: detrusor muscular ring surrounding the bladder neck measured as area and alternatively diameter, central gland (CG) mean apparent diffusion coefficient (ADC), levator hiatus (LH) volume, intrapelvic …

Automating 4dct-Ventilation Imaging Generation Using Ai-Based Advanced Lung Contours, Yingxuan Chen, Sohrab Pahlavan, Paul Jacobs, Farnoush Forghani, Edward Castillo, Richard Castillo, Yevgeniy Vinogradskiy

Conference Presentation Abstracts

Purpose: Functional avoidance radiotherapy uses functional imaging to reduce pulmonary toxicity by designing radiotherapy plans that reduce doses to functional lung. A novel form of lung functional imaging applied for functional avoidance uses 4DCT imaging to calculating 4DCT-based lung ventilation (4DCT-ventilation). The process of generating 4DCT-ventilation images requires advanced lung segmentation (consisting of a standard lung with airway and vasculature removed) which is a manual and time-consuming process. The purpose of this work is to automate 4DCT-ventilation imaging generation using AI-based auto-segmentation techniques for advanced lung contouring.

Methods: 429 patients with 4DCT data from two institutions were used. Three methods …

End-To-End Commissioning & Treatment Plan Quality Assurance For Cranial Single-Isocenter Multi-Target (Simt) Radiosurgery, Cory Knill

Conference Presentation Abstracts

No abstract provided.

Trust-Ii: A Global Phase Ii Study For Taletrectinib In Ros1 Fusion-Positive Lung Cancer And Other Solid Tumors, Misako Nagasaka, Shunichi Sugawara, Chang-Min Choi, Tatsuro Okamoto, Noriko Yangitani, Kaname Nosaki, Toshiaki Takahashi, Yutaka Fujiwara, John Khoury, Jorge J. Nieva

Conference Presentation Abstracts

Background: Taletrectinib (AB-106/DS-6051b) is a next-generation, brain-penetrant, ROS1/ NTRK tyrosine kinase inhibitor (TKI) and has shown clinically meaningful effect and safety profile in ROS1+ Non-Small Cell Lung Cancer (NSCLC) patients in phase 1 studies (Fujiwara et al, Oncotarget 2018; 9(34): 23729-23737; Ou et al, JTO Clin Res Rep. 2020 Oct 21;2(1):100108). Taletrectinib has also demonstrated activity against ROS1 G2032R resistance mutation and CNS metastases in the ongoing phase 2 TRUST study (NCT04395677) in China. Also, taletrectinib has shown preliminary efficacy against NTRK positive solid tumors in an ongoing phase 2 study (NCT04617054). Methods: TRUST-II study (NCT04919811) is a phase 2, …

Merkle Cell Carcinoma While On Rituximab - Is It A Coincidence?, Bana Antonios, Emma Herrman, Mohammad Muhsin Chisti

Conference Presentation Abstracts

A 79-year old woman with history of relapsed Stage II, grade III follicular lymphoma was treated with four cycles of rituximab and bendamustine with an excellent response. She was subsequently placed on maintenance rituximab infusions every eight weeks. Six months later, she presented to the dermatology clinic with a newly raised erythematous papule on her left cheek. Excisional biopsy confirmed a diagnosis of Merkel cell carcinoma which was resected with wide margins. Merkel cell carcinoma (MCC) is a rare aggressive skin malignancy, with a dramatic increase in incidence in the past few decades. It grows and metastasizes rapidly and diagnosis …

Hepatoid Adenocarcinoma Of Lung: A Rare And Challenging Tumor, Bipin Ghimire, Ashbina Pokharel, Samiksha Pandey, Ujjwal Jung Karki, Can Wang, Michael Stender

Conference Presentation Abstracts

Hepatoid adenocarcinoma (HAC) is an extremely rare extra-hepatic malignant tumor having hepatic features on pathology. Stomach is the most common site, and hepatoid adenocarcinoma of lung (HAL) accounts for 2.3 – 5% of all HACs. Less than 100 cases of HAL have been reported worldwide since its concept was put forward in 1990. A 63-year-old female presented to the ED with back pain. Initial evaluation revealed anemia (hemoglobin 6.7), hypercalcemia (12.1 mg/dl), GFR 54 mL/min. X-ray thoracic spine and chest showed two vertebral compression deformities and lytic lesions on multiple ribs. Initially, multiple myeloma was considered likely but further evaluation …

Contralateral Control Rate With Unilateral Proton Beam Radiotherapy For Oropharyngeal Scc: A Multi-Institutional Prospective Study From The Proton Collaborative Group, Aleksander Vayntraub, Thomas Quinn, John Chang, Noah Kalman, Sanford Katz, James Urbanic, Arpi Thukral, Jason Molitoris, Craig Stevens, Rohan Deraniyagala

