Radiation Medicine Commons^™

Dosimetric Comparison Between Single-Energy Ct And Dual-Energy Ct For Relative Stopping Power Estimation In Proton Therapy, Thamonwan Chirdchid

Chulalongkorn University Theses and Dissertations (Chula ETD)

In proton therapy treatment planning, dose calculation requires CT calibration curve by relating CT number (HU) to relative stopping power to water (RSP). The CT calibration curve and the RSP validation are described for single-energy CT (SECT) and dual-energy CT (DECT). The focus of this work was given on the dosimetric comparison of treatment plans between SECT and DECT-based dose calculation. The 062M CIRS phantom was scanned to access the HU values by GE kVp switching method with single-energy of 120 kVp and dual-energy of 80/140 kVp. The CT calibration curve was generated using the stoichiometric calibration method and implemented …

Tolerance Levels On Dose And Anatomic Variation For Adaptive Radiotherapy Based On Statistical Process Control For Nasopharyngeal Cancer, Rudjaya Intaprom

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nasopharyngeal cancer (NPC) is one of the most common cancers in Thailand and worldwide. During the long course of treatment, patients often change of anatomy in both the shape and the volume. The deviation of the delivered dose has long been a clinical concern. Adaptive radiotherapy (ART) technique is a treatment process that prevents the dose changes to clinical target volume (CTV) and organs at risk (OARs). The purpose of this study was proposed to method to set the action levels for replanning in NPC and to evaluate the dose differences of CTV and OARs by planning CT and weekly …

The Study Of Local Diagnostic Reference Levels Of Computed Tomography Procedures At Phramongkutklao Hospital, Sutasinee Mahasub

Chulalongkorn University Theses and Dissertations (Chula ETD)

Computed Tomography (CT) is a medical modality of 3D imaging technique using the X-ray photons rotate, transmit and detect the radiation by the multi-detectors. The CT examination results in the higher patient dose than the general radiography. The objective of this study was to establish the Local DRLs of patient radiation dose in CT procedures at Phramongkutklao Hospital. This study is a retrospective analysis at a single center from January-August 2021. Two CT scanners: 160 slices MDCT manufactured by Canon, model AquilionTM Prime and 640 slices MDCT manufactured by Canon, model AquilionTM One Prism have been used to collect the …

Automated Method Of Corrected Effective Diameter For Ssde In Thoracic Imaging Ct Using Cnn, Sakultala Ruenjit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to automatically determine the corrected effective diameter (Deffcorr) using convolutional neural network (CNN) for simplified SSDE calculation in thoracic CT. Transaxial images of 108 adult patients underwent thoracic CT without contrast at King Chulalongkorn Memorial Hospital (KCMH) were collected. To calculate the Deffcorr according to Mihailidis et al., the average relative electron densities for lung tissue (ρelung=0.3), for other tissues (ρetissue=1.0) and for bone (ρebone=1.2) were employed to correct the lateral and anteroposterior dimension. The CNN network architecture based on the U-Net algorithm was used for automated image segmentation. The 108 thoracic CT images and generated segmentation …

The Potential Of Biology-Guided Radiation Therapy In Thoracic Cancer: A Preliminary Treatment Planning Study, Steven N Seyedin, Rostem Bassalow, Osama R Mawlawi, Lehendrick M Turner, Roshal R Patel, Samuel R Mazin, Oluwaseyi M Oderinde, Yevgen Voronenko, Cody A Wages, Peter D Olcott, Joe Y Chang, Peter A Balter, James W Welsh

Faculty, Staff and Student Publications

PURPOSE: We investigated the feasibility of biology-guided radiotherapy (BgRT), a technique that utilizes real-time positron emission imaging to minimize tumor motion uncertainties, to spare nearby organs at risk.

METHODS: Volumetric modulated arc therapy (VMAT), intensity-modulated proton (IMPT) therapy, and BgRT plans were created for a paratracheal node recurrence (case 1; 60 Gy in 10 fractions) and a primary peripheral left upper lobe adenocarcinoma (case 2; 50 Gy in four fractions).

