Radiation Medicine Commons^™

Vidutolimod In Combination With Atezolizumab With And Without Radiation Therapy In Patients With Programmed Cell Death Protein 1 Or Programmed Death-Ligand 1 Blockade-Resistant Advanced Nsclc, Marcelo V Negrao, Vassiliki A Papadimitrakopoulou, Andrew C Price, Alda L Tam, Muhammad Furqan, Sandeep T Laroia, Erminia Massarelli, Jose Pacheco, John V Heymach, Anne S Tsao, Gary V Walker, Lalit Vora, David Mauro, Heather Kelley, James E Wooldridge, Arthur M Krieg, Jiaxin Niu

Faculty, Staff and Student Publications

INTRODUCTION: Vidutolimod, a CpG-A TLR9 agonist, was investigated in a phase 1b study (CMP-001-003; ClinicalTrials.gov, NCT03438318) in combination with atezolizumab with and without radiation therapy (RT) in patients with advanced NSCLC.

METHODS: Patients with progressive disease after anti-programmed cell death protein 1 or programmed death-ligand 1 therapy received either vidutolimod and atezolizumab (part A) or vidutolimod, atezolizumab, and RT (part B). The primary objective was to evaluate the safety of vidutolimod and atezolizumab with and without RT. Key secondary end point was best objective response rate per Response Evaluation Criteria in Solid Tumors, version 1.1.

RESULTS: Between March 28, 2018, …

Physician Perspectives On Telemedicine In Radiation Oncology, Sean Maroongroge, Brian De, Kristina D Woodhouse, Roland L Bassett, Percy Lee, Elizabeth S Bloom, Grace L Smith, Steven J Frank, Jing Li, George Perkins, Prajnan Das, Albert C Koong, Benjamin D Smith, Chenyang Wang

Faculty, Staff and Student Publications

PURPOSE: Telemedicine enthusiasm and uptake in radiation oncology rapidly increased during the COVID-19 pandemic, but it is unclear if and how telemedicine should be used after the COVID-19 public health emergency ends is unclear. Herein, we report on our institution's provider experience after the mature adoption of telemedicine.

METHODS AND MATERIALS: We distributed a survey to all radiation oncology attending physicians at our institution in October 2021 to assess satisfaction, facilitators, and barriers to telemedicine implementation. We performed quantitative and qualitative analyses to characterize satisfaction and identify influencing factors whether telemedicine is employed. We calculated the average proportion of visits …

Multisite Detection Of Tn1549-Mediated Vanb Vancomycin Resistance In Multidrug-Resistant Enterococcus Faecalis St6 In Texas And Florida, Shelby R Simar, Truc T Tran, Kirsten B Rydell, Diana Panesso, German A Contreras, Jose M Munita, Renzo O Cifuentes, Lilian M Abbo, Pranoti Sahasrabhojane, An Q Dinh, Dierdre B Axell-House, Tor Savidge, Samuel A Shelburne, Blake M Hanson, Cesar A Arias

Faculty, Staff and Student Publications

In the United States, vanB-mediated resistance in enterococci is rare. We characterized three sequence type (ST) 6, vancomycin-resistant Enterococcus faecalis isolates causing bacteremia in unique patients in spatiotemporally distinct settings. Isolates were recovered between 2018 and 2020 in two cities in the United States (Houston, TX; Miami, FL). The isolates harbored the vanB operon on a chromosomally located Tn1549 transposon, and epidemiological data suggested multiple introductions of the vanB gene cluster into ST6 E. faecalis.

Radiation Therapy For Retroperitoneal Sarcomas: A Strass-Ful Situation, Ahsan S Farooqi, B Ashleigh Guadagnolo, Devarati Mitra, Andrew J Bishop

Faculty, Staff and Student Publications

Locoregional recurrence (LRR) is the predominant pattern of relapse and often the cause of death in patients with retroperitoneal sarcomas (RPS). As a result, reducing LRR is a critical objective for RPS patients. However, unlike soft tissue sarcomas (STS) of the superficial trunk and extremity where the benefits of radiation therapy (RT) are well-established, the role of RT in the retroperitoneum remains controversial. Historically, preoperative or postoperative RT, either alone or in combination with intraoperative radiation (IORT), was commonly justified for RPS based on extrapolation from the superficial trunk and extremity STS literature. However, long-awaited results were recently published from …

