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- Adaptive design (1)
- Bayesian adaptive randomization (1)
- Biological modeling (1)
- Biological optimization (1)
- Carbon RBE (1)
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- Carbon radiotherapy (1)
- Enrichment strategy (1)
- Image variability (1)
- Information theory (1)
- Micro-cube (1)
- Microdosimetric uncertainty (1)
- Microdosimetry (1)
- Monte carlo simulation (1)
- Mutual information (1)
- Optimization (1)
- Proton therapy (1)
- Quality assurance (1)
- Quantitative MRI (1)
- RBE measurement (1)
- Radiotherapy (1)
- Relative biological effectiveness (1)
- Small field dosimetry (1)
- TEPC uncertainty (1)
- TLD (1)
- Thermoluminescent dosimeter (1)
- Umbrella trials (1)
Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
A Signature Enrichment Design With Bayesian Adaptive Randomization For Cancer Clinical Trials, Fang Xia
A Signature Enrichment Design With Bayesian Adaptive Randomization For Cancer Clinical Trials, Fang Xia
Dissertations & Theses (Open Access)
Clinical trials in the era of precision medicine demand more flexible and efficient trial designs. Adaptive clinical trial designs allow pre-specified modifications of an on-going clinical trial and could shorten the trial duration. We reviewed five common types of adaptive clinical trials based on adaptation methods. In particular, outcome-randomization becomes more popular as it can assign more patients to the promising treatments based on the accumulated trial data. This data-driven allocation allows more patients to benefit from the trial, which is especially important for cancer patients. We compared different Bayesian outcome-adaptive randomization methods and discussed them from both methodological and …
Modeling Proton Relative Biological Effectiveness Using Monte Carlo Simulations Of Microdosimetry, Mark A. Newpower
Modeling Proton Relative Biological Effectiveness Using Monte Carlo Simulations Of Microdosimetry, Mark A. Newpower
Dissertations & Theses (Open Access)
Proton therapy is a radiotherapy modality that can offer a better physical dose distribution when compared to photon radiotherapy by taking advantage of the Bragg peak, a narrow region of rapid energy loss. Proton therapy is also known to offer an enhanced relative biological effectiveness (RBE) compared to photons. In the current clinical standard, RBE is fixed at 1.1 at all points along the proton beam, meaning protons are assumed to require 10% less dose than photons to achieve target coverage and organ at risk (OAR) sparing. However, there is mounting clinical evidence, and a significant number of in vitro …
Quantifying Uncertainty In A Measurement-Based Assessment Of Relative Biological Effectiveness In Carbon Ion Radiotherapy, Shannon Hartzell
Quantifying Uncertainty In A Measurement-Based Assessment Of Relative Biological Effectiveness In Carbon Ion Radiotherapy, Shannon Hartzell
Dissertations & Theses (Open Access)
One of the largest inconsistencies in dose delivered during carbon ion therapy is due to uncertainties in relative biological effectiveness (RBE), a value that is calculated via one of several clinically implemented algorithms. This study investigates the uncertainty in measured microdosimetric parameters for RBE calculation by the Microdosimetric Kinetic Model (MKM), Repair Misrepair Fixation model (RMF), and Local Effect Model I (LEM) using a Tissue Equivalent Proportional Counter (TEPC).
Microdosimetric spectra, kinetic energy spectra, and dose fragment contributions were calculated using Monte Carlo (GEANT IV) for monoenergetic and SOBP carbon beams of clinical energy. From microdosimetric spectra, lineal energy values …
Commissioning Of Micro-Cube Thermoluminescent Dosimeters For Small Field Dosimetry Quality Assurance In Radiotherapy, Brandon Luckett
Commissioning Of Micro-Cube Thermoluminescent Dosimeters For Small Field Dosimetry Quality Assurance In Radiotherapy, Brandon Luckett
Dissertations & Theses (Open Access)
Small field dosimetry presents complications and uncertainties that could be circumvented by using detectors which are smaller than the radiation field. This study evaluates the reproducibility and accuracy of TLD micro-cubes for use in stereotactic radiosurgery (SRS) remote auditing quality assurance (QA) for treatment centers participating in clinical trials. This study tested the hypothesis that TLD micro-cubes could be commissioned to evaluate small field dosimetry, and provide reproducibility within 3%, as well as assure agreement between measured dose and calculated doses to within 5%.
The aims of this thesis were to characterize and commission TLD micro-cubes as well as to …
An Information Theory Model For Optimizing Quantitative Magnetic Resonance Imaging Acquisitions, Drew Mitchell
An Information Theory Model For Optimizing Quantitative Magnetic Resonance Imaging Acquisitions, Drew Mitchell
Dissertations & Theses (Open Access)
Quantitative magnetic resonance imaging (qMRI) is a powerful group of imaging techniques with a growing number of clinical applications, including synthetic image generation in post-processing, automatic segmentation, and diagnosis of disease from quantitative parameter values. Currently, acquisition parameter selection is performed empirically for quantitative MRI. Tuning parameters for different scan times, tissues, and resolutions requires some measure of trial and error. There is an opportunity to quantitatively optimize these acquisition parameters in order to maximize image quality and the reliability of the previously mentioned methods which follow image acquisition.
The objective of this work is to introduce and evaluate a …