Brandon Disher, PhD, MCCPM
Title: Medical Physicist
Clinical Duties: SBRT/SRS, 4DCT imaging, respiratory motion management, CT simulator implementation, and quality assurance
Dr. Disher completed his PhD and MSc in Medical Biophysics at Western University, with a concentration in radiation oncology physics, followed by CAMPEP-accredited medical physics residency training at London Health Sciences Centre. His clinical experience spans external beam radiotherapy, stereotactic body radiotherapy, stereotactic radiosurgery, motion management, CT simulation, treatment planning quality assurance, brachytherapy, linac commissioning, and radiation safety.
He has contributed to the commissioning of advanced clinical programs, including Canon CT simulation systems, Calypso-guided lung SBRT, HDR brachytherapy, VMAT lung treatment, and prostate VMAT.
Dr. Disher’s academic and research interests include lung SBRT dosimetry, lateral electron disequilibrium, cone-beam CT and 4DCT imaging, adaptive radiation therapy, dual-energy CT, metal artifact reduction, and motion tracking. He is actively involved in teaching, CAMPEP residency training, mentorship, and professional service through CCPM, COMP, and AAPM.
Bryan Schaly, PhD, MCCPM
Title: Medical Physicist
Clinical Duties: Treatment plan QA, linear accelerator QA and commissioning, high dose rate and low dose rate brachytherapy, physics lead for genitourinary (GU) disease site team, adaptive radiotherapy, Aria/Eclipse resource, re-irradiation team
Dr. Bryan Schaly completed his PhD in Medical Biophysics at the University of Western Ontario in 2004 and completed his Medical Physics Residency at the Odette Cancer Centre in 2006. He then worked at the Grand River Regional Cancer Centre from 2006 to 2012 and returned to the Verspeeten Family Cancer Centre in 2012. His main academic interest currently is in adaptive radiation therapy focusing on bladder cancer treatment on the Varian Ethos machine.
David DeVries
Title: Medical Physicist, Deputy Radiation Safety Officer
Clinical Duties: Brachytherapy, Re-irradiation, Radiation Safety, Linear Accelerator QA and Commissioning, Residency Program Preceptor (External Beam, Commissioning, and Radiation Safety rotations)
Dr. David DeVries completed a MSc in Physics at Queen's University and a PhD in Medical Biophysics at Western University before completing residency at LHS’s Verspeeten Family Cancer Centre.
Beyond his clinical duties, Dr. DeVries supervises residents, graduate and co-op students in research areas such as AI, 3D printing, and 3D optical scanning. Dr. DeVries is also the chair of the CADRA Data Sharing committee to move radiotherapy in Canada towards data sharing for clinical and research purposes.
Donna Murrell, PhD MSc MCCPM
Titles: Medical Physicist, Assistant Professor, Departments of Oncology and Medical Biophysics, Western University
Clinical Duties: Reirradiation lead, Thoracic Disease-Site lead, HDR Brachytherapy, SBRT/SABR
Dr. Murrell earned her BSc, MSc, and PhD degrees from Western University and completed her residency at LHSC before joining the Radiation Oncology program in 2018. She provides broad clinical service with high standards of care and a thoughtful, pragmatic approach to complex clinical challenges.
Her work focuses on translating new knowledge and technical innovation into safer, more effective patient-centered care. She leads international and national efforts to advance the field of reirradiation, contributes to clinical trials, and participates in the development of clinical guidelines that inform practice. Her professional service includes membership on the national Quality Assurance and Radiation Safety Advisory Committee, along with ongoing contributions to education and mentorship.
Douglas Hoover, PhD, MCCPM
Title: Medical Physicist
Clinical Duties: Brachytherapy Lead, Adaptive Radiotherapy, Brain SRS, Head & Neck Physics Lead
Dr. Hoover is a clinical Medical Physicist at the Verspeeten Family Cancer Centre, an Assistant Professor in the Department of Oncology at Western University, and an Adjunct Professor at McGill University. He is the physics lead for their active brachytherapy service, which treats approximately 300 patients annually. His clinical and research interests focus on image-guided brachytherapy, including the use of micro-ultrasound for prostate cancer treatment and the development of intra-operative 3D ultrasound for gynecological brachytherapy, as well as the development and integration of novel software and machine learning tools into the brachytherapy workflow.
Dr. Hoover has led several technical and quality improvement initiatives within radiation oncology, including the development of clinical documentation and safety reporting systems. He is actively involved in clinical trials and multidisciplinary research aimed at improving the safety, quality, and clinical outcomes within brachytherapy. Cancer sites of interest include Head and Neck, GU, and GYN.
