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James Gräfe, PhD, MCCPM

Assistant Professor

416-979-5000 x3405
james.grafe@ryerson.ca

Specialization

Medical Physics, radiation therapy, in vivo trace and toxic metal analysis, in vivo neutron activation analysis, in vivo X ray fluorescence, gadolinium toxicity, innovative nuclear medicine, proton prompt gamma ray, Proton Neutron Gamma-X Detection (PNGXD).

Research

My research revolves around developing innovative techniques in applied nuclear medicine or radiation therapy through experiment and simulation.

A few projects that I am currently working on are:

Proton Neutron Gamma-X Detection (PNGXD): I am currently actively recruiting students to be involved in my latest research project investigating the potential to image a gadolinium-based contrast agent during proton therapy by neutron activation. Interested potential graduate students are welcome to contact me. More details can be found here: http://www.sciencedirect.com/science/article/pii/S0168583X17306080

Gold nano-particle radio-sensitization: I am currently recruiting a student to investigate gold nano-particle radio-sensitization through Monte Carlo simulation. There have been many simulations investigating the enhancing effect of gold nano-particles, however many simulations and experiments disagree in the Mega-voltage region of therapeutic energies. Combining experiment and simulation, this project aims to explain the discrepancies that have been observed in the literature.

In vivo detection of rare earth elements: The use of REE is increasing in popularity in both industry and medicine. However, these metals in their free form are toxic and can cause fibrosis, calcium deposition, inflammation, and necrosis to a variety of different organs and tissues. Gadolinium (Gd), Samarium (Sm), and Lanthanum (La) are three REE of particular interest due to industrial practices, mining, medical applications, and water contamination from anthropogenic activity. Gd-based contrast agents (GBCAs) are the most routinely used contrast agents in magnetic resonance imaging (MRI). La-carbonate is used as a phosphate binder in chronic kidney disease. However, with these applications there is the potential for residual amounts of rare earth metals to be deposited in the human body with potential toxic consequences. Increasing evidence is appearing in the literature about Gd deposition in the bone and brain for patients administered a GBCA. Furthermore, Health Canada recommends longer follow-up studies on bone health and bone quality due to residual La from a common La-based drug approved for use in Canada.
This research aims to design non-invasive systems that can measure rare earth metal concentration in the human body using the atomic and nuclear spectroscopic signatures of the REE.

Research Opportunities / Open Positions

The following positions are open in my lab. Interested applicants are welcome to contact me for more information. More details on how to apply can be found at the links below.

  1. I am currently recruiting 2 MSc level students to conduct research beginning in the Fall of 2018 at Ryerson University.
  2. I am also recruiting a PhD student for Fall of 2018 to conduct joint research at the Washington University School of Medicine in St. Louis and Ryerson University.

Publications

[1] J. Nguyen*, Z. Keldani*, E. Da Silva, A. Pejovic-Milic, J. Gräfe. The feasibility of in vivo detection of lanthanum using a 241Am K X-ray Fluorescence system. Accepted July 28 2017. Physiological Measurement. doi.org/10.1088/1361-6579/aa82d8
[2] Gräfe,JL. Proton Neutron Gamma-X Detection (PNGXD): An introduction to contrast agent detection during proton therapy via prompt gamma neutron activation. Nuclear Instruments and Methods in Physics Research Section B 2017 407 20-23. https://authors.elsevier.com/a/1V6xN,3rKY0xZW
[3] Gräfe,JL, Owen, J , Villarreal-Barajas, JE, Khan, R. Characterization of a 2.5 MV inline portal imaging beam. Journal of Applied Clinical Medical Physics 2016 17 222-234.
[4] James L. Gräfe, David R. Chettle, and Fiona E. McNeill. In vivo detection of samarium by prompt gamma neutron activation analysis: a comparison between experiment and Monte-Carlo simulation. J. Anal. At. Spectrom., 2015 30 2441-2448 DOI:10.1039/c5ja00352k
[5] Gräfe JL, McNeill FE, Noseworthy MD, Chettle DR. Gadolinium detection via in vivo prompt gamma neutron activation analysis following gadolinium-based contrast agent injection: a pilot study in 10 human participants. Physiological Measurement 2014 35 1861-1872.
[6] Gräfe, JL, Poirier, Y, Jacso, F, Khan, R, Liu, HW, Villarreal-Barajas, JE. Assessing the divergence from the inverse square law for orthovoltage beams with closed-ended applicators. Journal of Applied Clinical Medical Physics 2014 15 356-366.
[7] Gräfe JL, McNeill FE, Chettle DR, Byun SH. Characteristic X ray emission in gadolinium following neutron capture as an improved method of in vivo measurement: a comparison between feasibility experiment and Monte-Carlo simulation. Nuclear Instruments and Methods in Physics Research Section B 2012 281 21-25.
[8] Chamberlain M, Gräfe JL, Aslam, Byun SH, Chettle DR, Egden LM, Webber CE, McNeill FE. In vivo quantification of bone-fluorine by delayed neutron activation analysis: a pilot study of hand bone-fluorine levels in a Canadian population. Physiological Measurement 2012 33 375-384.
[9] Chamberlain M, Gräfe JL, Aslam, Byun SH, Chettle DR, Egden LM, Orchard GM, Webber CE, McNeill FE. The feasibility of in vivo quantification of bone-fluorine in humans by delayed neutron activation analysis: a pilot study. Physiological Measurement 2012 33 243-257. Featured Article.
[10] Gräfe JL, McNeill FE, Byun SH, Chettle DR, Noseworthy MD. The feasibility of in vivo detection of gadolinium by prompt gamma neutron activation analysis following gadolinium-based contrast-enhanced MRI. Applied Radiation and Isotopes 2011 69 105-111.
[11] Gräfe JL, McNeill FE, Byun SH, Chettle DR, Noseworthy MD. A benchmarked MCNP model of the in vivo detection of gadolinium by prompt gamma neutron activation analysis. Nuclear Instruments and Methods in Physics Research Section B 2010 268 2451-2457.