RESULTS: For case 1, BgRT produced lower bronchus V40 values compared to VMAT and IMPT. For case 2, total lung V20 was lower in the BgRT case compared to VMAT …

Multiagent Chemotherapy And Stereotactic Body Radiation Therapy In Patients With Unresectable Pancreatic Adenocarcinoma: A Prospective Nonrandomized Controlled Trial, Colin S Hill, Lauren Rosati, Hao Wang, Hua-Ling Tsai, Jin He, Amy Hacker-Prietz, Daniel A Laheru, Lei Zheng, Shuchi Sehgal, Vincent Bernard, Dung T Le, Timothy M Pawlik, Matthew J Weiss, Amol K Narang, Joseph M Herman

Faculty, Staff and Student Publications

PURPOSE: In a prospective multicenter study, gemcitabine monotherapy followed by stereotactic body radiation therapy (SBRT) was well tolerated with outcomes comparable to chemoradiation for locally advanced pancreatic cancer (LAPC). Recent trials have reported improved survival with multiagent chemotherapy (MA-CTX) alone. This prospective trial explored whether SBRT could be safely delivered after MA-CTX. Herein, we report the long-term outcomes of adding SBRT after MA-CTX in LAPC patients and evaluate whether genetic profiles of specimens obtained before SBRT influence outcomes.

METHODS AND MATERIALS: This prospective nonrandomized controlled phase 2 trial enrolled 44 LAPC and 4 locally recurrent patients after multidisciplinary evaluation between …

Personalized Nutrition As A Key Contributor To Improving Radiation Response In Breast Cancer, Anuradha A. Shastri, Joseph Lombardo, Samantha C Okere, Stephanie Higgins, Brittany C Smith, Tiziana Deangelis, Ajay Palagani, Kamryn Hines, Daniel A. Monti, Stella Volpe, Edith P. Mitchell, Nicole L Simone

Department of Radiation Oncology Faculty Papers

Understanding metabolic and immune regulation inherent to patient populations is key to improving the radiation response for our patients. To date, radiation therapy regimens are prescribed based on tumor type and stage. Patient populations who are noted to have a poor response to radiation such as those of African American descent, those who have obesity or metabolic syndrome, or senior adult oncology patients, should be considered for concurrent therapies with radiation that will improve response. Here, we explore these populations of breast cancer patients, who frequently display radiation resistance and increased mortality rates, and identify the molecular underpinnings that are, …

Verrucous Carcinoma Of The Vulva: Patterns Of Care And Treatment Outcomes., Sara M. Dryden, Leonid B. Reshko, Jeremy T. Gaskins, Scott R. Silva

Faculty and Staff Scholarship

Background: Verrucous vulvar carcinoma (VC) is an uncommon and distinct histologic subtype of squamous cell carcinoma (SCC). The available literature on VC is currently limited to case reports and small single institution studies. Aims: The goals of this study were to analyze data from the National Cancer Database (NCDB) to quantitate the incidence of VC and to investigate the effects of patient demographics, tumor characteristics, and treatment regimens on overall survival (OS) in women with verrucous vulvar carcinoma. Methods and results: Patients diagnosed with vulvar SCC or VC between the years of 2004 and 2016 were identified in the NCDB. …

Development Of A Financial Toxicity Screening Tool For Radiation Oncology: A Secondary Analysis Of A Pilot Prospective Patient-Reported Outcomes Study, Rahul N Prasad, Tejash Patel, Scott W Keith, Harriet Eldredge-Hindy, Scot A Fisher, Joshua D Palmer

Department of Radiation Oncology Faculty Papers

Purpose: Financial toxicity is highly prevalent in oncology. Early identification of at-risk patients is essential because financial toxicity is associated with inferior outcomes. Validated general oncology screening tools are cumbersome and not specific to challenges related to radiation therapy, such as daily treatments. In the population of radiation oncology patients, no standardized, validated, rapid screening tool exists. We sought to develop a rapid, no-cost, and reliable financial-toxicity screening tool for clinical radiation oncology.

Methods and materials: We retrospectively analyzed data from a prospective survey study conducted at a large referral center with a heterogeneous population. Before treatment, a 25-item modified …

Improved Radiation Expression Profiling In Blood By Sequential Application Of Sensitive And Specific Gene Signatures, Eliseos J. Mucaki, Ben C. Shirley, Peter K. Rogan

Biochemistry Publications

Purpose. Combinations of expressed genes can discriminate radiation-exposed from normal control blood samples by machine learning based signatures (with 8 to 20% misclassification rates). These signatures can quantify therapeutically-relevant as well as accidental radiation exposures. The prodromal symptoms of Acute Radiation Syndrome (ARS) overlap those present in Influenza and Dengue Fever infections. Surprisingly, these human radiation signatures misclassified gene expression profiles of virally infected samples as false positive exposures. The present study investigates these and other confounders, and then mitigates their impact on signature accuracy.

