A5072588832- Advanced Radiotherapy Techniques
- Medical Imaging Techniques and Applications
- Radiation Therapy and Dosimetry
- Advanced MRI Techniques and Applications
- Radiation Dose and Imaging
- Gamma-ray bursts and supernovae
- Radiation Detection and Scintillator Technologies
- Astro and Planetary Science
- Radiopharmaceutical Chemistry and Applications
- Brain Metastases and Treatment
- MRI in cancer diagnosis
- Radiation Effects in Electronics
- Analytical Chemistry and Sensors
- Conducting polymers and applications
- Advanced X-ray and CT Imaging
- Organic Electronics and Photovoltaics
- Colorectal and Anal Carcinomas
- Nuclear Physics and Applications
- Lanthanide and Transition Metal Complexes
- Metabolomics and Mass Spectrometry Studies
- Glioma Diagnosis and Treatment
- Solar and Space Plasma Dynamics
- Hepatocellular Carcinoma Treatment and Prognosis
- Radiation Effects and Dosimetry
- Lung Cancer Diagnosis and Treatment
Nova Scotia Health Authority
2017-2025
Dalhousie University
2016-2025
Queen Elizabeth II Health Sciences Centre
2016-2025
Health Sciences Centre
2016-2023
Beatrice Hunter Cancer Research Institute
2021-2022
McGill University
2012-2017
Jewish General Hospital
2013-2017
Nova Scotia Cancer Centre
2016
University of Alberta
2003-2015
Alberta Health Services
2010
A new role for the multifunctional protein CTCF in repair of DNA double-strand breaks is discovered.
A stemless plastic scintillation detector (SPSD) is composed of an organic scintillator coupled to photodiode. Previous research has shown that SPSDs are ideally suited challenging dosimetry measurements such as output factors and profiles in small fields. Lacking from the current literature a systematic effort optimize performance photodiode component detector. An optimized could permit reduction element size, thus improving spatial resolution without degradation signal noise ratio values...
Abstract intra‐arc binary collimation (iABC) is a novel treatment technique in which dynamic conformal arcs are periodically interrupted with collimation. It has demonstrated its utility through planning studies for the of multiple metastases. However, approach idealized system, while deliveries must adhere to physical limitations mechanical systems involved [e.g., multi‐leaf (MLC) leaf speed]. This work focuses on optimizing delivery collimation‐based stereotactic radiosurgery/radiotherapy...
To perform precision dosimetry in yttrium-90 radioembolization through CT imaging of radiopaque microspheres a rabbit liver model and to compare extracted dose metrics those produced from conventional PET-based dosimetry.A calibration phantom was designed containing posts with nominal microsphere concentrations 0.5 mg/mL, 5.0 25.0 mg/mL. The mean Hounsfield unit the post volumes generate curve relate units concentration. A bolus 40 mg administered livers eight rabbits, followed by PET/CT...
Existing studies have suggested some debate on whether the quality of radiation that delivers dose outside primary field a radiotherapy photon beam can be considered same as inside field. We used Monte Carlo approach to simulate electron fluence differential in energy water phantom response irradiation by 6 MV beam. The goal was quantify how significantly changes when moving from volume exposed one field, and understand any potential biological implications. scored outwards annular volumes 5...
We performed two‐dimensional treatment verifications for ten patients planned and treated with helical tomotherapy. The verification consisted of a film measurement as well point dose measurements made an ion chamber. agreement between the calculated measured distributions was evaluated gamma index three sets criteria (2 mm 2%, 4 3%, 3 5%) recommended in literature. Good found without any need normalization data but map registration using reference marks. In this case, , passed 2 5%...
Reproducible positioning of the patient during fractionated external beam radiation therapy is imperative to ensure that delivered dose distribution matches planned one. In this paper, we expand on a 2D‐3D image registration method verify patient's setup in three dimensions (rotations and translations) using orthogonal portal images megavoltage digitally reconstructed radiographs (MDRRs) derived from CT data. The accuracy was improved by employing additional preprocessing steps parabolic fit...
Scattered radiation in the penumbra of a megavoltage therapy beam can deposit non-negligible dose healthy tissue around target volume. The lower energy this region suggests that its biological effectiveness might not be same as open beam. In work, we determined relative damage normal human fibroblasts after irradiation two geometries. first was an open-beam and second blocked configuration which only scattered could reach cells. evaluated by gamma-H2AX immunofluorescence assay, is capable...
The generation of a self-resolved radiation-induced oral mucositis (RIOM) mouse model using the highest possibly tolerable single ionizing radiation (RT) dose was needed in order to study RIOM management solutions. We used 10 week-old male BALB/c mice with average weight 23 gm for production. Mice were treated an orthovoltage X-ray irradiator induce ulceration at intermolar eminence animal tongue. General anesthesia injected intraperitoneally proper immobilization during procedure. days...
