A5073447045- Advanced Radiotherapy Techniques
- Medical Imaging Techniques and Applications
- Radiation Therapy and Dosimetry
- Glioma Diagnosis and Treatment
- Radiation Effects and Dosimetry
- Brain Metastases and Treatment
- Radiation Dose and Imaging
- Liquid Crystal Research Advancements
- Molecular spectroscopy and chirality
- Management of metastatic bone disease
- Effects of Radiation Exposure
- Meningioma and schwannoma management
- Advanced X-ray and CT Imaging
- Radiomics and Machine Learning in Medical Imaging
- Brain Tumor Detection and Classification
- Breast Cancer Treatment Studies
- Radiopharmaceutical Chemistry and Applications
- Lung Cancer Diagnosis and Treatment
- Advanced MRI Techniques and Applications
- Advances in Oncology and Radiotherapy
- Nonlinear Dynamics and Pattern Formation
- Radiation Detection and Scintillator Technologies
- Endometrial and Cervical Cancer Treatments
- MRI in cancer diagnosis
- Plant Reproductive Biology
The University of Texas Southwestern Medical Center
2015-2024
Southwestern Medical Center
2013-2024
Urology San Antonio
2021
UnityPoint Health
2021
Neurological Surgery
2021
Baylor Scott & White Health
2021
Radiation Oncology Associates
2009-2017
Pontificia Universidad Católica de Chile
2016
University Hospital of Zurich
2013
Virginia Commonwealth University
2007-2008
Accurate and automatic brain metastases target delineation is a key step for efficient effective stereotactic radiosurgery (SRS) treatment planning. In this work, we developed deep learning convolutional neural network (CNN) algorithm segmenting on contrast-enhanced T1-weighted magnetic resonance imaging (MRI) datasets. We integrated the CNN-based into an segmentation workflow validated both Multimodal Brain Tumor Image Segmentation challenge (BRATS) data clinical patients' data. Validation...
Purpose To examine the potential use of blood oxygenation level dependent (BOLD) and tissue (TOLD) contrast MRI to assess tumor predict radiation response. Methods BOLD TOLD were performed on Dunning R3327-AT1 rat prostate tumors during hyperoxic gas breathing challenge at 4.7 T. Animals divided into two groups. In Group 1 (n = 9), subsequent 19F based spin lattice relaxation hexafluorobenzene reporter molecule provided quantitative oximetry for comparison. For 2 rats 13) growth delay...
Radiation dose is central to much of radiobiological research. Precision and accuracy measurements reporting the measurement details should be sufficient allow work interpreted repeated valid comparisons made, both in same laboratory by other laboratories. Despite this, a careful reading published manuscripts suggests that radiation dosimetry setup for radiobiology research frequently inadequate, thus undermining reliability reproducibility findings. To address these problems propose course...
A novel small animal conformal radiation therapy system has been designed and prototyped: MicroRT. The microRT integrates multimodality imaging, treatment planning, that utilizes a clinical isotope high dose rate source as the (teletherapy). multiparameter calculation algorithm based on Monte Carlo distribution simulations is used to efficiently accurately calculate doses for planning purposes. series of precisely machined tungsten collimators mounted onto cylindrical collimator assembly...
Small animal irradiation provides an important tool used by preclinical studies to assess and optimize new treatment strategies such as stereotactic ablative radiotherapy. Characterization of radiation beams that are clinically geometrically scaled for the small model is uniquely challenging orthovoltage energies minute field sizes. The irradiator employs a commercial x-ray device (XRAD 320, Precision x-ray, Inc.) with custom collimation system produce 1-10 mm diameter 50 reference beam....
The dielectric fluctuations in the uniaxial nematic phase of a bent-core liquid crystal have been studied by dynamic light scattering. Polarization selection scattering cross-section reveals one mode due to ordinary director and, lower part phase, second attributable biaxial order parameter. are approximately 100 times slower than observed typical nematics based on straight-core molecules, suggesting that bent core nematogenic units may be microscopic smectic domains ("cybotactic" clusters).
Magnetic birefringence and dynamic light scattering measurements of orientational order parameter fluctuations at the isotropic-nematic phase transition a bent-core liquid crystal reveal pretransitional temperature dependence consistent with standard Landau--deGennes mean field theory. However, as follows: in compound is more weakly first $({T}_{NI}\ensuremath{-}{T}^{*}\ensuremath{\approx}0.4\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C})$, leading Landau...
Agreement between planned and delivered dose distributions for patient-specific quality assurance in routine clinical practice is predominantly assessed utilizing the gamma index method. Several reports, however, fundamentally question current IMRT QA due to poor sensitivity specificity of standard implementation. An alternative employ volume histogram (DVH)-based metrics. analysis based on AAPM TG 53 ESTRO booklet No.7 recommendations treatment planning systems reveals deficiencies "state...
