Radiation Medicine Commons^™

First Quantitative Investigation On The Dosimetric Perturbation From Dental Hardware In Spot-Scanning Proton Arc (Sparc®) Therapy And Planning Strategies In Head Neck Cancer Patient Population, Evan Harbert

Masters Projects

Purpose

There has been a tremendous interest in applying Spot-scanning Proton Arc (SPArc^®) to benefit head and neck cancer (HNC) patient population. However, the dental hardware materials effects on the beam distribution are not well understood, and placing spots through the dental hardware may cause an unnecessary degradation of target coverage if the material components differ from the nominal plan. The purpose of this study is to provide a quantitative dose perturbation analysis of the uncertainties caused by dental hardware and introduce a SPArc^® planning strategy to mitigate such impacts.

Methods and Materials

A published in-house developed …

Mechanistic Insights Into The Flash Effect: The Role Of Oxygen And Radiation Chemistry In Ultra-High Dose Rate Radiation Therapy, Jacob Pierce Sunnerberg

Dartmouth College Ph.D Dissertations

The development of new cancer therapies focuses on widening the therapeutic ratio between tumor control and normal tissue toxicity. Over the last decade, ultra-high dose rate (UHDR) radiation therapy, commonly known as FLASH radiotherapy (FLASH-RT), has shown promising potential to reduce normal tissue toxicity while maintaining tumor control. However, the underlying mechanisms of the FLASH effect remain poorly understood. This thesis explores the radiation-chemical basis of FLASH-RT, focusing on the role of oxygen and reactive oxygen species in modulating biological outcomes.

A comprehensive set of in vitro studies demonstrated that UHDR delivery significantly alters radiation chemistry compared to conventional dose …

Cone Beam Ct Dose Optimisation: A Review And Expert Consensus By The 2022 Estro Physics Workshop Igrt Working Group, Lydia J. Wilson, Andria Hadjipanteli, Daniella E. Østergaard, Evelien Bogaert, Kirstie F. Brown, Rianne Dejong, James Earley, Magali Edouard, Marina Khan, Josh Lindsay, Jessica Van Der Himst, George X. Ding, Tim Wood, Marianne C. Aznar, Nuria Jornet, Georgios Ntentas

Department of Radiation Oncology Faculty Papers

Image guided radiotherapy (IGRT) using kilovoltage cone-beam CT (CBCT) has become an indispensable tool to ensure the geometric accuracy of radiotherapy treatment delivery. Although significant technical advances have been made in reducing imaging dose, the repeated imaging procedures can still accumulate significant dose to healthy tissues. Despite the widespread use, we still lack clear guidance for optimisation and widely accepted frameworks for evaluating the quality and suitability of CBCT imaging protocols. To address this gap, the 2022 European Society for Radiotherapy and Oncology (ESTRO) Physics Workshop focused on image-quality and imaging-dose optimisation for IGRT using CBCT. This publication represents a …

A Semiclassical Model Of The Immediate Temperature Distribution Surrounding The Track Of Heavy Ions With Therapeutic Energies, Martin Rädler, Niayesh Afshordi, Reza Taleei, Katia Parodi, Ramin Abolfath, Julie Lascaud

Department of Radiation Oncology Faculty Papers

Objective. Spikes of high temperature and pressure are created in the vicinity of heavy ions, especially at the Bragg peak. The expected subsequent thermoacoustic effects are however not well understood. In particular, the distribution of the densely packed primary interactions has not been considered in molecular dynamics (MDs) simulations or shock wave solutions. In this work, we derive a dedicated model to describe the primary interactions and their radial distribution, applicable to the modeling of acoustic and thermodynamic effects at the nanoscale. Approach. Starting from first principles, we assemble a semiclassical model of the energy loss of the primary heavy …

Decoding Resistance To Immune Checkpoint Inhibitors In Non-Small Cell Lung Cancer: A Comprehensive Analysis Of Plasma Proteomics And Therapeutic Implications, Michal Harel, Nili Dahan, Coren Lahav, Eyal Jacob, Yehonatan Elon, Igor Puzanov, Ronan J. Kelly, Yuval Shaked, Raya Leibowitz, David P. Carbone, David R. Gandara, Adam P. Dicker

Department of Radiation Oncology Faculty Papers

BACKGROUND: Immune checkpoint inhibitors (ICIs) have shown substantial benefit for patients with advanced non-small cell lung cancer (NSCLC). However, resistance to ICIs remains a major clinical challenge. Here, we perform a comprehensive bioinformatic analysis of plasma proteomic profiles to explore the underlying biology of treatment resistance in NSCLC.