Eric Lessard, PhD, MCCPM
Titles: Medical Physicist, Assistant Professor, Departments of Oncology and Medical Biophysics, Western University
Clinical Duties: Stereotactic Radiosurgery, Magnetic Resonance Imaging, Clinical Education and Supervision (Treatment Planning), and Reirradiation
Eric Lessard joined the Verspeeten Family Cancer Centre in 2024. Prior to this, he completed his medical physics residency at the Juravinski Cancer Centre, his graduate work at Western University, and his undergraduate work at the University of Windsor. His academic and research interests include the translation of MR techniques towards treatment planning as well as the optimization of stereotactic (SRS/SBRT) planning for complex multi-lesion treatments and in cases of retreatment.
Jennifer Dietrich B.A.Sc., M.Sc., P.Eng
Title: Physics Associate
Clinical Duties: Routine Quality Assurance, Patient Specific QA, supervision of QA students
Jennifer is a recent addition to the Verspeeten Family Cancer Centre having spent the previous 22 years in industry developing QA devices for use in radiotherapy. Research interests include quality systems in radiation therapy and motion management in RT.
Jason Lee, PhD
Title: Medical Physicist
Clinical Duties: Brachytherapy, Total Body Irradiation
Dr. Jason Lee completed his medical physics residency at the Juravinski Cancer Centre in Hamilton and holds a PhD in Medical Physics. His clinical interests include brachytherapy, stereotactic and complex treatment planning, treatment planning, quality assurance, and adaptive radiation therapy.
Dr. Lee is particularly interested in leveraging automation and software development to improve clinical efficiency, quality, and safety within radiation oncology workflows through ESAPI scripting and other informatics-based solutions. His research interests span targeted radionuclide therapy, radiotherapy optimization, and the integration of technology to enhance patient care.
Jason Vickress, PhD, MCCPM
Title: Medical Physicist
Clinical Duties: Tomotherapy, Adaptive Radiotherapy lead, reirradiation
Dr. Jason Vickress is a Medical Physicist who completed his graduate studies at Western University in 2018, specializing in deformable image registration, followed by a medical physics residency at Credit Valley Hospital in 2020. He has been practicing since 2020 with a clinical practice encompassing external beam radiotherapy, TomoTherapy, adaptive radiotherapy, and reirradiation. He has played a leading role in the development and implementation of adaptive radiotherapy and reirradiation programs, as well as an automated breast tangent treatment planning program. His research interests focus on adaptive radiotherapy (both online and offline), treatment planning automation, and brachytherapy, with an emphasis on improving the precision, efficiency, and quality of radiation therapy delivery.
John C. Patrick, PhD, DABR
Title: Medical Physicist
Clinical Duties: LDR brachytherapy for prostate, motion management, surface-guided radiation therapy, SRS, TBI, AI-based auto-contouring systems, Automation
Dr. Patrick completed a CAMPEP-accredited Medical Physics Residency at London Health Sciences Centre following a PhD and MSc in Medical Biophysics from Western University. His graduate research focused on PET/MRI imaging, attenuation correction, and motion characterization for radiotherapy applications. Prior to his current role, he served as an Associate Medical Physicist at the Lifespan Cancer Institute/Rhode Island Hospital and held academic appointments at Brown University, the University of Rhode Island, and Tufts University.
Dr. Patrick’s research and academic interests include medical imaging, brachytherapy, motion management, automation, and artificial intelligence in radiation oncology. He has authored peer-reviewed publications, presented extensively at national and international conferences, and contributes to the education and mentorship of medical physics trainees and students.
Jonatan Snir, MSC, PhD, MCCPM
June Cheng Baron, PhD, MCCPM (Associate Residency Director)
Title: Medical Physicist, Associate Residency Director
Contact Information: June.ChengBaron@lhsc.on.ca
Clinical Duties: Brachytherapy, Adaptive Radiotherapy, Reirradiation, Motion Management, Cardiac Radioablation
Dr. June Cheng Baron has been a physicist at the Verspeeten Family Cancer Centre since the fall of 2024. She obtained her PhD in Cardiac Magnetic Resonance Imaging at the University of Alberta and completed the University of Toronto Department of Radiation Oncology Physics Residency Program with the Durham Regional Cancer Centre in Oshawa as her home site. She is currently the Associate Program Director for the Verspeeten Physics Residency Program.
Kathleen Surry, PhD, MCCPM
Titles: Academic Medical Physicist, Assistant Professor, Departments of Oncology and Medical Biophysics, Western University, CAMPEP Program Director, Department of Medical Biophysics, Western University
Clinical Duties: Academic Physicist (Western University), HDR Brachytherapy, EXB plan QA, Clinical Education and Supervision (Brachytherapy), Medical Physics Steering Committee
Kathleen Surry has a long history of service in the HDR brachytherapy group at the Verspeeten Family Cancer Centre, with a particular interest in advancing treatments for GYN cancer. She also provides general clinical support to the EXB clinical program.
