Radiation Medicine Commons^™

Tumor Treating Fields Increases Blood-Brain Barrier Permeability And Relative Cerebral Blood Volume In Patients With Glioblastoma, Michael Iv, Lewis Naya, Sajal Sanan, Samuel L Van Buskirk, Seema Nagpal, Reena P Thomas, Lawrence D Recht, Chirag B Patel

Faculty, Staff and Student Publications

BACKGROUND AND OBJECTIVE: 200 kHz tumor treating fields (TTFields) is clinically approved for newly-diagnosed glioblastoma (nGBM). Because its effects on conventional surveillance MRI brain scans are equivocal, we investigated its effects on perfusion MRI (pMRI) brain scans.

METHODS: Each patient underwent institutional standard pMRI: dynamic contrast-enhanced (DCE) and dynamic susceptibility contrast (DSC) pMRI at three time points: baseline, 2-, and 6-months on-adjuvant therapy. At each timepoint, the difference between T1 pre- versus post-contrast tumor volume (ΔT1) and these pMRI metrics were evaluated: normalized and standardized relative cerebral blood volume (nRCBV, sRCBV); fractional plasma volume (V

RESULTS: Among 13 pMRI datasets …

Pseudotumoral Hemicerebellitis In A Young Male Sailor With Complete Recovery After Steroid Therapy, Khizer Masroor Anns, Faheem Ullah Khan, Muhammad Aman, Anwar Ahmad, Kumail Khandwala, Zainab Aslam Saeed Memon, Izaz Ahmad, Muhammad Ismail Safi

Medical College Documents

Pseudotumoral hemicerebellitis is a rare presentation of acute cerebellitis, which involves the inflammation of a single cerebellar hemisphere and most commonly affects children. It mimics a tumor on imaging, hence given the name. In this report, we present a case of pseudotumoral hemicerebellitis in a 30-year-old male who presented to the emergency room (ER) with complaints of vertigo, vomiting, and a headache.

Predicting Radiotherapy Patient Outcomes With Real-Time Clinical Data Using Mathematical Modelling, Alexander P Browning, Thomas D Lewin, Ruth E Baker, Philip K Maini, Eduardo G Moros, Jimmy Caudell, Helen M Byrne, Heiko Enderling

Faculty, Staff and Student Publications

Longitudinal tumour volume data from head-and-neck cancer patients show that tumours of comparable pre-treatment size and stage may respond very differently to the same radiotherapy fractionation protocol. Mathematical models are often proposed to predict treatment outcome in this context, and have the potential to guide clinical decision-making and inform personalised fractionation protocols. Hindering effective use of models in this context is the sparsity of clinical measurements juxtaposed with the model complexity required to produce the full range of possible patient responses. In this work, we present a compartment model of tumour volume and tumour composition, which, despite relative simplicity, is …

Combining Spatially Fractionated Radiation Therapy (Sfrt) And Immunotherapy Opens New Rays Of Hope For Enhancing Therapeutic Ratio, Qiuxia Lu, Weisi Yan, Alan Zhu, Slavisa Tubin, Waleed F. Mourad, Jun Yang

Radiation Medicine Faculty Publications

Spatially Fractionated Radiation Therapy (SFRT) is a form of radiotherapy that delivers a single large dose of radiation within the target volume in a heterogeneous pattern with regions of peak dosage and regions of under dosage. SFRT types can be defined by how the heterogeneous pattern of radiation is obtained. Immune checkpoint inhibitors (ICIs) have been approved for various malignant tumors and are widely used to treat patients with metastatic cancer. The efficacy of ICI monotherapy is limited due to the “cold” tumor microenvironment. Fractionated radiotherapy can achieve higher doses per fraction to the target tumor, and induce immune activation …

Evidence Of Direct Interaction Between Cisplatin And The Caspase-Cleaved Prostate Apoptosis Response-4 Tumor Suppressor, Krishna K. Raut, Samjhana Pandey, Gyanendra Kharel, Steven M. Pascal

