Welcome to the Division of Radiation Oncology.

It is my pleasure to welcome you to the Division of Radiation Oncology website. This has been developed to provide information for health professionals and trainees on the Division’s clinical, research and educational activities. Information for patients can be found on the Radiation Medicine Program page of The Ottawa Hospital (TOH).

The Division of Radiation Oncology is a member of the Department of Radiology, Radiation Oncology and Medical Physics at the University of Ottawa Faculty of Medicine. The Division provides all radiation oncology services within the Champlain Local Health Integration Network with a population of over 1.4 million.

There are currently 22 radiation oncologists supported by allied health professionals in tumour site specific teams. When combined with the TOH Medical Physics and Radiation Therapy departments, the Radiation Medicine Program is one of the largest in North America with significant expertise in complex radiotherapy techniques including Stereotactic radiotherapy and brachytherapy. The Division has a leading role in conducting local, national and international clinical trials in association with The Ottawa Hospital Research Institute. The Division also fulfills its academic role through undergraduate, postgraduate and continuing medical education activities.

Marc Gaudet MD MSc MHA FRCPC
Head, Division of Radiation Oncology
Assistant Professor of Radiation Oncology,
University of Ottawa

Our Team

Radiation oncologists are medical specialists whose expertise is in cancer care and prescribing radiation as part of the cure or symptom relief of patients. They work closely with their medical and surgical oncology colleagues to develop treatment plans for each individual patient. In rare situations, benign tumours are also treated by radiation oncologists.

Once prescribed, radiation is planned and administered by radiation therapists who ensure that the prescribed dose is delivered safely and appropriately. Medical physicist act behind the scenes to ensure accuracy through precise monitoring of equipment and processes.

Team Leaders include:

Marc Gaudet MD FRCPC
Chief, Division of Radiation Oncology

Melissa Diffey, MRT(T) (R)
Manager Radiation Therapy
Tel: 737-7700 ext 70192
Email: [email protected]

Miller MacPherson, PhD FCCPM
Head of Physics
Tel: 613-737-7700 x 70011
Email: [email protected]

Dr. Marc Gaudet, Melissa Diffey and Miller MacPherson
Dr. Marc Gaudet, Melissa Diffey and Miller MacPherson



The Ottawa Hospital Cancer Program, affiliated with the University of Ottawa, is one of the largest cancer programs in Canada. We have an active fellowship program with multiple candidates in place at present. Our radiation treatment facilities include: three wide bore CT simulators with 4D capability, high dose rate and low dose rate Brachytherapy, nine VMAT capable Elekta Linear Accelerators with cone-beam CT capability. There are two Tomotherapy units and one CyberKnife unit. The main planning system used is Monaco/Raystations and Accuracy Precision software for Tomotherapy and Cyberknife.

The Ottawa Hospital Cancer Centre is the sole provider of radiation oncology services in the Champlain LHIN (population 1.3 million) with over 5000 new patient consults annually. Radiation Oncology offers fellowships in Cyberknife and SBRT. All qualified candidates may apply; however, preference will be given to Canadian applicants who have successfully completed Royal College certification in Radiation Oncology.

Application procedure for Canadian Trained Candidates:

1. Curriculum Vitae,

2. Three recent letters of reference,

3. Letter outlining interest in fellowship, learning goals and potential projects

Application Procedure for foreign applications:

Program accepts applications from July – September of the academic year. Foreign trained physicians interested in a fellowship at The Ottawa Hospital are required to apply on the University of Ottawa website.

awards on display at the saturday night gala


Click the link below for a list of our Alumni
Alumni List

Service and Equipment

Our Services

The Radiation Medicine Team is dedicated to providing compassionate care to radiation patients with cancer. We use a wide range of technically advanced radiotherapy techniques that aggressively target tumours while reducing side effects. These techniques represent some of the most advanced technology in the field and are matched by few centres elsewhere

  • Intensity-Modulated Radiation Therapy/VMAT
  • Image-Guided Radiation Therapy (IGRT)
  • Total Body Radiation 
  • Radiosurgery and Radiation Therapy including CyberKnife®
  • Interstitial and Intracavitary Brachytherapy
  • Palliative Radiation Oncology Program
  • Radiation for children with cancer in partnership with CHEO
  • Inpatient admission to hospital when required

Contact Us


501 Smyth Road, Box 232
Ottawa, Ontario
Canada K1H 8L6
Tel: 613-737-8571
Fax: 613-737-8830

Taylor Widenmaier
Interim Administrative Coordinator
E-mail: [email protected]