Determination Of Kinetic Parameters For Bone Turnover In Chronic Kidney Disease With Hemodialysis Patients Using Dynamics 18f-Naf Pet/Ct Imaging, Viyada Sanoesan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Bone turnover measurement using 18F-NaF PET/CT serves as a valuable imaging biomarker for studying bone metabolism at various sites of skeleton. This study aimed to determine the kinetic parameters (Ki–Patlak) for bone turnover prediction as a non-invasive biomarker from dynamic 18F-NaF PET/CT in chronic kidney disease (CKD) patients with hemodialysis. Moreover, we aimed to investigate whether Ki–Patlak derived from shortened scan time can provide a prediction equivalent to that obtained from routine dynamic scan. Twenty-seven Thai CKD patients on hemodialysis (48 scans) from December 2021 to December 2023 were recruited. After intravenous injection of 18F-NaF of 133±39.3 MBq, dynamic PET/CT …

Accuracy Of 177lu Quantification For Dosimetry Calculation Using 12-Swiveling Czt Detectors Spect/Ct Camera, Panattha Damthongsen

Chulalongkorn University Theses and Dissertations (Chula ETD)

Recently, the 12-cadmium zinc telluride (CZT) based digital detectors SPECT/CT system has been introduced for advanced technology in nuclear medicine instrument, which outperforms conventional cameras. Moreover, the voxel S value-based dosimetry is important and offers more accurate in personalized dosimetry treatment using targeted radionuclide therapy. This study aimed to determine the accuracy of 177Lu quantification through an IEC/NEMA phantom study and to evaluate total-body dosimetry in patients undergoing 177Lu therapy using 12-swiveling digital CZT detectors SPECT/CT camera. The NEMA/IEC body phantom inserted with six fillable spheres (10-, 13-, 17-, 22-, 28-, and 37-mm inner diameter), filled with 177Lu solution of …

Impact Of Contrast Agent Administration On Water Equivalent Diameter For Ssde Calculation In Chest Ct Angiography Examination, Nuttanit Kaewsan

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to determine the impact of intravenous contrast enhancement on the calculation of water equivalent diameter (Dw) for size-specific dose estimate (SSDE) in chest CT angiography (CTA) using different calculation methods in non-contrast and arterial phase images. A cohort of 231 adult patients who underwent chest CT angiography at King Chulalongkorn Memorial Hospital (KCMH) were included. The 3D Slicer image computing software was used to automatically draw the ROI in each axial CT image to measure area and mean CT number. The Dw values were calculated following the American Association of Physicists in Medicine (AAPM) Report No.220 utilizing …

Improving Radiotherapy Workflow: Evaluation And Implementation Of Deep Learning Auto-Segmentation In A Multi-User Environment, And Development Of Automatic Contour Quality Assurance System, Jingwei Duan

Theses and Dissertations--Radiation Medicine

Radiotherapy is a frequently used therapeutic modality for cancer patients. Accurately contouring of tumors and organs at risk (OARs) is critical for developing optimal treatment plans in radiotherapy, especially after the implementation of Intensity-modulated radiation therapy (IMRT) and Stereotactic Body Radiation Therapy (SBRT). The manual contouring process is time-consuming and suffers from inter-observer variations. However, manual contouring is often hindered by laborious clinical duties, leading to reduced effectiveness, and increased segmentation errors due to fatigue. Additionally, online adaptive radiation therapy(ART), which has been shown to benefit patient outcomes, places higher demands on contouring and quality assurance (QA) speed.

Recently, deep …

Analysis Of Biologically Effective Dose For Retroactive Yttrium-90 Trans-Arterial Radioembolization Treatment Optimization, Mj Lindsey

CMC Senior Theses

Trans-arterial radioembolization (TARE) is a protracted modality of radiation therapy where radionuclides labeled with Yttrium-90 (⁹⁰Y) are inserted inside a patient's hepatic artery to treat hepatocellular carcinoma (HCC). While TARE has been shown to be a clinically effective and safe treatment, there is little understanding of the radiobiological relationship between absorbed dose and tissue response, and thus there is no dosimetric standard for treatment planning. The Biologically Effective Dose (BED) formalism, derived from the Linear-Quadratic model of radiobiology, is used to weigh the absorbed dose by the time pattern of delivery. BED is a virtual dose that can …

Radiation-Induced Gastrointestinal (Gi) Syndrome As A Function Of Age, Hongyan Li, Herman C. Kucharavy, Carla Hajj, Liyang Zhao, Guoqiang Hua, Ryan Glass, Phillip B. Paty, Zvi Fuks, Richard Kolesnick, Karen Hubbard, Adriana Haimovitz-Friedman

