Medical Physics Graduate Program Faculty

Stephen Steciw, PhD, MCCPM

Assistant Professor, Division of Medical Physics, Department of Oncology, University of Alberta

Medical Physicist, Dept. of Medical Physics, CCI

BSc (Honors Physics: Alberta - 1995)
PhD (Medical Sciences - Radiology & Diagnostic Imaging: Alberta - 2001)

Member: Canadian College of Physicists in Medicine

Research Interests

MR-Linac: Magnetic Interference

Real-time image-guided adaptive radiotherapy (RTIGAR) is being explored at the Cross Cancer Institute by coupling a 0.2 T biplanar permanent-magnet MRI to a linear accelerator. My research involves using finite element analysis and other specialized software to study the effects of the magnetic interference from the MRI system on the production of an x-ray beam intended for use in radiotherapy. I am also investigating passive and active shielding methods to eliminate the effects of this magnetic interference.

EPID Modeling and Dosimetry

My research interests also include dosimetric modeling of EPIDs for exit-beam and IMRT verification. Monte Carlo modeling, with the addition of lag and ghosting correction algorithms are being investigated to improve the dosimetric response derived from the EPID.

Selected Publications

D. Baillie, J. St-Aubin, B.G. Fallone, S. Steciw,
"Feasibility of producing a short, high energy s-band linear accelerator using a klystron power source"
Med. Phys. 40(4), 041713/5 (2013)

B Warkentin, S Rathee, S. Steciw,
"2D Lag and signal non-linearity correction in an aS500 EPID and their impact on pretreatment dosimetric verification"
Med. Phys. 39(11), 6597-6608 (2012).

D. Robinson, D. Liu, S. Steciw, C. Field, H. Daly, S. Kumar, G. Fallone, M. Parliament, J. Amanie,
"Prospective Study to Evaluate the Accuracy and Inter-User Variability of the Clarity 3-Dimensional Ultrasound System for Verification during External Beam Radiation Therapy for Clinically Localized Prostate Cancer"
JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS. 13(4), 100-112 (2012).

D.M. Santos, J. St-Aubin, B.G. Fallone, S. Steciw,
"Magnetic shielding investigation for a 6 MV in-line linac within the parallel configuration of a linac-MR system"
Med. Phys. 39, 788-797 (2012).

J. St-Aubin, S. Steciw, B.G. Fallone,
"Waveguide detuning caused by transverse magnetic fields on a simulated in-line 6 MV linac"
Med. Phys. 37, 4751-4754 (2010).

J. St-Aubin, S. Steciw, B.G. Fallone,
"Magnetic decoupling of the linac in a low field biplanar linac-MR system"
Med. Phys. 37, 4755-4761 (2010).

J. St-Aubin, D.M. Santos, S. Steciw, B.G. Fallone,
"Effect of longitudinal magnetic fields on a simulated in-line 6 MV linac"
Med. Phys. 37, 4916-4923 (2010).

J. St-Aubin, S. Steciw, B.G. Fallone,
"Effect of transverse magnetic fields on a simulated in-line 6 MV linac"
PHYSICS IN MEDICINE AND BIOLOGY Volume: 55 Issue: 16 Pages: 4861-4869 Published: AUG 21 2010.

J. St-Aubin, S. Steciw, B.G. Fallone,
"An integrated 6 MV linear accelerator model from electron gun to dose in a water tank,"
Medical Physics, 37(5), pp. 2279-2288 (2010).

J. St-Aubin, S. Steciw, B.G. Fallone,
"The design of a simulated in-line side-coupled 6 MV linear accelerator waveguide,"
Medical Physics, 37(2), pp. 466-476 (2010).
[selected for Virtual Journal of Biological Physics Research, Jan. 15 , 2010]

B.G. Fallone, B. Murray, S. Rathee, T. Stanescu, S. Steciw, S. Vidakovic, E. Blosser and D. Tymofichuk,
"First MR images obtained during megavoltage photon irradiation from a prototype linac-MR system."
Med. Phys. 36, 2084-2088(2009).

S. Steciw, B. Warkentin, S. Rathee, et al.,
"Three-dimensional IMRT verification with a flat-panel EPID."
MEDICAL PHYSICS 32 (2): 600-612 FEB 2005.

T.T. Monajemi, S. Steciw, B.G. Fallone, et al.,
"Modeling scintillator-photodiodes as detectors for megavoltage CT."
MEDICAL PHYSICS 31 (5): 1225-1234 MAY 2004.

B. Warkentin, S. Steciw, S. Rathee, et al.,
"Dosimetric IMRT verification with a flat-panel EPID."
MEDICAL PHYSICS 30 (12): 3143-3155 DEC 2003.

S Steciw, T. Stanescu, S. Rathee, et al.,
"Sensitivity reduction in biased amorphous selenium photoconductors."
JOURNAL OF PHYSICS D-APPLIED PHYSICS 35 (21): 2716-2722 NOV 7 2002.

Selected Abstract Publications

J St. Aubin, S Steciw, B Fallone,
"Simulation of an In-Line 6MV Linear Accelerator from Electron Gun to Target."
MEDICAL PHYSICS 36 (6): 2802-2802 JUL 2009.

S Steciw, B Warkentin, S Rathee, B Fallone,
"A Comprehensive MLC Dose Model: Use in Dynamic IMRT Verification Using an EPID"
MEDICAL PHYSICS 36 (6): 2566-2566 JUN 2009.

S Steciw, B Warkentin, S Rathee, et al.,
"2-D lag and response nonlinearity corrections for dynamic IMRT verification using an EPID"
MEDICAL PHYSICS 35 (7): 3400-3400 JUL 2008.

J St. Aubin, S Steciw, M Carlone, et al.,
"The effect of magnetic interference on a coupled MR-linac system: Optimization of 3D FEM model"
MEDICAL PHYSICS 35 (7): 3411-3411 JUL 2008.

S Steciw, T Stanescu, M Carlone, et al.,
"Magnetic shielding of a coupled MRI-Linac system"
MEDICAL PHYSICS 34 (6): 2623-2623 JUN 2007.

T Stanescu, S Steciw, S Rathee, et al.,
"Sensitivity reduction in a-Se radiation detectors"
MEDICAL PHYSICS 31 (6): 1810-1811 JUN 2004.

S Steciw, B Warkentin, S Rathee, et al.,
"A Monte Carlo based method for accurate measurement of fluences using the aS500 EPID"
MEDICAL PHYSICS 30 (7): 1944-1944 JUL 2003.

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