Erno Sajo

Erno Sajo, Physics, Medical Physics

Erno Sajo, Physics, Medical Physics

Professor, Director
207 Pinanski Hall


Medical Physics & Radiological Science

Research Interest

I study the fundamental interactions between radiation and biological matter with particular emphasis on cancer therapy. The description of the involved phenomena requires the understanding and solution of Boltzmann's transport equation, one of the most complex and most difficult theories of Nature. The same equation, applied at the hydrodynamic limit, describes the transport and interactions of colloids, including aerosols. Thus, by way of mathematical physics, two seemingly different physical phenomena are brought together and have significant commonality. Hence, my field of interest is radiation biology, radiation transport, and aerosol transport or colloid interface science. The latter is part of nano science, and it has found applications, or the promise thereof, in cancer treatment. In radiation science, my current research centers on understanding the types of chromosomal and DNA damages, including the risk of heritable intragenic mutations, caused by high vs low linear energy transfer radiation. This includes dose computations at the micro- and nano- scales in charged particle disequilibrium. Application of this work ranges from Auger therapy to secondary cancer induction, and extends to investigating the possibility of targeting biomolecules other than the DNA in cancer therapy. Other related areas where I have been active is prostate brachytherapy, where with ML Williams we developed a new method to directly assay the prostate dose following permanent interstitial implant, without having to explicitly find the locations of implanted seeds - an error-prone procedure, which is currently widely used. A US Patent has been awarded. In colloids, I am interested in nanoparticle cancer treatment and in aerosol transport - two related areas of colloid interface science whose physical and mathematical description bear similarities. In confined spaces particles undergo dynamic sequential many-body interactions with or without chemical reactions while transported in the medium. Over the last few years, my research group developed a computational aerosol transport system, which tracks the macroscopic aerosol phase space. It computes the time-resolved size-specific aerosol distribution in space following the release of aerosol species in arbitrary geometry and arbitrary initial size distribution.

Educational Background

Ph.D., 1990 - University of Lowell


Current and selected publications:

JP Dugas, ME Varnes, CE Welch, E Sajo, K Ham, KR Hogstrom, "Dependence
of Cell Survival on IUdR Concentration in 35 keV Photon-activated
Auger Electron Radiotherapy." Int. J. Radiation Oncology Biology
Physics, 2010.

Wallace WH, Sajo E, Nielsen BJ, Heimbuch BK, Owens JR, Wander JD.
"Deposition of Bacillus Spores on Zero-Volume Airlock Materials."
Aerosol Sci and Tech., 2010.

E. Sajo. "Evaluation of the exact coagulation kernel under
simultaneous Brownian motion and gravitational settling." Aerosol Sci
and Tech. 42:134-139, 2008.

Shiomitsu K, Sajo E, Xia X, Hunley DW, Mauldin G, Shulin L, Mauldin
GN. "Radiosensitivity of canine osteosarcoma cells transfected with
wild type p53 in vitro." J. Vet. Comparative Oncology. v.6, n.3 pp.
193-200, 2008.

Dugas PJ, Oves SD, Sajo E, Matthews KL, Ham K, Hogstrom KR.
"Monochromatic Beam Characterization for Auger Electron Dosimetry and
Radiotherapy at CAMD." European J Radiology. v.68, Issue 3, pp.
S137-141, 2008.

Oves SD, Hogstrom KR, Ham K, Sajo E, Dugas JP. "Dosimetry
intercomparison using a 35 keV X-ray synchrotron beam." In press, 
European J Radiology. v.68, Issue 3, pp. S121-125, 2008.

E. Sajo, M.L. Williams, "Embedded Radiation Emitter for the
Localization and Dosimetry of Brachytherapy Seed Implants".  US Patent
6,761,679, July 13, 2004.

E. Sajo and Williams ML. "TransMED: Deterministic Photon Transport for
External Beam Therapy." in "Software and Data Tools in Medical and
Health Physics Radiation Transport Applications" Edited by B. Kirk,
ORNL. 2005. Published by Oak Ridge National Laboratory as a DOE
technical report, ORNL/TM-2006/7. August, 2006.

M.L. Williams, D. Ilas, E. Sajo, "Deterministic Photon Transport
Calculations in General Geometry for External Beam Radiation Therapy
Calculations" Medical Physics, 30 (12), pp. 3183-3195, 2003.