Publications and Research

Previous studies show increased sensitivity of older mice (28–29 months) compared with young adult mice (3 months, possessing a mature immune system) to radiation-induced GI lethality. Age-dependent lethality was associated with higher levels of apoptotic stem cells in small intestinal crypts that correlated with sphingomyelinase activity, a source of pro-apoptotic ceramide. The objective of this study is to determine whether the cycling crypt base columnar cells (CBCs) in aging animals are specifically more sensitive to radiation effects than the CBCs in young adult mice, and to identify factors that contribute to increased radiosensitivity. Mortality induced by subtotal body radiation was …

Evaluation Of Patient Radiation Dose And Risk Of Cancer From Ct Examinations, Saowapark Poosiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Computed Tomography (CT) examinations have been increasingly requested and become the major sources of patient exposure. The cancer risk from CT scans is contingent upon the amount of organ absorbed dose. This study aims to evaluate the cumulative effective doses (CED) and risk of cancer incidence and mortality from recurrent CT examinations in a single day. The patient data at aged 15 to 75 years old performed CT examinations during the period of five years from January 2018 to December 2022 were collected from two academic centers. The CED and organ doses were evaluated using Radimetrics™ Enterprise Platform from Monte …

Comparison Of Modified Formalism Output And Trs-398 Absorbed Dose To Water In Electron Beams Reference Dosimetry In Multiple Radiotherapy Centers, Yasumon Thinka

Chulalongkorn University Theses and Dissertations (Chula ETD)

The study aimed to investigate the feasibility and efficacy of utilizing modified calibration with cylindrical chambers for reference dosimetry in electron beam radiotherapy, challenging the recommendation of using plane-parallel chambers in low-energy electron beams by IAEA's TRS-398 and AAPM's TG-51 standards. Data collection involved six radiotherapy centers in Bangkok using Varian linear accelerators, with chambers including the IBA FC65-G, PTW 30013 cylindrical chambers, and PPC40, Roos plane-parallel chambers. Results of dose comparison between modified and TRS-398 protocols fell within ±2%. For low-energy electron beams, percent dose discrepancies ranged from -1.57% to 0.91%, and from -0.37% to 0.91% for high-energy. The …

Characteristics Of Two-Dimensional Ionization Chamber Array For Patient-Specific Quality Assurance In Pencil Beam Scanning Proton Therapy, Nuttida Rawiwan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Proton therapy is an advanced technique that uses positive particles in external treatment. It can spare normal tissue and increase tumor control probability. In radiotherapy, patient-specific quality assurance is an important part, but according to protons’ characteristics, especially finite range, it is challenging to do verification because when the density has changed the finite range will have drastic changes. Although the two-dimensional ionization chamber array is used for patient-specific quality assurance in pencil beam scanning proton therapy, most studies investigate the IBA MatriXX as the dosimetry device, and few studies explored the PTW OCTAVIUS 1500XDR. This research aims to determine …

Determination Of The Surface Dose Correction Factors For Various Detectors In Proton Scanning Therapy, Pakjira Saruang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Proton therapy delivers tumors doses precisely but concerns about skin toxicity due to energy dispersion beyond the Bragg peak remain. Accurate surface dose measurement is crucial for calculating the radiation dose patients receive. Studying factors that improve measurement accuracy is essential, as current methods are challenging and often inaccurate. This research aims to determine the surface dose correction factors (Scf) for various detectors in spot scanning beam proton therapy and study the effect of surface dose according to various clinical factors. The PTW Advanced Markus, PTW Roos chamber and IBA FC65-G Farmer chamber were utilized to measure the surface dose …

Dosimetric Comparison Of Imrt, Co-Planar Vmat, Non-Coplanar Vmat And Hyperarc For Multiple Brain Metastases Srs, Aksarapak Thawornnittayakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Multiple brain metastases patients are typically treated by stereotactic radiosurgery (SRS) or whole brain radiation therapy (WBRT). In addition, there are advanced techniques for treating multiple brain metastases such as 3-dimensional Conformal Radiation Therapy (3D-CRT), Intensity Modulated Radiation Therapy (IMRT), and Volumetric Modulated Arc Therapy (VMAT). A new isocentric VMAT technique called HyperArc was developed for non-coplanar, it is an automated setting for couch angle and collimator angle. This study aims to compare the dosimetric effect for a single isocenter among Intensity Modulated Radiation Therapy, Volumetric Modulated Arc Therapy, and HyperArc for multiple brain metastases stereotactic radiosurgery. For 25 patients …

Dose Evaluation Of A Deep Learning-Based Synthetic Ct Generation In Head And Neck Cancer For Photon And Proton Therapy, Ailada Kuibumrung

Chulalongkorn University Theses and Dissertations (Chula ETD)