METHODS: The analysis was performed on 388 "resistance-associated proteins" (RAPs) that were previously described as pretreatment plasma proteomic predictors within the PROphet computational model designed to predict ICI clinical benefit in NSCLC. Putative tissue origins of the RAPs were explored using publicly available datasets. Enrichment analyses were performed to investigate RAP-related biological …

Treatment Outcomes Following Tme For Biologically Unfavorable Locally Advanced Rectal Cancer, Maryam Aleissa, Amr Aref, Hussein Gharib, Ernesto R. Drelichman, Amer Zeni, Amer Alame, Jasneet S. Bhullar

Conference Presentation Abstracts

Purpose/Background: Many centers now offer organ preservation for selected patients with locally advanced rectal cancer. Our group initiated three Phase II trials to assess the safety of this approach in various clinical scenarios. Nonoperative management was recommended only for patients achieving complete clinical response CCR)after total neoadjuvant therapy TNT. Total mesorectal excision TME was advised when CCR was not achieved (primary TME), following residual cancer after Limited Local Excision LLE (completion TME), or after tumor recurrence/regrowth post-LLE or watchful waiting WW (salvage TME). This study examines treatment outcomes following primary or salvage TME in these biologically unfavorable cases.

Methods/Interventions: Each …

Comparison Of Magnetic Resonance Imaging (Mri) And Endoluminal Endoscopic Ultrasound (Eus) For Restaging Rectal Cancer After Neoadjuvant Chemotherapy, Judy Sheffeh, Amr Aref, Mohammed Barawi, Amer Alame, Amer Zeni, Ernesto R. Drelichman, Jasneet S. Bhullar

Conference Presentation Abstracts

Purpose/Background: Given the high incidence and mortality of rectal cancer, accurate staging and restaging are crucial for guiding optimal interventions. However, no consensus exists on the best imaging modality for restaging after neoadjuvant chemoradiotherapy. This study aims to compare MRI and EUS in the restaging of rectal cancer following neoadjuvant chemoradiotherapy.

Methods/Interventions: We conducted a prospective observational study and enrolled patients with rectal cancer. EUS and MRI were performed at diagnosis for initial staging and repeated after neoadjuvant chemotherapy and chemoradiotherapy for restaging. A total of 43 patients were enrolled, with 25 patients (10 males, 15 females) with rectal cancer …

Real-World Management Of High-Risk Prostate Cancer Post-Radical Prostatectomy: Insights From A Regional Quality Collaborative, Aaron R. Hochberg, Annie H. Ho, Rasheed A. M. Thompson, Matthew B. Buck, Costas D. Lallas, Christine Ibilibor, Jeffrey J. Tomaszewski, Serge Ginzburg, Andres Correa, Robert Uzzo, Marc C. Smaldone, John F. Danella, Thomas J. Guzzo, Daniel J. Lee, Laurence Belkoff, Jeffrey Walker, Jay D. Raman, Roderick K. Clark, Adam Reese, Bruce Jacobs, Thomas Jang, Keith J. Kowalczyk, Meghan Smith, Mihir S. Shah

Department of Urology Faculty Papers

Background/Objectives: Data from clinical trials showing the non-inferiority of early salvage radiotherapy were recently incorporated into societal guideline statements. However, questions remain regarding ideal prostate-specific antigen (PSA) criteria for salvage, and how to apply these findings to pathologic lymph node-positive (pN+) disease. We investigated variance in management of clinically localized prostate cancer found to have high-risk features after radical prostatectomy. Methods: We retrospectively identified patients from May 2015 to January 2024 utilizing a multi-institutional, regional collaborative database. The primary outcome was identifying factors associated with the receipt of adjuvant versus salvage therapy. Factors associated with secondary treatment were assessed via …

Can Anemia Be A Prognostic Indicator To Scope For Gastroesophageal Junction Adenocarcinoma?, Ryan Tam, Neha Narayanan, Evan Basha, Joel Thompson

Advances in Clinical Medical Research and Healthcare Delivery

Gastroesophageal junction adenocarcinoma is a rapidly progressive disease that has a poor prognosis with a 5-year survival rate of 20%. It commonly presents with major symptoms of dysphagia and weight loss in addition to a long-standing history of reflux. As of now, screening for esophageal adenocarcinoma (EAC) is dependent on identifying risk factors which include a family history of Barrett’s esophagus and esophageal adenocarcinoma or patients with gastroesophageal reflux disease and at least one other risk factory for EAC such as age greater than 50 years, obesity or central adiposity, history of smoking, or male gender. Here, we present a …

Impact Of Post-Operative Radiation Therapy On Survival In Nsclc Patients With Incomplete Surgical Resection, Farrah R. Khan Md

Posters

Postoperative radiation therapy (PORT) has a limited role in the management of resectable non-small cell lung carcinoma (NSCLC). A relatively strong indication for its use is in the presence of residual tumor after surgical resection, as PORT has been shown to improve survival in such patients. However, it is unclear how much of the survival detriment of incomplete resection PORT is able to offset compared to negative margins. We aim to answer this question in our study