Conference Presentation Abstracts

Introduction: Select patients with oropharyngeal SCC are candidates for unilateral radiation therapy. We sought to investigate if ipsilateral targeting leads to increased contralateral recurrences. Methods: We queried the PCG database for patients treated with unilateral proton RT for head and neck SCC from 2015 – 2020 at 12 institutions. DICOMs were evaluated to ensure dose delivered matched a unilateral proton treatment plan. Demographic, clinical and pathological, toxicity and dosimetry information were compiled. Results: We found 43 cases treated with unilateral proton RT. 94% (n¼16) of recurrent cases received prior radiation. Oropharyngeal sites included tonsillar fossa (n¼32), and base of tongue …

Assessing The Interplay Effect Based On A Precise Machine-Specific Delivery Sequence And Time For Cyclotron Accelerator Proton Therapy System., Lewei Zhao, Gang Liu, Jiajian Sher, Andrew Lee, Di Yan, Rohan Deraniyagala, Craig Stevens, Xiaoqiang Li, Shikui Tang, Xuanfeng Ding

Conference Presentation Abstracts

Purpose: We proposed an experimental approach to build a precise machine-specific model for standard, volumetric, and layer repainting delivery based on a cyclotron accelerator system. Then, we assessed the interplay effect using a 4D mobile lung target phantom compared to a generic delivery sequence model from West German Proton Therapy Essen (WPE). Methods: The machine delivery log files, from an IBA ProteusPLUSt system, were retrospectively analyzed to quantitatively model energy layer switching time, spot switching time, and spot drill time for standard and volumetric repainting delivery. To quantitatively evaluate the interplay effect, a series of digital thoracic 4DCT image sets …

The First Modeling Of The Spot-Scanning Proton Arc(Sparc) Delivery Sequence And Investigating Its Efficiency Improvement, Xuanfeng Ding, Gang Liu, Lewei Zhao, Rohan Deraniyagala, Craig Stevens, Di Yan, Xiaoqiang Li

Conference Presentation Abstracts

Purpose: Introduce an experimental approach to model a precise prototype arc system and quantitatively assess its efficiency improvement in the routine proton clinical operation. Methods: The SPArc delivery sequence model(DSMSPArc) includes two kinds of parameters:(1) mechanical parameters. (2) irradiation parameters. Log files and an independent gantry inclinometer were used to derive the irradiation parameters through a series of test plans. The in-house DSMSPArc was established by fitting both mechanical and irradiation parameters. Eight SPArc plans from different disease sites were used to validate the model’s accuracy. To assess the treatment efficiency improvement, the DSMSPArc was used to simulate the SPArc …

A Quantitative Dose Pertubation Comparison Study Between Gold And Platinum Visicoil Fiducial Markers In Proton Beam Therapy, Xuanfeng Ding, Gang Liu, Weili Zheng, Jessica Vadas, Xiaoqiang Li, Lewei Zhao, An Qin, Daniel Krauss, Di Yan

Conference Presentation Abstracts

Purpose: To quantitatively investigate the dose perturbations difference between gold and platinum VISICOILTM fiducial markers in proton beam therapy Method: Gold and platinum VISICOILTM fiducial markers with two different dimensions were tested, including 0.35 & 0.5mm in diameter and 5mm in length. Total four kinds of markers. Gafchromic EBT2 was used to measure dose perturbations along the beam path in a ‘‘sandwich’’ setup (Figure 1). Dose perturbation was reported in each depth (0.3mm, 1.65mm, 3.00mm, 5.40mm, 7.80mm, 10.20mm, 12.60mm, 18.15mm). Relative proton stopping power relative to water were calculated through National Institute of Standards and Technology database and SRIM (version …

A Direct Machine-Specific Parameters Incorporated Spot-Scanning Proton Arc (Sparc) Algorithm, Gang Liu, Lewei Zhao, Di Yan, Xiaoqiang Li, Xuanfeng Ding

Conference Presentation Abstracts

Purpose: To address the challenges of generating a deliverable and efficient spot-scanning proton arc (SPArc) plan for a proton therapy system. We developed a novel SPArc optimization algorithm (SPArcDMSP) by directly incorporating machinespecific parameters such as mechanical constraints and delivery sequence. Method and Material: A SPArc delivery sequence model (DSMarc) was built based on the machine-specific parameters of the prototype arc delivery system IBA ProteusONEt. The SPArcDMSP resamples and adjusts each control point’s delivery speed based on the DSMarc calculation through the iterative approach (Fig1). Users could set the expected delivery time and gantry max acceleration as a mechanical constraint …

Detection Of Progression Or Regression Of Gynecologic Cancers By Circulating Tumor Dna (Ctdna), Bipin Ghimire, Ujjwal Karki, Emma Herrman, Mohammad Muhsin Chisti

Conference Presentation Abstracts

Objectives The use of post-operative circulating tumor DNA (ctDNA) to detect cancer recurrence has been reported in various studies but the literature describing variable changes in ctDNA is limited. The objective of this study is to describe the utility of single and serial ctDNA values in detecting the progression or regression of gynecological cancers.

Methods This is a retrospective observational study including nineteen patients, aged >=18 years who had the ctDNA test completed at hematology/oncology clinic of William Beaumont – Royal Oak and Troy Hospitals, Michigan, USA.

Results Among the nineteen patients, fifteen had breast, three had ovarian, and one …