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Robert Stewart, Ph.D.

Associate Professor


Dr. Stewart is an internationally recognized authority on the applications of computer modeling in radiation biophysics. In 2005, Dr. Stewart and colleagues developed a novel Monte Carlo model to simulate the induction and base excision repair (BER) of clustered DNA lesions. The 2011 version of the Monte Carlo Damage Simulation (MCDS v. 3.1) developed by Stewart and colleagues is a first of kind, and at present, the only Monte Carlo model capable of providing nucleotide-level maps of the clustered DNA lesions formed in cells irradiated under reduced oxygen conditions. The Monte Carlo models for the induction and repair of DNA damage are part of his more than decade-long effort to develop a multi-scale system of models to capture essential aspects of the early physical, chemical and biological processes underlying cell death kinetics.


Area(s) of Research Focus:

  • Biologically guided radiation therapy (BGRT), outcome assessment and treatment individualization using biological metrics, such as the equivalent uniform dose (EUD) and biologically equivalent dose (BED) concepts
  • Positron Emission Tomography (PET) and Boron Neutron Capture Therapy (BNCT) using the UW Clinical Neutron Therapy System (CNTS)
  • Basic and applied research on molecular and cellular mechanisms of radiation injury, especially the induction and biological processing of DNA damage. Project leader for the development of the Monte Carlo Damage Simulation (MCDS) and the Monte Carlo Excision Repair (MCER) models
  • Effects of particle linear energy transfer (LET) and oxygen on DNA damage, reproductive cell death, and clinical endpoints (tolerance doses for healthy and equivalent tumor prescriptions)
  • Radiation physics, dosimetry and microdosimetry. Over 18 years of experience with Monte Carlo radiation transport codes, including PENELOPE, MCNP, EGS4, and EGSnrc

Education and Training

College: Kansas State University, Manhattan, KS

Graduate School: Kansas State University, Manhattan, KS

Published Works

I. Seth*, J.L. Schwartz, R.D. Stewart, R. Emery, M.C. Joiner, J. D. Tucker, Neutron exposures in human cells: bystander effect and relative biological effectiveness. Accepted by PLoS One on May 9th, 2014 (initial submission date March 3, 2014). Manuscript # PONE-D-14-09785R1.

JL Schwartz, D Murray, RD Stewart, MH Phillips, Modeling Clinical Radiation Responses in the IMRT Era. Journal of Physics: Conference Series. XVII International Conference on the Use of Computers in Radiation Therapy (ICCR2013) 489 (2014) 012059. doi:10.1088/1742-6596/489/1/012059

D Corwin, C Holdsworth, R Rockne, AD Trister, MM Mrugala, JK Rockhill, RD Stewart, M Phillips, KR Swanson, Toward patient-specific, biologically optimized radiation therapy plans for the treatment of glioblastoma. PLoS One. 2013 Nov 12; 8(11): e79115. doi: 10.1371/journal.pone.0079115.

C Kirkby, E Ghasroddashti, Y Poirier, M Tambasco, RD Stewart, Monte Carlo Simulations of Relative DNA Damage From KV CBCT Radiation. Phys. Med. Biol. 58, 5693-5704 (2013). doi: 10.1088/0031-9155/58/16/5693.

AG Georgakilas, P O’Neill, RD Stewart, Induction and Repair of Clustered DNA Lesions: What Do We Know So Far? Radiat. Res. 180, 100-109 (2013). doi: 10.1667/RR3041.1.

Board Certification

American Board of Radiology, Therapeutic Medical Physics part 1 2011