Methods. This study investigated recall by previous and novel radiation signatures independently derived …

Feasibility Evaluation Of Metamaterial Microwave Sensors For Non-Invasive Blood Glucose Monitoring, Lukas Malena, Ondrej Fiser, Paul R. Stauffer, Tomas Drizdal, Jan Vrba, David Vrba

Department of Radiation Oncology Faculty Papers

The use of microwave technology is currently under investigation for non-invasive estimation of glycemia in patients with diabetes. Due to their construction, metamaterial (MTM)-based sensors have the potential to provide higher sensitivity of the phase shift of the S21 parameter (∠S21 ) to changes in glucose concentration compared to standard microstrip transmission line (MSTL)-based sensors. In this study, a MSTL sensor and three MTM sensors with 5, 7, and 9 MTM unit cells are exposed to liquid phantoms with different dielectric properties mimicking a change in blood glucose concentration from 0 to 14 mmol/L. Numerical models were created for the …

Impact Of Lymphopenia On Survival For Elderly Patients With Glioblastoma: A Secondary Analysis Of The Cctg Ce.6 (Eortc 26062-22061, Trog03.01) Randomized Clinical Trial, Andrew Song, Keyue Ding, Iyad Alnahhas, Normand J Laperriere, James Perry, Warren P Mason, Chad Winch, Chris J O'Callaghan, Johan J Menten, Alba A Brandes, Claire Phillips, Michael F Fay, Ryo Nishikawa, David Osoba, J Gregory Cairncross, Wilson Roa, Wolfgang Wick, Wenyin Shi

Department of Radiation Oncology Faculty Papers

Background: Lymphopenia may lead to worse outcomes for glioblastoma patients. This study is a secondary analysis of the CCTG CE.6 trial evaluating the impact of chemotherapy and radiation on lymphopenia, and effects of lymphopenia on overall survival (OS).

Methods: CCTG CE.6 randomized elderly glioblastoma patients (≥ 65 years) to short-course radiation alone (RT) or short-course radiation with temozolomide (RT + TMZ). Lymphopenia (mild-moderate: grade 1-2; severe: grade 3-4) was defined per CTCAE v3.0, and measured at baseline, 1 week and 4 weeks post-RT. Preselected key factors for analysis included age, sex, ECOG, resection extent, MGMT methylation, Mini-Mental State Examination, and …

The Contribution Of Patient Reported Outcome Measures To Shared Decision-Making In Radiation Oncology At A Midwestern Comprehensive Cancer Center, Kellie Bodeker

Doctor of Philosophy in Translational Health Sciences Dissertations

Background. Chronic diseases, such as lung cancer, require a provider-patient relationship developed over time. This relationship fosters shared decision-making (SDM), a collaborative, dynamic information exchange and analysis between provider and patient regarding treatment and desired outcomes. Established benefits to SDM include an improved quality of life and decreased anxiety and depression. Despite established benefits, recent research suggests radiation oncologists are not engaging in SDM. A decision-aid tool utilizing patient reported outcome measures may increase SDM between radiation oncologists and patients with lung cancer. Patient-reported outcome measures, wherein the patient provides direct assessment of their health and quality of life, …

Conservatively Managed Chronic Bronchopleural Fistula After Lung Cancer Tri-Modality Therapy: A Case Report, Nilanjan Haldar, Christian Fernandez, Nathaniel R. Evans Iii, Maria Werner-Wasik

Division of Cardiology Faculty Papers

No abstract provided.

Fast Generation Of Lung Sbrt Plans With A Knowledge-Based Planning Model On Ring-Mounted Halcyon Linac, Justin Visak, Aaron Webster, Mark E. Bernard, Mahesh R. Kudrimoti, Marcus E. Randall, Ronald C. Mcgarry, Damodar Pokhrel

Radiation Medicine Faculty Publications

PURPOSE: To demonstrate fast treatment planning feasibility of stereotactic body radiation therapy (SBRT) for centrally located lung tumors on Halcyon Linac via a previously validated knowledge-based planning (KBP) model to support offline adaptive radiotherapy.