Dr. Surry is the Program Director of the CAMPEP Graduate Program in Medical Biophysics at Western University. Dr. Surry teaches courses in practical application of physics in radiation therapy, professional practice in medical physics, and introduction to technology in cancer therapy at Western.
Research interests include: the application of 3D ultrasound to intra-operative guidance for GYN BT; equity and diversity in medical physics; and professionalism skill development in the clinical physics education setting.
Dr. Surry is active in the Canadian Organization of Medical Physicists (COMP), serving as Chair of the CWC-IDEA group from 2019-22, the Vice President from 2022-24, President from 2024-26, and the Past President from 2026-28.
Matthew Mouawad, MSc, PhD, MCCPM (Residency Director)
Title: Medical Physicist, Residency Director, Associate Professor in departments of Oncology and Medical Biophysics, Western University
Contact Information: Matthew.Mouawad@lhsc.on.ca
Clinical Duties: Automation, Adaptive Radiotherapy, Reirradiation, Treatment Planning, TBI
Dr. Matthew Mouawad is a medical physicist whose clinical work focuses on automation, treatment planning, and adaptive radiotherapy. He completed his graduate training in Medical Physics at Western University and his residency at the Verspeeten Family Cancer Centre, with clinical experience in SBRT motion assessment and automation.
A key focus currently is the Residency program and further enhancing our competency-based evaluation. He is involved in departmental teaching and supports quality improvement initiatives related to radiotherapy planning and delivery.
View Matthew's ORCID profile.
Matthew Mulligan
Title: Physics Associate
Clinical Duties: Linac QA, Patient Specific QA, LDR Brachytherapy, QA Committee, Commissioning
Matt Mulligan completed his undergraduate degree at Waterloo University in Honours Applied Physics. He started working at London Health Sciences Centre as a research associate funded through Western University in 1999. In 2002, he started work as a Physics Associate and has helped develop and update the QA program. His clinical interests revolve around all QA processes and include education and training of term students and Residents. His research interests include Monte Carlo, and LDR Brachytherapy. On a provincial level, Matt is currently a member of the CCO - QA data management group.
Samuel Blake, PhD, MCCPM
Title: Medical Physicist
Clinical Duties: SRS, SBRT/SABR, 4DCT imaging, respiratory motion management, treatment plan QA, linear accelerator QA, LDR brachytherapy
Sam Blake completed his PhD in Medical Physics at the University of Sydney (Australia) in 2015, followed by three postdoctoral appointments at the University of Sydney and Image-X Institute (2015-2022). He completed a CAMPEP MSc in Clinical Medical Biophysics at Western University in 2023 and thereafter trained as a resident at the Verspeeten Family Cancer Centre (2023-2025), where he now works as a medical physicist.
Dr. Blake's academic and research interests include the use of advanced imaging techniques in radiotherapy simulation, treatment planning and delivery. He is also actively involved in clinical education and training of residents, supervision of undergraduate co-op student research projects, and community outreach programs.
Tomi Nano, PhD, DABR
Titles: Medical Physicist, Assistant Professor (Departments of Oncology and Medical Biophysics, Western University)
Clinical Duties: SRS, SBRT/SABR, HDR, LDR, 4DCT imaging, respiratory motion management, treatment planning
Dr. Nano completed his PhD and MSc in Medical Biophysics at Western University and Robarts Research Institute, followed by CAMPEP-accredited medical physics residency training at the University of California, San Francisco (UCSF). His clinical experience spans external beam radiotherapy, stereotactic body radiotherapy, stereotactic radiosurgery, brachytherapy (HDR/LDR), motion management, CT simulation and treatment planning quality assurance.
Dr. Nano’s academic and research interests include SRS/SBRT dosimetry, 4DCT imaging, adaptive radiation therapy, surface-guided radiotherapy and artificial-intelligence. He is actively involved in teaching, CAMPEP residency training, mentorship, and professional service through COMP, and AAPM.
Yudy Ascencion Ybarra, MSc
Title: Physics Associate
Clinical Duties: Routine Quality Assurance, Patient Specific QA, LDR brachytherapy treatment planning, supervision of QA students
Yudy’s recent work has focused on improving the CT quality assurance procedure and collecting and analyzing the data to implement the Jaw tracking QA program. Yudy has a longstanding interest in quality assurance, dosimetry, commissioning, image-guided radiation therapy, and emerging radiotherapy technologies.
