A5013292433- Advanced Radiotherapy Techniques
- Radiation Therapy and Dosimetry
- Radiation Dose and Imaging
- Radiation Detection and Scintillator Technologies
- Medical Imaging Techniques and Applications
- Radiation Effects and Dosimetry
- Advanced X-ray and CT Imaging
- Radiomics and Machine Learning in Medical Imaging
- Nuclear Physics and Applications
- Lung Cancer Diagnosis and Treatment
- Effects of Radiation Exposure
- Radiation Shielding Materials Analysis
- Digital Radiography and Breast Imaging
- Bladder and Urothelial Cancer Treatments
- Advances in Oncology and Radiotherapy
- Advanced Glycation End Products research
- Cancer Immunotherapy and Biomarkers
- Head and Neck Cancer Studies
- Luminescence Properties of Advanced Materials
- Nuclear reactor physics and engineering
- Mesenchymal stem cell research
- thermodynamics and calorimetric analyses
- Ultrasound and Hyperthermia Applications
- AI in cancer detection
- DNA Repair Mechanisms
McGill University
2015-2025
University of Toronto
2016-2025
Princess Margaret Cancer Centre
2023-2025
University Health Network
2023-2025
KU Leuven
2025
McGill University Health Centre
2012-2023
Montreal General Hospital
2009-2022
Johns Hopkins University
2020
Ashland (United States)
2012-2020
UPMC Health System
2020
The American Association of Physicists in Medicine (AAPM) presents a new protocol, developed by the Radiation Therapy Committee Task Group 61, for reference dosimetry low‐ and medium‐energy x rays radiotherapy radiobiology It is based on ionization chambers calibrated air terms kerma. If point interest at or close to surface, one unified approach over entire energy range shall be used determine absorbed dose water surface phantom an in‐air measurement (the “in‐air” method). depth, in‐water...
In this study, a measurement protocol is presented that improves the precision of dose measurements using flat-bed document scanner in conjunction with two new GafChromic® film models, HS and Prototype A EBT exposed to photon beams. We established sources uncertainties measurements, governed by calibration curve fit parameters contributions. have quantitatively assessed influence different steps on overall uncertainty. Applying described paper Agfa Arcus II scanner, one-sigma uncertainty for...
The use of small fields in radiotherapy techniques has increased substantially, particular stereotactic treatments and large uniform or nonuniform that are composed such as for intensity modulated radiation therapy (IMRT). This been facilitated by the availability standard add‐on multileaf collimators a variety new treatment units. For these fields, dosimetric errors have become considerably larger than conventional beams mostly due to two reasons; (i) reference conditions recommended Codes...
Quantitative extraction of high-dimensional mineable data from medical images is a process known as radiomics. Radiomics foreseen an essential prognostic tool for cancer risk assessment and the quantification intratumoural heterogeneity. In this work, 1615 radiomic features (quantifying tumour image intensity, shape, texture) extracted pre-treatment FDG-PET CT 300 patients four different cohorts were analyzed locoregional recurrences (LR) distant metastases (DM) in head-and-neck cancer....
An addendum to the AAPMˈs TG‐51 protocol for determination of absorbed dose water in megavoltage photon beams is presented. This continues procedure laid out but new k Q data beams, based on Monte Carlo simulations, are presented and recommendations given improve accuracy consistency protocolˈs implementation. The components uncertainty budget determining at reference point introduced magnitude each component discussed. Finally, experimental N D,w coefficients It expected that implementation...
Abstract Traditional radiomics involves the extraction of quantitative texture features from medical images in an attempt to determine correlations with clinical endpoints. We hypothesize that convolutional neural networks (CNNs) could enhance performance traditional radiomics, by detecting image patterns may not be covered a radiomic framework. test this hypothesis training CNN predict treatment outcomes patients head and neck squamous cell carcinoma, based solely on their pre-treatment...
Two recently introduced GafChromic film models, HS and XR-T, have been developed as more sensitive uniform alternatives to MD-55-2 film. The model has specifically designed for measurement of absorbed dose in high-energy photon beams (above 1 MeV), while the XR-T measurements low energy (0.1 MeV) photons. goal this study is compare sensitometric curves estimated dosimetric uncertainties associated with seven different dosimetry systems two new models. densitometers tested are: LKB Pharmacia...
