A5045013896- Advanced Radiotherapy Techniques
- Medical Imaging Techniques and Applications
- Lung Cancer Diagnosis and Treatment
- Radiomics and Machine Learning in Medical Imaging
- Advanced X-ray and CT Imaging
- Advanced MRI Techniques and Applications
- Radiation Dose and Imaging
- Global Cancer Incidence and Screening
- Radiation Therapy and Dosimetry
- Ultrasound and Hyperthermia Applications
- Ultrasound in Clinical Applications
- Colorectal Cancer Screening and Detection
- Lung Cancer Treatments and Mutations
- Atomic and Subatomic Physics Research
- Management of metastatic bone disease
- Hepatocellular Carcinoma Treatment and Prognosis
- Spine and Intervertebral Disc Pathology
- Urinary and Genital Oncology Studies
- Colorectal and Anal Carcinomas
- Effects of Radiation Exposure
- Bone Tumor Diagnosis and Treatments
- Esophageal Cancer Research and Treatment
- Artificial Intelligence in Healthcare and Education
- Nutrition, Genetics, and Disease
- Economic and Financial Impacts of Cancer
University of California, Los Angeles
2016-2025
Los Angeles Medical Center
2018
UCLA Health
2016
Cancer Council Australia
2011
University College Dublin
1993
Charing Cross Hospital
1965-1973
The Cathetron is a high dose-rate, remotely controlled, "afterloading" intracavitary radiation unit. prototype unit installed at the Charing Cross Group of Hospitals and clinical technique evolved for treatment uterine carcinoma using this machine are described.
Objective: To evaluate variations in intra- and interfractional tumour motion, the effect on internal target volume (ITV) contour accuracy, using deformable image registration of real-time two-dimensional-sagittal cine-mode MRI acquired during lung stereotactic body radiation therapy (SBRT) treatments. Methods: Five patients underwent free-breathing SBRT treatments ViewRay system, with dose prescribed to a planning (defined as 3–6 mm expansion 4DCT-ITV). Sagittal slice cine-MR images (3.5 ×...
Background/Objectives: 5DCT was first proposed in 2005 as a motion-compensated CT simulation approach for radiotherapy treatment planning to avoid sorting artifacts that arise 4DCT when patients breathe irregularly. Since March 2019, has been clinically implemented routine use at our institution leverage this technological advantage. The clinical workflow includes quality assurance report describes the output of primary steps. This study reports on challenges and using these reports....
Perflubron emulsion is a bromine-based particulate contrast agent that taken up selectively by the liver and spleen after IV injection. It does not leave vascular space also persists in blood for longer period than iodinated agents do. We performed preliminary study to determine value of perflubron as material CT sonography.To safety dose response an sonography, 18 cancer patients, 14 whom had hepatic metastases, were given 0.5-3.0 ml/kg emulsion. Sonography before immediately infusion then...
The aim of this study was to analyze the patterns prostate bed (PB) recurrence in cancer patients experiencing prostate-specific antigen (PSA) persistence (BCP) or biochemical (BCR) after radical prostatectomy using <sup>68</sup>Ga-PSMA-11 PET/CT (<sup>68</sup>Ga-PSMA PET) relation Radiation Therapy Oncology Group (RTOG) clinical target volumes (CTVs). <b>Methods:</b> This single-center, retrospective analysis included with BCP BCR and PB on <sup>68</sup>Ga-PSMA PET. recurrences were...
Although the effect of radiotherapy on small vessels, especially in skin, is well known, there are few reports damage to large arteries. Only doses excess skin tolerance normally cause notable anatomical changes (Ellinger, 1957), and Kinmonth, Rob Simeone (1962) state that several occasions they have seen a major arterial occlusion some years after heavy dose irradiation. Heidenberg, Lupowitch Tan (1966) reported subclavian arteries irradiation for Hodgkin's disease 21-year-old woman,...
Abstract Purpose Magnetic resonance image ( MRI ) guided radiotherapy enables gating directly on the target position. We present an evaluation of ‐guided system's performance using ‐compatible respiratory motion phantom and radiochromic film. Our is geared toward validation our institution's clinical protocol which involves planning to a volume formed by expanding 5 mm about gross tumor GTV based 3 window . Methods The consisted rod containing high‐contrast inserts moved in superior‐inferior...
The treatment of patients with uterine carcinoma high intensity radiation sources is described. clinical and biological features affecting the response to at these levels are discussed, compared similar treatments low dose-rates (the standard radium technique Charing Cross Group Hospitals). Observations on methods used recorded. regime described immediate effects noted.