Chemistry & Biochemistry Faculty Publications

Prostate apoptosis response-4 (Par-4) tumor suppressor protein has gained attention as a potential therapeutic target owing to its unique ability to selectively induce apoptosis in cancer cells, sensitize them to chemotherapy and radiotherapy, and mitigate drug resistance. It has recently been reported that Par-4 interacts synergistically with cisplatin, a widely used anticancer drug. However, the mechanistic details underlying this relationship remain elusive. In this investigation, we employed an array of biophysical techniques, including circular dichroism spectroscopy, dynamic light scattering, and UV–vis absorption spectroscopy, to characterize the interaction between the active caspase-cleaved Par-4 (cl-Par-4) fragment and cisplatin. Additionally, elemental analysis was …

Developing Radiosensitizers To Enhance Radiotherapy In Treating Gastroenteropancreatic Neuroendocrine Tumor, Zeta Chow

Theses and Dissertations--Clinical and Translational Science

Gastroenteropancreatic Neuroendocrine Tumor (GEP-NET) is a heterogeneous group of malignancies arising from multipotent neuroendocrine stem cells in the gastrointestinal tract. The incidence of GEP-NET continues to rise, possibly due to the advancement of imaging and biomarkers available for diagnosis. However, even though the majority of patients are diagnosed with low-grade and localized disease, a significant percentage of patients present with advanced-stage metastatic disease with poor prognosis in months to a few years. These advanced-stage GEP-NET patients can also present with a variety of debilitating symptoms that significantly impact their quality of life. The role of palliative-intent surgery is limited, and …

Cbct Perceptions Of Radiology Leaders In The Midwest Dental Schools: A Qualitative Study, Tenzin Dadul

Dissertations

Problem

The integration of Cone Beam Computed Tomography (CBCT) in dental education is hindered by a lack of formal training among radiology leaders, insufficient institutional support, and financial constraints. Despite the proven efficacy of CBCT in enhancing diagnostic accuracy and treatment planning, its adoption in pre-doctoral curricula remains limited. This gap in education poses significant challenges for dental graduates, who are increasingly expected to utilize advanced imaging technologies in clinical practice.

Purpose of Study

This qualitative study aimed to explore the perceptions of radiology leaders in Midwest dental schools regarding the integration of CBCT education into pre-doctoral curricula. The objectives …

Reporting Quality Of Endoscopic Colorectal Cancer Screening Randomized Controlled Trials: Adherence To Recommendations And Interventions, Fouad Jaber, Khalid Ahmed, Osama Hamid, Willie Mohammed Johnson, Saqr Alsakarneh, Abubaker O Abdalla, Yazan Abboud, Mouhand Mohamed, Dushyant Singh Dahiya, Shifa Umar, Mohamed Abdallah, Mohammad Bilal, Aasma Shaukat

Faculty, Staff and Student Publications

BACKGROUND AND AIMS: In 2013, the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) steering group published recommendations to standardize reporting quality in randomized controlled trials (RCTs). We aim to assess adherence to SPIRIT reporting guidelines in RCTs on endoscopic colorectal cancer (CRC) screening and participants' adherence to trial protocols.

METHODS: We searched databases for RCTs evaluating flexible sigmoidoscopy or colonoscopy for CRC screening published in English language through September 2023. Each eligible study was evaluated using the 8 core SPIRIT statement areas, totaling 51 points. Each item received 1 point if it met the criteria and 0 points if …

A Look-Up-Table Development To Facilitate Ct Simulation Of Mr-Linac Treatment, Neil Hughes, Travis C Salzillo, Sastry Vedam, Tze Yee Lim, Xin Wang, He Wang, Mustefa Mohammedsaid, Clifton D Fuller, Jihong Wang, Jinzhong Yang

Faculty, Staff and Student Publications

While current MR-Linac (MRL) treatment workflows utilize a large table overlay during CT simulation to convert indexing between the two machines, we developed a look-up-table (LUT) as an alternative approach. After populating the LUT, index conversion factors were verified at three separate table locations. The resultant root-mean-square isocenter shifts on the MRL were 0.04/0.08 cm, 0.08/0.07 cm, and 0.09/0.08 cm with/without using the table overlay during simulation in the lateral, longitudinal, and vertical directions, respectively, which is within registration tolerance. Clinical implementation of the LUT has resulted in a more efficient MRL treatment workflow while maintaining accurate patient setup.