Megavoltage x‐ray beams exhibit the well‐known phenomena of dose buildup within first few millimeters incident phantom surface, or skin. Results surface measurements, however, depend vastly on measurement technique employed. Our goal in this study was to determine a correction procedure order obtain an accurate skin estimate at clinically relevant depth based radiochromic film measurements. To illustrate correction, we have used as reference point . We new dosimetry films (HS, XR‐T, and EBT)...
The purpose of this study was to derive a complete set correction and perturbation factors for output (OF) dose profiles. Modern small field detectors were investigated including plastic scintillator (Exradin W1, SI), liquid ionization chamber (microLion 31018, PTW), an unshielded diode D1V, SI) synthetic diamond (microDiamond 60019, PTW). A Monte Carlo (MC) beam model commissioned use in fields following two commissioning procedures: (1) using intermediate moderately (down 2 × cm2) (2) only...
Purpose: To explain the reasons for significant quality correction factors in megavoltage small photon fields and clarify underlying concepts relevant to dosimetry under such conditions. Methods: The validity of cavity theory requirement charged particle equilibrium (CPE) are addressed from a theoretical point view context nonstandard beams. Perturbation effects described into four main subeffects, explaining their nature pointing out relative importance fields. Results: It is demonstrated...
Background Stratifying high-risk histopathologic features in endometrial carcinoma is important for treatment planning. Radiomics analysis at preoperative MRI holds potential to identify phenotypes. Purpose To evaluate the performance of multiparametric three-dimensional radiomics-based machine learning models differentiating low- from markers—deep myometrial invasion (MI), lymphovascular space (LVSI), and high-grade status—and advanced-stage carcinoma. Materials Methods This dual-center...
Motion of thoracic tumors with respiration presents a challenge for three‐dimensional (3D) conformal radiation therapy treatment. Validation techniques aimed at measuring and minimizing the effects respiratory motion requires realistic deformable phantom use as gold standard. The purpose this study was to develop characteristics reproducible, tissue equivalent, lung phantom. consists Lucite cylinder filled water containing latex balloon stuffed dampened natural sponges. is attached piston...
One of the major drawbacks current radiochromic film dosimetry protocols is postirradiation waiting time. In this article, authors study time evolution absorption spectrum EBT-2 GAFCHROMIC model.Postirradiation scanning times range from 3 min to 5 days and a dose extends 0 6 Gy. The compare results spectra measurements for latest model previous EBT model. also describe method that can establish error constraints on will still provide an acceptable clinical applications if protocol employing...
Purpose: Small‐field dosimetry is challenging, and the main limitations of most dosimeters are insufficient spatial resolution, water nonequivalence, energy dependence. The purpose this study was to compare plastic scintillation detectors (PSDs) several commercial stereotactic by measuring total scatter factors dose profiles on a CyberKnife system. Methods: Two PSDs were developed, having sensitive volumes 0.196 0.785 mm 3 , compared with other detectors. spectral discrimination method...
There are reports that bone marrow cell (BM) transplants repaired irradiated salivary glands (SGs) and re-established saliva secretion. However, the mechanisms of action behind these have not been elucidated.To test if a paracrine mechanism was main effect this reported improvement in organ function, whole BM cells were lysed its soluble intracellular contents (termed as "BM Soup") injected into mice with irradiation-injured SGs. The hypothesis Soup would protect cells, increase tissue...
Purpose: Purpose of this work is to investigate the effects varying active layer composition external beam therapy (EBT) GafChromic TM films on energy dependence film, as well try develop a new prototype with more uniform response at low photon energies (⩽100 keV). Methods: First, overall ( S AD, W Q )) different commercial EBT type film models that represent three generations produced date, i.e., EBT, EBT2, and EBT3, was investigated. Pieces each model were irradiated fixed dose 2 Gy water...
Proton therapy presents an interesting and important challenge to accelerator physics. Practical restrictions such as room size, gantry weight, cost have led a demand for more compact affordable devices. Success would benefit significant number of patients every year. Dielectric wall accelerators could provide this breakthrough, but there is limited work available regarding their feasibility or possible integration into medical devices, no solutions exist longitudinal beam control. In work,...