Toxicity And Clinical Outcomes Following Brachytherapy Using 3-D Dosimetric Planning In Patients With Cervical Cancer: An Institutional Experience, Nikita M. Patel, Jacob F. Oyeniyi, Maha Saada Jawad

Posters

• Cervical cancer is the most common gynecological cancer worldwide.1

• The standard of care for locally advanced cervical cancer (LACC) includes primary chemoradiation, brachytherapy, and external-beam radiotherapy.2

• Brachytherapy (BT) involves the targeted delivery of radiation to the cervix (Fig 1). However, radiation can be toxic to surrounding structures, most commonly affecting the gynecological, genitourinary, and gastrointestinal systems.3

• Historically, brachytherapy was planned using a 2-D approach, which had limitations in accuracy and increased toxicity to the adjacent bowel and bladder. 3-D planning using CT or MRI has been shown to have improved dose precision and reduced toxicity.4

• …

Advances In Minimally Invasive Hepatobiliary Interventions For Non-Operative Candidates, Tulasi Talluri, Philip Cieplinski, Kristian Loveridge

Posters

Cholangioscopy is a technique used for diagnosing and treating patients with pathologies of the gallbladder, liver, and pancreas. It has been available since 1976 but with limited use in interventional radiology (IR) due to issues with steerability, irrigation capabilities, requirement for more than one operator, and poor percutaneous access options; however, direct intraluminal visualization of the gallbladder, common bile ducts, and even the ampulla and duodenum has become more practical with the advent of single operator percutaneous systems. Access to the biliary system can now be made through smaller 11 French sheath/delivery systems allowing for improved maneuverability into the common …

Comparison Of Two Adjuvant High-Dose Rate Vaginal Cuff Brachytherapy Dose Fractionation Regimens For Treatment Of Early-Stage Uterine Cancer, Catherine Raciti, Hong Ye, Allison J. Hazy, Maha Saada Jawad

Posters

• Endometrial cancer is the most common gynecologic malignancy in the United States, with peak incidence at 63 years of age.¹

• PORTEC-2 trial established VBT alone as an effective modality for select high-intermediate risk patients.2

• There was no strict ABS guideline for dose fractionation; our institution adopted a 30Gy in 6 fractions regimen based on radiobiological calculations.3,4

• COVID-19 pandemic led to a shift towards 22Gy in 4 fractions

• Objective: Compare oncologic outcomes and toxicity between the 30Gy/6fx and 22Gy/4fx regimens.

• Hypothesis: Both regimens are well-tolerated and equally effective.

• Impact: Findings will inform clinical practice …

Automated Radiotherapy Treatment Planning For Breast Cancer: A Robust To Ol For Global Deployment, Hana Baroudi

Dissertations and Theses (Open Access)

Breast cancer incidence continues to rise worldwide, particularly in low- and middle-income countries, where limitations in resources already constrain access to timely care. Radiotherapy is a cornerstone of breast cancer management, proven to significantly lower both recurrence and mortality. However, a growing shortage of radiation staff worldwide threatens the prompt delivery of these treatments.This thesis proposes an automated solution to address the limited accessibility of radiotherapy planning in breast cancer management by developing an end-to-end automated treatment planning model and evaluating its performance and limitations across diverse patient populations.

An automated contouring model was trained using data from 104 whole-breast …

Development Of Lineal Energy Spectrum-Based Biological Effects Models For Protons, Joseph M. Decunha, Fada Guan, David Grosshans, Zhongxing Liao, Dragan Mirkovic, Oleg Vassiliev, Radhe Mohan

Dissertations and Theses (Open Access)

In this dissertation, methods are developed and described to allow for the rapid calculation of microdosimetric spectra (specifically, lineal energy) for protons. SuperTrack, a GPU-accelerated tool for calculation of microdosimetric spectra was developed and is capable of computing lineal energy spectra up to 5000x faster than using Geant4 directly. Proton lineal energy spectra generated by SuperTrack are indistinguishable from those generated by Geant4. With SuperTrack, large libraries of lineal energy spectra for monoenergetic protons spanning 0-300 MeV have been developed. The proton lineal energy spectra calculated by SuperTrack have been compared to experimental measurements made by a tissue equivalent proportional …

Percutaneous Transluminal Angioplasty And Stenting (Ptas) In Patients With Symptomatic Intracranial Vertebrobasilar Artery Stenosis (Ivbs), Ramtin Pourahmad, Kiarash Saleki, Sina Zoghi, Ramtin Hajibeygi, Hamed Ghorani, Amin Javanbakht, Sina Goodarzi, Parsa Alijanizadeh, Kelly Trinh, Ravi Shastri, Mohammad Ghasemi-Rad

