Clinical Professor Emeritus, Division of Medical Physics, Department of Oncology, University of Alberta

Senior Medical Physicist, Dept. of Medical Physics, CCI
Retired 2016.

MSc Medical Physics: McGill-1981
BSc Biophysics: Western Ontario-1977

Fellow and Board Member: Canadian College of Physicists in Medicine
Fellow: Canadian College of Physicists in Medicine
Member: Canadian College of Physicists in Medicine

Clinical Research Interests

Breast RT Treatment Techniques

There has been a resurgence of interest in the irradiation of internal mammary lymph nodes for the treatment of breast cancer. Irradiation of the internal mammary nodes in conjunction with chemotherapy treatment has been shown to increase survival for pre-menopausal breast cancer patients. The treatment of the breast, supraclavicular, axillary and intra-mammary nodes is a highly complex and challenging treatment planning problem. Traditional techniques utilizing 4, 5 & 6 radiation portals may unnecessarily irradiate critical structures such as lung and heart. Our center has treated many patients using the wide tangent mono-isocentric breast technique, the focus of a National Cancer Institute of Canada (NCIC) protocol, MA 20.

Intensity Modulated Radiotherapy for Breast

Intensity modulated radiotherapy (IMRT) uses computer optimization to determine the fluence profile of each beam such that the combination of all beams will provide a dose distribution that meets predefined sets of conditions. The breast is an ideal site for the use of IMRT as it may significantly lessen the irradiation of heart and lung and deposit the radiation dose more specifically to the target volume.

Orthovoltage Dosimetry

Acceptance testing and complete commissioning of any treatment machine is a major responsibility for medical physicists. An extended analysis of beam parameters for the orthovoltage machine Pantax 300DXT revealed manufacturing defects for this machine. Given that many units are clinically implemented using published data, a systematic commissioning procedure is recommended for all treatment machines of this type using appropriate dosimeters. Collation of precise treatment data is critical for the treatment of a variety of sites in ordinary clinical practice.

Selected Recent Publications

K Breitman, S Rathee, C Newcomb, B Murray, D Robinson, C Field, H Warkentin, S Connors, M MacKenzie, P Dunscombe and B G Fallone,
"Experimental Validation of the Eclipse AAA Algorithm."
J. App. Clin. Med. Phys, 8(2), pp.76-92, Spring (2007).

D Severin, S Connors, H Thompson, S Rathee, P Stavrev and J Hanson,
"Breast radiotherapy with inclusion of the internal mammary nodes: A comparison of techniques with 3 dimensional planning."
IJROBP 55(3), pp. 633-644, 2003.

R Scrimger, S Connors, S Halls and A Starreveld,
"CT-Targeted irradiation of the Breast and Internal Mammary Lymph Nodes using a 5-Field Technique."
IJROBP 48(4), pp. 983, 2000.