Various optical and dynamic light scattering studies have been conducted on the nematic phase of an oxazole-derived bent-core liquid crystal. At length scales in absence applied fields, homogeneously aligned samples this material, which has oxazole heterocyclic ring central core, are found to behave more like a conventional straight-core than previously investigated ester-based class molecules that benzene as core linkage between two arms bow-shaped molecule. In particular, refractive...
Radiation therapy is a primary treatment for non-resectable lung cancer and hypoxia thought to influence tumor response. Hypoxia expected be particularly relevant the evolving new radiation scheme of hypofractionated stereotactic body (SBRT). As such, we sought develop non-invasive tools assess pathophysiology response irradiation. We applied blood oxygen level dependent (BOLD) tissue (TOLD) MRI, together with dynamic contrast enhanced (DCE) MRI explore longitudinal effects SBRT on...
Background Ionizing radiation is genotoxic to cells. Healthy tissue toxicity in patients and resistance tumors present common clinical challenges delivering effective therapies. Radiation response a complex, polygenic trait with unknown genetic determinants. The Drosophila Genetic Reference Panel (DGRP) provides model investigate the genetics of natural variation for sensitivity radiation. Methods Findings was quantified 154 inbred DGRP lines, among which 92 radiosensitive lines 62...
Detection and segmentation of brain metastases (BMs) play a pivotal role in diagnosis, treatment planning, follow-up evaluations for effective BM management. Given the rising prevalence cases its predominantly multiple onsets, automated is becoming necessary stereotactic radiosurgery. It not only alleviates clinician’s manual workload improves clinical workflow efficiency but also ensures safety, ultimately improving patient care. Recent strides machine learning, particularly deep learning...
Microradiation therapy (microRT) systems are being designed to provide conformal radiation small animals enabling quantitative response evaluation. We used a Monte Carlo approach estimate the dose distributions from proposed blueprints and developed beam model aid in microRT system design process. This process was applied prototype irradiator that uses (3 mm long 3 diameter), cylindrical, high-activity 192Ir source delivering using custom-fabricated tungsten collimators. The BEAMnrc code...
An x-ray image-guided small animal stereotactic irradiator was developed and characterized to enable tumor visualization accurate target localization for field, high dose irradiation. The system utilizes a custom collimation system, motorized positioning (x, y, θ), digital imaging panel operating software, is integrated with commercial unit. essential characteristics of the include radiation fields (1-10 mm), rate (>10 Gy min(-1)) submillimeter localization. software enables...
The aim of this study is to compare the recent Eclipse Acuros XB (AXB) dose calculation engine with Pinnacle collapsed cone convolution/superposition (CCC) algorithm and anisotropic analytic (AAA) for stereotactic ablative radiotherapy (SAbR) treatment planning thoracic spinal (T-spine) metastases using IMRT VMAT delivery techniques. three commissioned engines (CCC, AAA, AXB) were validated ion chamber EBT2 film measurements utilizing a heterogeneous slab-geometry water phantom an...
The objective of this study is to develop an automatic segmentation strategy for efficient and accurate metastatic brain tumor delineation on contrast-enhanced T1-weighted (T1c) magnetic resonance images (MRI) stereotactic radiosurgery (SRS) applications. proposed four-step metastases comprised pre-processing, initial contouring, contour evolution, triage. First, T1c are preprocessed remove the skull. Second, created using a multi-scaled adaptive threshold-based bounding box super-voxel...
We found that the optically isotropic (I(M)) mesophase observed recently below nematic phase of bent-core liquid crystal 4-chlororesorcinol bis[4-(4-n-dodecyloxybenzoyloxy)benzoate] shows ferroelectric-type switching. Polarizing microscopic, electric current, dielectric, and dynamic light scattering studies lead us to propose I(M) is composed interconnected orthoconic racemic smectic (Sm-Ca P(F)) nanodomains with random layer orientations. Near phase, where polarization can be saturated by...
Purpose : To develop and validate methods for small‐animal CNS radiotherapy using the microRT system. Materials Methods A custom head immobilizer was designed built to integrate with a pre‐existing animal couch. The Delrin ® couch‐immobilizer assembly, compatible multiple imaging modalities (CT, microCT, microMR, microPET, microSPECT, optical), first imaged via CT in order verify safety reproducibility of immobilization method. Once verified, subject animals were CT‐scanned while positioned...
High dose rate (HDR) brachytherapy treatment planning is conventionally performed manually and/or with aids of preplanned templates. In general, the standard care would be elevated by conducting an automated process to improve efficiency, eliminate human error, and reduce plan quality variations. Thus, our group developing AutoBrachy, HDR suite modules used augment a clinical system. This paper describes proof-of-concept module for vaginal cylinder that has been fully developed. After...