Faculty, Staff and Students Publications

Background: Approximately 20% of all transient ischaemic attacks (TIAs) and ischaemic strokes occur within the posterior circulation, with vertebrobasilar stenosis identified as the cause in roughly 25% of the cases. Studies have shown that about a quarter of these patients have atherosclerotic stenosis of at least 50% of the vertebrobasilar artery. Stenosis has been shown to be associated with an increased risk of 90-day recurrent vertebrobasilar stroke, particularly in the first few weeks, which is significantly higher when compared with patients with stenosis of the anterior circulation. Therefore, aggressive treatment is important for the patient's prognosis. Stenting is emerging as …

Primary Central Nervous System Lymphoma: Predictors Of Response To Induction Therapy And Patterns Of Progression, Louis Cappelli, Allison Kayne, Jennifer Newman, Ahmed Elguindy, Narendranath Epperla, Joshua D. Palmer, Ubaldo E. Martinez-Outshoorn, Pierluigi Porcu, Wenyin Shi, Iyad Alnahhas

Department of Radiation Oncology Faculty Papers

BACKGROUND: Primary central nervous system lymphoma (PCNSL) is a rare and aggressive variant of non-Hodgkin lymphoma. While PCNSL is often sensitive to induction high-dose methotrexate (HDMTX) based chemotherapy, recurrence rates remain high, approaching 50% within 5 years. The most common molecular alterations in PCNSL include mutations in MYD88 and CD79 and CDKN2A homozygous deletion. There are no predictive or prognostic molecular markers in PCNSL.

METHODS: We conducted a retrospective review of 40 patients with PCNSL treated at Thomas Jefferson University and Ohio State University between 2011 and 2023. We created a clinically annotated database of patient characteristics and outcomes. For …

Desmoplastic Small Round Cell Tumor: An Update Of Current Management Practices, Ahmed Gawash, Alexa Simonetti, Brandon J Goodwin, Alissa Brotman O'Neill

Rowan-Virtua School of Osteopathic Medicine Departmental Research

BACKGROUND: Desmoplastic small round cell tumor (DSRCT) poses a diagnostic challenge, initiating with imaging techniques like ultrasound, CT, MRI, and PET scans, with CT being the primary choice for abdominal tumor visualization. Despite advances, the absence of a standardized staging system complicates the diagnostic process.

METHODS: A comprehensive literature review and search strategy, encompassing databases like PubMed and Cochrane was performed.

RESULTS: Systemic chemotherapy, notably the P6 regimen, is the cornerstone of DSRCT treatment, while other options, including CDK4/6 inhibitors, antibody-drug conjugates, and anlotinib present varying efficacy. A novel chemotherapeutic agent, ONC-201, exhibits promise, inhibiting tumor growth in preclinical models. …

3d-Printed Organ-Realistic Phantoms To Verify Quantitative Spect/Ct Accuracy For 177lu-Psma-617 Treatment Planning, Lydia J. Wilson, Sara Belko, Eric L. Gingold, Shuying Wan, Rachel Monane, Robert S. Pugliese, Firas Mourtada

Department of Radiation Oncology Faculty Papers

Background/Objectives: Accurate patient-specific dosimetry is essential for optimizing radiopharmaceutical therapy (RPT), but current tools lack validation in clinically realistic conditions. This work aimed to develop a workflow for designing and fabricating patient-derived, organ-realistic RPT phantoms and evaluate their feasibility for commissioning patient-specific RPT radioactivity quantification. Methods: We used computed tomographic (CT) and magnetic resonance (MR) imaging of representative patients, computer-aided design, and in-house 3D printing technology to design and fabricate anthropomorphic kidney and parotid phantoms with realistic organ spacing, anatomically correct orientation, and surrounding tissue heterogeneities. We evaluated the fabrication process via geometric verification (i.e., volume comparisons) and leak testing …

Evaluating Artifact-Free Four-Dimensional Computer Tomography With 16 Cm Detector Array, Inhwan Yeo, Wei Nie, Jiajin Fan, Mindy Joo, Michael Correa, Qianyi Xu

Department of Radiation Oncology Faculty Papers

PURPOSE: To evaluate a 16 cm-array axial four-dimensional computer tomography (4DCT) in comparison with a 4 cm-array 4DCT in the presence of respiration irregularity.

METHOD: Ten traces of lung tumor motion from CyberKnife treatments were imported to move the lung cylinder, containing a spherical target, of a phantom. Images were acquired for the lung that moved to each of the 10-positions/phases (1) step-wisely by nominal helical scan at each movement (ground truth), (2) continuously by 4D scan with the 16 cm array, and (3) the same with the 4 cm array, involving table shift. Irregularities, consisting of baseline shift and/or …