Clinical Acceptability Of Automatically Generated Lymph Node Levels And Structures Of Deglutition And Mastication For Head And Neck Radiation Therapy, Sean Maroongroge, Abdallah Sr Mohamed, Callistus Nguyen, Jean Guma De La Vega, Steven J Frank, Adam S Garden, Brandon G Gunn, Anna Lee, Lauren Mayo, Amy Moreno, William H Morrison, Jack Phan, Michael T Spiotto, Laurence E Court, Clifton D Fuller, David I Rosenthal, Tucker J Netherton

Faculty, Staff and Student Publications

BACKGROUND AND PURPOSE: Auto-contouring of complex anatomy in computed tomography (CT) scans is a highly anticipated solution to many problems in radiotherapy. In this study, artificial intelligence (AI)-based auto-contouring models were clinically validated for lymph node levels and structures of swallowing and chewing in the head and neck.

MATERIALS AND METHODS: CT scans of 145 head and neck radiotherapy patients were retrospectively curated. One cohort (n = 47) was used to analyze seven lymph node levels and the other (n = 98) used to analyze 17 swallowing and chewing structures. Separate nnUnet models were trained and validated using the separate …

Harnessing Uncertainty In Radiotherapy Auto-Segmentation Quality Assurance, Kareem A Wahid, Jaakko Sahlsten, Joel Jaskari, Michael J Dohopolski, Kimmo Kaski, Renjie He, Enrico Glerean, Benjamin H Kann, Antti Mäkitie, Clifton D Fuller, Mohamed A Naser, David Fuentes

Faculty, Staff and Student Publications

One of the key contributions of this study is the reappropriation of standard DL outputs as a quality indicator to identify cases that clinicians should review further. The authors achieve this by applying an empirically derived threshold to the softmax output of their DL network, computing the mean of the thresholded score map (termed the HiS metric), and correlating it with standard geometric quality indices. When juxtaposed with a mean entropy — a commonly used measure of model output uncertainty — HiS consistently demonstrated a stronger correlation with the geometric indices, suggesting its superior ability to stratify cases needing additional …

Optimal Dual-Time-Point Dynamic 68ga-Psma-11 Pet/Ct Protocols For Parametric Imaging Generation In Prostate Cancer Patients, Paphawarin Burasothikul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Globally, prostate cancer is the second most common cancer for men. Prostate cancer patients presenting metastasis exhibit a poor prognosis, consequently leading to diminished survival rates. Thus, 68Ga-PSMA-11 PET/CT examination plays a critical role in prostate cancer diagnosis. Parametric imaging techniques offer the potential to improve the accuracy of quantification analysis in PET/CT diagnosis, but their effectiveness is constrained by lengthy acquisition protocols. This study developed optimal dual-time-point (DTP) parametric imaging using shortened dynamic 68Ga-PSMA-11 PET/CT scans in prostate cancer patients and investigated the feasibility of parametric images in terms of image quality by comparing them with a routine standardized …

Prediction The Dose Distributions Of Prostate Cancer Patients Using Deep Learning, Pumipat Chaikamthorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Volumetric Modulated Arc Therapy (VMAT) is one of the advanced modalities in recent radiotherapy. It uses the inverse treatment planning system for optimization and dose calculation. However, this approach is a trial-and-error process, which takes a long time. An accurate deep-learning model that can predict the dose would solve this issue. This approach can save more treatment planning time, by guiding the planners to the optimum dose while maintaining the plan quality. The 40 previously treated prostate cancer plans were collected the volumetric information of PTV and OARs, overlapping volume, and the dosimetric information. The regression deep learning model, which …

Dosimetric Comparison Between Volumetric Modulated Arc Therapy On Truebeam And Halcyon Of Boost Plan For Total Body Irradiation, Wanwanut Jaihow

Chulalongkorn University Theses and Dissertations (Chula ETD)

Total Body Irradiation (TBI) is a special treatment technique aimed at immunosuppression. The purpose of this study was to compare the dosimetric results of volumetric modulated arc therapy (VMAT) plans of TBI treatment between TrueBeam and Halcyon treatment machines. Eight TBI patients were planned by 6 MV of two lateral opposing with extended SAD technique to 5 meters to receive the prescribed dose of 1200 cGy in 6 fractions at head and legs. A single fraction boosts up the dose ranging from shoulder to mid-thigh. Plans were optimized and calculated in the Eclipse treatment planning system using VMAT by TrueBeam …

