Associate 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

S. Steciw,
"A convolution-superposition fluence model for the Siemens HD120 multi leaf collimator with application to a 3D VMAT dose engine",
Biomed. Phys. Eng. Express 9 (2023) 065004

S. Rathee, B.G. Fallone, S. Steciw,
"Technical Note: EPID's response to 6 MV photons in a strong, parallel magnetic field",
MEDICAL PHYSICS. 46(1),340-344 (2019)

A. Ghila, S. Steciw, B.G. Fallone, S. Rathee,
"Experimental verification of EGSnrc Monte Carlo calculated depth doses within a realistic parallel magnetic field in a polystyrene phantom",
Medical Physics, 44(9), pp. 4804-4815 (2017)

D. Baillie, B.G. Fallone, S. Steciw,
"Design and simulation of a short, variable-energy 4 to 10 MV linear accelerator waveguide",
Medical Physics, 44(6), pp. 2124-2131 (2017)

D. Baillie, J. St.Aubin, B.G. Fallone, S. Steciw,
"FEM design and simulation of a short, high-energy, S-band linac with Monte Carlo dose simulations",
Medical Physics, 42(4), pp. 2044-3052 (2015),
PubMed Link

S Steciw, S Rathee, B Warkentin,
"Modulation factors calculated with an EPID-derived MLC fluence model to streamline IMRT/VMAT second checks"
Journal of Applied Clinical Medical Physics. 14(6), 62-81 (2013).

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.

Book Chapters

G Fallone, B Murray, B Burke, A Keyvanloo, S Rathee, J St. Aubin, S Steciw, K Wachowicz, B Warkentin, Y Yun,
Chapter 6: Design and Development of Linac-MR Hybrids
in A B Wolbarst (Ed.) Advances in Medical Physics, Volume 6. (pp. 113:142).Madison WI: Medical Physics Publishing. (2016)

Selected Abstract Publications

D. Baillie, J. St-Aubin, B.G. Fallone, S. Steciw,
"New Compact 10 MV S-Band Linear Accelerator: 3D Finite-Element Design and Monte Carlo Dose Simulations",
MEDICAL PHYSICS. 41(6), 562 (2014)

D. Baillie, J. St-Aubin, B.G. Fallone, S. Steciw,
"Design and simulation of a short, 10 MV, S-band linear accelerator",
MEDICAL PHYSICS. 40(6), 446 (2013)

D. Baillie, J. St-Aubin, B.G. Fallone, S. Steciw,
"Redesign of a 6 MV linear accelerator waveguide to produce energies up to 10 MV",
MEDICAL PHYSICS. 39(6), 3859 (2012)

D. M. Santos, St. Aubin J, Fallone B, Steciw S,
"Investigation of magnetic shielding for a 6MV in-line linac for a parallel linac-MR configuration",
MEDICAL PHYSICS. 38(6), 3830 (2011).

St. Aubin J, Steciw S, Fallone B,
"Magnetically Shielding the Linac in a Bi-Planar Linac-MR System",
MEDICAL PHYSICS. 37(7), 3886 (2010).

St. Aubin J, Steciw S, Fallone B,
"The Effect of Transverse Magnetic Fields on a Simulated In-Line 6 MV Linac",
MEDICAL PHYSICS. 37(6), 3468 (2010.)

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.