The 4π methodology determines optimized noncoplanar subarcs for stereotactic radiation therapy that minimize dose to organs-at-risk. Every combination of treatment angle is examined, but some angles are not appropriate as a collision would occur between the gantry and couch or patient. Those combinations referred zones. A major barrier applying body (SBRT) unknown shape zones, which significant patients take up large volume within sphere. This study presents system patient-specific without...
Purpose To develop an algorithm for dynamic collimator positioning to optimize beam's eye view ( BEV ) fitting of targets in conformal arc DCA )‐based radiotherapy procedures, particular use multiple metastases stereotactic radiosurgery procedures. Methods A trajectory was developed dynamically modify the angle as a function arc‐based control point provide optimized collimation target volume(s). Central this is concept denoted herein “whitespace” defined any nontarget area that not covered...
Purpose To develop a novel system for patient‐specific combined optimization of couch, collimator, and gantry angles use in volumetric modulated arc therapy (VMAT) treatment planning. The was designed to produce highly compact dose distributions by extensively sampling the 4π space. Automated fixed couch trajectory planning used reduce normal tissue doses avoiding beams‐eye‐view (BEV) overlap with organs‐at‐risk (OARs) improve monitor unit (MU) efficiency through collimator angle...
This study aimed to investigate intra- and interfraction motion during liver stereotactic body radiation therapy for the purpose of planning target volume (PTV) margin estimation, comparing deep inspiration breath hold (DIBH) expiration (DEBH).Pre- posttreatment kV cone beam computed tomography (CT) images were acquired patients with cancer who treated using DIBH or DEBH. A total 188 analyzed from 18 patients. Positioning errors determined based on a comparison CT matching liver. Treatment...
Single event spectra for five beta-emitting radionuclides (Lu-177, Cu-67, Re-186, Re-188, Y-90) were calculated single cells from two source geometries. The first was a surface-bound isotropically emitting point and the second bath of free radioactivity in which cell submerged. Together these represent targeted intraperitoneal radionuclide therapy. Monoenergetic over an energy range 11 keV to 2500 using EGSnrc Monte Carlo system. Radionuclide constructed by weighting monoenergetic according...
The purpose of this study is to use magnetic resonance imaging monitor the response human glioma tumor xenografts single fraction radiation therapy. Mice were divided into four treatment groups ( per group) that received 50, 200, 400, or 800 cGy 200 kVp x rays. A fifth group no dose and served as control. Quantitative maps treated tissue produced water apparent diffusion coefficient (ADC) transverse relaxation time (T2). imaged before at multiple points after treatment. There was a...
Objective. Non-coplanar arc geometry optimizations that take advantage of beam's eye view (BEV) geometric overlap information have been proven to reduce dose healthy organs-at-risk (OARs). Recently, a metric called mean distance (MAD) has developed quantifies the sampling 4πspace. The purpose this research is combine improved BEV with MAD generate static couch lung stereotactic body radiotherapy (SBRT) treatment plans deliverable on C-arm linear accelerator.Approach. An algorithm utilizing...
Abstract Noncoplanar arc optimization has been shown to reduce OAR doses in SRS/SRT and the potential OARs SBRT. Extracranial targets have additional considerations, including large and, case of liver, volume constraints on healthy liver. Considering pathlengths through that encompass target volumes may lead specific dose reductions as encompassing liver tissue. These optimizations must also leverage delivery efficiency trajectory sampling ensure ease clinical translation. The purpose this...
Abstract Purpose To investigate the possible advantages of using 4pi‐optimized arc trajectories in stereotactic body radiation therapy ventricular tachycardia (VT‐SBRT) to minimize exposure healthy tissues. Methods and materials Thorax computed tomography (CT) data for 15 patients were used contouring organs at risk (OARs) defining realistic planning target volumes (PTVs). A conventional trajectory plan, defined as two full coplanar arcs was compared an optimized‐trajectory plan provided by...
The purpose of this study is to investigate the response transverse relaxation time (T2) and apparent diffusion coefficient (ADC) in human glioma tumor xenografts during after fractionated radiotherapy. Tumor-bearing mice were divided into four treatment groups (n = 6 per group) that received a total dose 800 cGy 200 kVp x-rays, given over two or three fractions, with fraction spacing either 24 72 h. A fifth group single fraction, sixth served as an untreated control. All scanned...
Purpose Magnetic resonance imaging was used to compare the responses of human glioma tumor xenografts a single fraction radiation, where change in radiosensitivity induced by use suture‐based ligature. Methods Ischemia Six mice were treated with 800 cGy 200 kVp x rays while ligature applied. An additional six had applied for same length time but not irradiated. Quantitative maps each produced water apparent diffusion coefficient (ADC) and transverse relaxation (T2). Mice imaged before at...