A5090401347- Advanced Radiotherapy Techniques
- Medical Imaging Techniques and Applications
- Lung Cancer Diagnosis and Treatment
- Radiation Therapy and Dosimetry
- Management of metastatic bone disease
- Radiomics and Machine Learning in Medical Imaging
- Radiation Dose and Imaging
- Radiopharmaceutical Chemistry and Applications
- Brain Metastases and Treatment
- Advanced X-ray and CT Imaging
- Hepatocellular Carcinoma Treatment and Prognosis
- Digital Radiography and Breast Imaging
- Breast Cancer Treatment Studies
- Advances in Oncology and Radiotherapy
- Radiation Detection and Scintillator Technologies
- Medical Imaging and Analysis
- Lung Cancer Treatments and Mutations
- Spine and Intervertebral Disc Pathology
- Cancer Risks and Factors
- Head and Neck Cancer Studies
- Chemotherapy-induced cardiotoxicity and mitigation
- Glioma Diagnosis and Treatment
- Colorectal Cancer Treatments and Studies
- Nuclear Physics and Applications
- Cardiac Imaging and Diagnostics
University of British Columbia
2007-2025
University of Pennsylvania
2023
BC Cancer Agency
2011-2022
Spinal Cord Injury BC
2022
Vancouver Clinic
2008-2021
Kelowna General Hospital
2021
Royal North Shore Hospital
2015
The University of Sydney
2015
Montreal Neurological Institute and Hospital
1997-2002
McGill University
1997-2002
After the publication of landmark SABR-COMET trial, concerns arose regarding high-grade toxic effects treatment with stereotactic ablative body radiotherapy (SABR) for oligometastases.To document SABR in a large cohort from population-based, provincial cancer program.From November 2016 to July 2020, 381 patients across all 6 centers British Columbia were treated this single-arm, phase 2 trial oligometastatic or oligoprogressive disease. During period, only eligible receive these settings...
Purpose A Monte Carlo (MC) based QA process to validate the dynamic beam delivery accuracy for Varian RapidArc ™ (Varian Medical Systems, Palo Alto, CA) using Linac log files (DynaLog) is presented. Using DynaLog file analysis and MC simulations, goal of this article (a) confirm that adequate sampling used in optimization algorithm (177 static gantry angles) (b) assess physical machine performance [gantry angle monitor unit (MU) accuracy]. Methods Ten clinically acceptable treatment plans...
Interest is growing in treating multiple brain metastases with radiosurgery. We report on the effectiveness and tolerability of volumetric radiosurgery (VRS).We enrolled patients a ≥6-month estimated life expectancy 1 to 10 diameter ≤3 cm at 5 cancer centers. Volumetric was delivered fractions 98% target coverage, prescribed as 95% 50 Gy (47.5 fractions) no margin 40 (38 their 2-mm planning volumes, concurrent 20 whole volume. The treatment daily image guidance using conventional linear...
Breast/chest wall irradiation (RT) increases risk of cardiovascular death. International Quantitative Analysis Normal Tissue Effects in the Clinic (QUANTEC) guidelines state for partial heart a "V25Gy <10% will be associated with <1% probability cardiac mortality" long-term follow-up after RT. We assessed whether women treated breast/chest RT 10-years ago who died disease (CVD) violated QUANTEC guidelines.A population-based database identified all deaths early-stage breast cancer <80 years,...
To investigate the utility of implanted cardiac leads or diaphragm for active respiratory motion management in stereotactic arrhythmia radioablation (STAR) by quantifying relationship between their motions. Seven patients treated with STAR were imaged using 5 Hz bi-planar, kV x-ray fluoroscopy 15-20 seconds under both abdominal compression (AC) and free breathing (FB) conditions. 3D traces different regions heart acquired tracking triangulating position all leads. The heart's was extracted...
A Monte Carlo (MC) validation of the vendor‐supplied Varian TrueBeam 6 MV flattened (6X) phase‐space file and first implementation Siebers‐Keall MC MLC model as applied to HD120 (for 6X flat flattening filterfree (6X FFF) beams) are described. The is validated in context VMAT patient‐specific quality assurance. commissioning process involves: 1) validating calculated open‐field percentage depth doses (PDDs), profiles, output factors (OF), 2) adapting match new HD120‐MLC geometry material...
To commission and benchmark a vendor-supplied (Varian Medical Systems) Monte Carlo phase-space data for the 6 MV flattening filter free (FFF) energy mode on TrueBeam linear accelerator purpose of quality assurance clinical volumetric modulated arc therapy (VMAT) treatment plans. A method rendering compatible with BEAMnrc/DOSXYZnrc simulation software package is presented.Monte (MC) simulations were performed to FFF phase space that have been released by Varian MC Research team. The done in...
Performance characteristics of a positron emission mammographic (PEM) instrument were studied. This dedicated metabolic breast imaging system has spatial resolution 2.8-mm full width at half maximum (FWHM), coincidence resolving time 12-nsec FWHM, and absolute efficiency 3%. Hot spots with diameter 16 mm in phantom signal-to-background activity ratio 6:1 distinguishable scanning 5 minutes.
This work introduces an EGSnrc‐based Monte Carlo (MC) beamlet does distribution matrix into a direct aperture optimization (DAO) algorithm for IMRT inverse planning. The technique is referred to as Carlo–direct (MC‐DAO). goal assess if the combination of accurate tissue inhomogeneity modeling and DAO planning will improve dose accuracy treatment efficiency Several authors have shown that presence small fields and/or inhomogeneous materials in can cause calculation errors algorithms are...
Oligometastases refer to a state of disease where cancer has spread beyond the primary site, but is not yet widely metastatic, often defined as 1–3 or 1–5 metastases in number. Stereotactic ablative radiotherapy (SABR) an emerging technique treat oligometastases that require further prospective population-based toxicity estimates. This non-randomized phase II trial all participants will receive experimental SABR treatment sites newly diagnosed progressing oligometastatic disease. We accrue...
X-ray mammograms reveal abnormal tissue densities, while metabolic images identify regions of metabolism. Conventional nuclear medicine and radiologic breast must be acquired at different times with patient positions making coregistration difficult. Accurate x-ray the is likely to important when acquiring information about location diagnosis suspicious lesions or tumors. Our PEM-1 (positron emission mammography) system detects activity within breast. The two planar detectors are integrated...
Abstract Purpose To assess the feasibility of using diaphragm as a surrogate for liver targets during MDTT. Methods Diaphragm markers: dome‐shaped phantom with implanted markers was fabricated and underwent dual‐orthogonal fluoroscopy sequences on Vero4DRT linac. Ten patients participated in an IRB‐approved, study to MDTT workflow. All images were analyzed in‐house program back‐project diaphragm/markers position isocenter plane. ExacTrac imager log files analyzed. tracking structure MDTT:...
Crossed anode wire position sensitive photomultiplier tubes (PS-PMTs) detect the location of a light source and provide X Y axis coordinates event. These are typically generated using Anger logic, where resistor chain divides current flow into two signals for each coordinate (X/sup +/, X/sup -/ Y/sup -/). In standard readout, identical values used across entire chain. While this arrangement provides linear readout in central portion face, is non-linear sometimes even double valued near edges...
Abstract Introduction Dynamic tumor tracking (DTT) is a motion management technique where the radiation beam follows moving in real time. Not modelling DTT treatment planning system leaves an organ at risk (OAR) vulnerable to exceeding its dose limit. This work investigates two strategies for plans, “Boolean OAR Method” and “Aperture Sorting Method,” determine if they can successfully spare while maintaining sufficient target coverage. Materials methods A step‐and‐shoot intensity modulated...