Local Diagnostic Reference Level At Nuclear Medicine Centers In Thailand And Myanmar, Yin Moe Aye

Chulalongkorn University Theses and Dissertations (Chula ETD)

Diagnostic reference level (DRL) has been an effective and practical tool in the optimization of radiation protection in medical exposure to patients. Local DRL represents the median value, or 50th percentile, of the quantity distribution of common nuclear medicine examinations. This study aims to establish LDRL at NM centers in Thailand and Myanmar. Methods: The demographic data of adult patients with body weight 45-75kg, radiation metric parameters including radiopharmaceutical administered activity (MBq), Volumetric CT dose index (CTDIvol, mGy), dose length product (DLP, mGy. cm), and scan length (cm), of SPECT, SPECT/CT, and PET/CT imaging were retrospectively collected from January 2023 …

Evaluating Dosimetric Accuracy Of Aaa And Axb Algorithms In Lung Stereotactic Body Radiation Therapy, May Thu Htet

Chulalongkorn University Theses and Dissertations (Chula ETD)

The accuracy of dose calculation in heterogeneous media is heavily influenced by the choice of dose calculation algorithm. This study aimed to compare the dosimetric performance of the Anisotropic Analytical Algorithm (AAA) and Acuros XB (AXB) in stereotactic body radiotherapy (SBRT) for lung cancer. Twenty-four lung cancer patients were divided into two groups: free breathing (FB) and deep inspiration breath hold (DIBH). For each patient, three half-arc volumetric modulated arc therapy (VMAT) plans were generated using 6 MV flattening filter-free (FFF) beams, prescribing 50 Gy in five fractions to the planning target volume (PTV), using the Eclipse Treatment Planning System. …

Tumor Prognosis In Nasopharyngeal Carcinoma Using Deep Transfer Learning With Radimagenet From Ct Images, Parida Petiraksakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nasopharyngeal carcinoma (NPC) is a common malignant tumor in Southeast Asia. It is characterized by complex anatomical features and aggressive behavior. Accurate prognosis prediction plays a crucial role in the optimization of treatment strategies and improvement of patient outcomes. Although recent advances in deep learning, particularly convolutional neural networks (CNNs), have demonstrated promising results in medical image analysis, the limited availability of annotated medical imaging datasets remains a significant challenge. Transfer learning (TL), particularly using domain-specific pretrained datasets, such as RadImageNet, offers a practical solution to this limitation. This study aimed to evaluate the effectiveness of deep transfer learning models …

Mri-Based Radiomics Model From Mesorectal Fat To Predict Perirectal Lymph Node Status And Extramural Venous Invasion In Colorectal Cancer Patients, Yaniga Swaengdee

Chulalongkorn University Theses and Dissertations (Chula ETD)

Colorectal cancer (CRC) is the third most common cancer worldwide and the incidence rate is rising in Asia. Perirectal lymph node metastasis (PLN) and extramural venous invasion (EMVI) are common and associated with poor prognosis in CRC patients. While total mesorectal excision is the gold standard for confirming PLN and EMVI, MRI is keys modality for staging. Radiomics, a technique that extracts quantitative features from medical images, allows for the development of predictive models for PLN and EMVI. This study aimed to build and evaluate a predictive model based on mesorectal fat radiomics from MRI images to improve PLN and …

Varian Halcyon Cone Beam Computed Tomography Dose Measurement By Radiophotoluminescent Glass Dosimeter, Kantida Jittrakool

Chulalongkorn University Theses and Dissertations (Chula ETD)

Cone beam computed tomography (CBCT) is widely used as the primary imaging method in image-guided radiation therapy. The Varian Halcyon system (Varian Medical Systems, Palo Alto, CA, USA) requires daily imaging prior to each patient’s treatment. This study focuses on comparing the radiation doses to normal organs across all available kV-CBCT protocols on the Varian Halcyon system. Radiophotoluminescent glass dosimeters (RPLGD) were used to measure doses, placed inside an Alderson Rando phantom positioned at specific anatomical sites including the head, thorax, breast, and pelvis. CBCT scans were performed using preset protocols, with no modifications to parameters. The average organ dose …