James Gräfe, PhD, MCCPM
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).
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 investigating the potential to image a gadolinium-based contrast agent during proton therapy by neutron activation. More details can be found here: http://www.sciencedirect.com/science/article/pii/S0168583X17306080
In vivo detection of rare earth elements: The use of rare earth elements (REE) is increasing in popularity in both industry and medicine. However, it is often thought that these metals in their free form can be toxic and cause fibrosis, calcium deposition, inflammation, and necrosis to a variety of different organs and tissues. In contrast to this thinking, there is some evidence to suspect a therapeutic effect on bone health from these elements. 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, while other lanthanum based agents have recently been proposed as therapeutic agents for bone resorption disorders. 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. This work links trace element concentration with biological effects and/or benefits.
Our latest work was featured on medicalphysicweb: http://medicalphysicsweb.org/cws/article/research/70084