Abstract Purpose/Objective Field size limitations on Halcyon and Ethos treatment machines largely preclude use of the conventional monoisocentric three‐field technique for breast/chest wall regional lymph nodes. We present an alternative, IMRT‐based planning approach that facilitates while preserving plan quality. Materials/Methods Eight breast node cases (four left‐sided, four right‐sided) were planned machine using a 15–17 field IMRT technique. Institutional quality metrics CTV PTV...
Abstract Objective . To combat the motion artifacts present in traditional 4D-CBCT reconstruction, an iterative technique known as motion-compensated simultaneous algebraic reconstruction (MC-SART) was previously developed. MC-SART employs a to obtain initial model, which suffers from lack of sufficient projections each bin. The purpose this study is demonstrate feasibility introducing model acquired during CT simulation MC-SART, coined model-based CBCT (MB-CBCT). Approach For 5 patients, we...
4D cone beam computed tomography (CBCT) images of the thorax and abdomen can have reduced quality due to limited number projections per respiratory bin used in gated image reconstruction. In this work, we present a new algorithm reconstruct high CBCT by simultaneously reconstructing generating an associated motion model. This is done updating model parameters compensate for during iterative reconstruction process. acquisition was simulated using digital eXternal CArdiac Torso (XCAT) phantom,...
Purpose To develop and evaluate a method of reconstructing patient‐ treatment day‐ specific volumetric image motion model from free‐breathing cone‐beam projections respiratory surrogate measurements. This Motion‐Compensated Simultaneous Algebraic Reconstruction Technique (MC‐SART) generates uses derived directly the projections, without requiring prior measurements 4DCT, can compensate for both inter‐ intrabin deformations. The be used to generate images at arbitrary breathing points, which...
The commercial 0.35-T magnetic resonance imaging (MRI)-guided radiotherapy vendor ViewRay recently introduced upgraded real-time frame rates based on compressed sensing techniques. Furthermore, additional motion tracking algorithms were made available. Compressed allows for increased image but may compromise quality. To assess the impact of this upgrade respiratory gating accuracy, we evaluated gated dose distributions pre- and post-upgrade using a phantom radiochromic film.Seven waveforms...
Abstract Background Lung computed tomography (CT) scan image registration is being used for lung function analysis such as ventilation. Given the high sensitivity of functional analyses to errors, an error scoring tool that can measure submillimeter errors needed. Purpose To propose tool, termed λ, whose spatial be quantify in steep gradient regions under realistic noise conditions. Methods λ compares two images, reference and evaluated. The HU distance scales both images are normalized by...
To demonstrate that a "5DCT" technique which utilizes fast helical acquisition yields the same respiratory-gated images as commercial for regular, mechanically produced breathing cycles.Respiratory-gated of an anesthetized, ventilated pig were generated using Siemens low-pitch protocol and 5DCT range rates amplitudes with standard low dose imaging protocols. reconstructions independently evaluated by measuring distances between tissue positions predicted 5D motion model those measured...
Purpose Lung diseases are commonly associated with changes in lung tissue's biomechanical properties. Functional imaging techniques, such as elastography, have shown great promise measuring properties, which could expand the utility and effectiveness of radiotherapy treatment planning. We present a novel methodology for characterizing key property, parenchymal elasticity, derived solely from 4DCT datasets. Methods Specifically, end‐inhalation end‐exhalation breathing phases datasets were...
Purpose: To determine if and by how much the commercial 4DCT protocols under‐ overestimate tumor breathing motion. Methods: 1D simulations were conducted that modeled a 16‐slice CT scanner tumors moving proportionally to amplitude. External surrogate traces of at least 5‐min duration for 50 patients used. Breathing trace amplitudes converted motion relating nominal 90th percentile amplitude, reflecting defined more recent 5DCT approach. Based on clinical low‐pitch helical acquisition,...
Lung tissue elasticity is an effective spatial representation for Chronic Obstructive Pulmonary Disease phenotypes and pathophysiology. We investigated a novel imaging biomarker based on the voxel-by-voxel distribution of lung elasticity. Our approach combines biomechanical modeling to characterize elasticity.We acquired 4DCT images 13 cancer patients with known COPD diagnoses GOLD 2017 criteria. Deformation vector fields (DVFs) from deformable registration end-inhalation end-exhalation...