MRI has been increasingly implemented for the treatment planning process and the MRI-only workflow in both photon and proton therapy. This study aims to investigate and explore the accuracy of dose calculations in head and neck region based on synthetic CT (sCT) images, using the commercial software methods for both volumetric modulated arc therapy (VMAT) and intensity modulated proton therapy (IMPT) plans. The sCT images were generated from MRI images for five head and neck cancer cases that underwent VMAT and IMPT by MRI Planner commercial software. The mean absolute error (MAE) and mean error (ME) within the body, bone …

Breast Cancer Characterization Using Artificial Intelligence In Screening And Diagnostic Mammogram Of Thai Women, Jaroonroj Wongnil

Chulalongkorn University Theses and Dissertations (Chula ETD)

Breast cancer is a significant health issue in Thailand, necessitating accurate detection and characterization for effective treatment. This thesis focuses on leveraging artificial intelligence techniques to develop breast cancer screening and diagnosis using mammography images of Thai women. Furthermore, detecting and classifying mammography calcifications, crucial indicators of malignant or benign conditions had also been focused using RCNN and YOLOv4 in this study. AlexNet CNN was developed to increase the robustness of the RCNN model. AlexNet was tested with three different datasets, each consisting of 4,000 cropped ROI images. These datasets were divided into an 80% training set and a 20% …

Head And Neck Radiation Therapy Patterns Of Practice Variability Identified As A Challenge To Real-World Big Data: Results From The Learning From Analysis Of Multicentre Big Data Aggregation (Lambda) Consortium, Amanda Caissie, Michelle Mierzwa, Clifton David Fuller, Murali Rajaraman, Alex Lin, Andrew Macdonald, Richard Popple, Ying Xiao, Lisanne Vandijk, Peter Balter, Helen Fong, Heping Xu, Matthew Kovoor, Joonsang Lee, Arvind Rao, Mary Martel, Reid Thompson, Brandon Merz, John Yao, Charles Mayo

Faculty, Staff and Student Publications

PURPOSE: Outside of randomized clinical trials, it is difficult to develop clinically relevant evidence-based recommendations for radiation therapy (RT) practice guidelines owing to lack of comprehensive real-world data. To address this knowledge gap, we formed the Learning from Analysis of Multicenter Big Data Aggregation consortium to cooperatively implement RT data standardization, develop software solutions for data analysis, and recommend clinical practice change based on real-world data analyzed. The first phase of this "Big Data" study aimed at characterizing variability in clinical practice patterns of dosimetric data for organs at risk (OARs) that would undermine subsequent use of large-scale, electronically aggregated …

Dose Escalation For Pancreas Sbrt: Potential And Limitations Of Using Daily Online Adaptive Radiation Therapy And An Iterative Isotoxicity Automated Planning Approach, Dong Joo Rhee, Sam Beddar, Joseph Abi Jaoude, Gabriel Sawakuchi, Rachael Martin, Luis Perles, Cenji Yu, Yulun He, Laurence E Court, Ethan B Ludmir, Albert C Koong, Prajnan Das, Eugene J Koay, Cullen Taniguichi, Joshua S Niedzielski

Faculty, Staff and Student Publications

PURPOSE: To determine the dosimetric limitations of daily online adaptive pancreas stereotactic body radiation treatment by using an automated dose escalation approach.

METHODS AND MATERIALS: We collected 108 planning and daily computed tomography (CT) scans from 18 patients (18 patients × 6 CT scans) who received 5-fraction pancreas stereotactic body radiation treatment at MD Anderson Cancer Center. Dose metrics from the original non-dose-escalated clinical plan (non-DE), the dose-escalated plan created on the original planning CT (DE-ORI), and the dose-escalated plan created on daily adaptive radiation therapy CT (DE-ART) were analyzed. We developed a dose-escalation planning algorithm within the radiation treatment …

Predictive Digital Twin For Optimizing Patient-Specific Radiotherapy Regimens Under Uncertainty In High-Grade Gliomas, Anirban Chaudhuri, Graham Pash, David A Hormuth, Guillermo Lorenzo, Michael Kapteyn, Chengyue Wu, Ernesto A B F Lima, Thomas E Yankeelov, Karen Willcox

Faculty, Staff and Student Publications

We develop a methodology to create data-driven predictive digital twins for optimal risk-aware clinical decision-making. We illustrate the methodology as an enabler for an anticipatory personalized treatment that accounts for uncertainties in the underlying tumor biology in high-grade gliomas, where heterogeneity in the response to standard-of-care (SOC) radiotherapy contributes to sub-optimal patient outcomes. The digital twin is initialized through prior distributions derived from population-level clinical data in the literature for a mechanistic model's parameters. Then the digital twin is personalized using Bayesian model calibration for assimilating patient-specific magnetic resonance imaging data. The calibrated digital twin is used to propose optimal …