MATERIALS/METHODS: Twenty previously treated non-coplanar volumetric-modulated arc therapy (VMAT) lung SBRT plans (c-Truebeam) on SBRT-dedicated C-arm Truebeam Linac were selected. Patients received 50 Gy in five fractions. c-Truebeam plans were re-optimized for Halcyon manually (m-Halcyon) and with KBP model (k-Halcyon). Both m-Halcyon and k-Halcyon plans were normalized for identical or better target coverage than clinical c-Truebeam …

Predicting The Effect Of Indirect Cell Kill In The Treatment Of Multiple Brain Metastases Via Single-Isocenter/Multitarget Volumetric Modulated Arc Therapy Stereotactic Radiosurgery, Allison N. Palmiero, Denise Fabian, Marcus E. Randall, William St. Clair, Damodar Pokhrel

Radiation Medicine Faculty Publications

PURPOSE: Due to spatial uncertainty, patient setup errors are of major concern for radiosurgery of multiple brain metastases (m-bm) when using single-isocenter/multitarget (SIMT) volumetric modulated arc therapy (VMAT) techniques. However, recent clinical outcome studies show high rates of tumor local control for SIMT-VMAT. In addition to direct cell kill (DCK), another possible explanation includes the effects of indirect cell kill (ICK) via devascularization for a single dose of 15 Gy or more and by inducing a radiation immune intratumor response. This study quantifies the role of indirect cell death in dosimetric errors as a function of spatial patient setup uncertainty …

Dosimetric Evaluation Of Fixed Jaw And Jaw Tracking Vmat Treatment Plans For Prostate Cancer With Involved Pelvic Nodes, William Rios

Masters Projects

Intro

A mechanical limitation of modern linacs affecting the quality of radiotherapy treatments of large tumor volumes is the travel length of multicollimator leaves. Considering this limitation, research was carried out to evaluate the dosimetric differences between a split-field fixed-jaw volumetric arc radiotherapy (SF-FJ VMAT) technique and a jaw tracking VMAT (JT VMAT) technique for the treatment of prostate cancer with involved lymph nodes.

Methods

Plans for 16 patients treated with the same dose regimen were created using both techniques. Initial JT-VMAT plans were planned with two arcs to encompass the entire tumor volume without jaw restrictions and jaw tracking …

Interactive Machine Learning-Based Multi-Label Segmentation Of Solid Tumors And Organs, Dimitrios Bounias, Ashish Singh, Spyridon Bakas, Sarthak Pati, Saima Rathore, Hamed Akbari, Michel Bilello, Benjamin Greenberger, Joseph Lombardo, Rhea Chitalia, Nariman Jahani, Aimilia Gastounioti, Michelle Hershman, Leonid Roshkovan, Sharyn Katz, Bardia Yousefi, Carolyn Lou, Amber Simpson, Richard Do, Russell Shinohara, Despina Kontos, Konstantina Nikita, Christos Davatzikos

Department of Radiation Oncology Faculty Papers

We seek the development and evaluation of a fast, accurate, and consistent method for general-purpose segmentation, based on interactive machine learning (IML). To validate our method, we identified retrospective cohorts of 20 brain, 50 breast, and 50 lung cancer patients, as well as 20 spleen scans, with corresponding ground truth annotations. Utilizing very brief user training annotations and the adaptive geodesic distance transform, an ensemble of SVMs is trained, providing a patient-specific model applied to the whole image. Two experts segmented each cohort twice with our method and twice manually. The IML method was faster than manual annotation by 53.1% …

Mepilex Use In Breast Cancer Radiotherapy Patients, Yeuying Qiu, Sean Quinlan-Davidson Md

Research Scholars

No abstract provided.

Automation Of Radiation Treatment Planning For Cervical Cancer, Dong Joo Rhee

Dissertations and Theses (Open Access)

Cervical cancer is one of the most common cancer in low- and middle-income countries (LMICs). The mortality rate can be reduced if radiation treatment becomes widely available. However, due to the lack of radiation treatment facilities and human resources, many cervical cancer patients in Africa are not able to receive timely treatments or advanced therapies. To increase the availability of radiation treatment in low-and middle-income countries (LMICs) including African countries, many attempts have been made to reduce the cost of medical linear accelerators. However, increasing the number of treatment machines would not instantly resolve the issues, as there would be …