October 31, 2014 at 3:40 pm

Physics Colloquium: Radionuclide TRICKs for Cancer Diagnosis OR TREATment, Oct. 31

Suzanne Lapi

Suzanne Lapi

The Physics & Astronomy Colloquium Series presents Suzanne Lapi of the Washington University in St. Louis on “Radionuclide TRICKs for Cancer Diagnosis OR TREATment” on Friday, Oct. 31, at 4:10 p.m. in Walter 245.

Abstract:  Nuclear science and radiochemistry have historically played a major role in the field of medical imaging. While radioisotopes such as 99mTc and 111In were used early on in the development of Single Photon Emission Computed Tomography agents, radioisotopes for Positron Emission Tomography (PET) imaging are becoming more widely used. The production and purification of longer-­‐lived position emitting radiometals has been explored to allow for nuclear imaging agents based on peptides, antibodies and nanoparticles. These
isotopes (64Cu, 89Zr, 86Y) are typically produced via irradiation of solid targets on smaller medical cyclotrons (<20 MeV) at dedicated facilities. Radiometal production starts with preparation of the target material on a suitable support for cyclotron bombardment. This may be an electroplated deposit, pressed powder pellet, or a foil placed in a suitable holder. Following irradiation of the targets, the radionuclide of interest is separated from the target material by chemical processing.

Our group has developed remote semi-­‐automated systems for the purification of these isotopes and is currently supplying over 20 additional sites for both preclinical and clinical studies. In particular, the use of monoclonal antibodies (mAbs) as molecular targets for tumor cells is a very rapidly expanding pharmaceutical area and 89Zr (t1/2 = 3.3 d) is ideally matched to image the biodistribution of intact antibodies (immunoPET).

For example, our group has focused on the use of radiolabeled antibodies for imaging of HER2 expression in preclinical models and more recently, in a clinical trial. These companion diagnostics can assist in individualized treatment strategies and ultimately lead to better patient outcomes. Recently, isotope harvesting from heavy ion accelerator facilities has also been suggested. The Facility for Rare Isotope Beams (FRIB) will be a new national user facility for nuclear science to be completed in 2020. Radioisotopes could be produced by dedicated runs by primary users or may be collected synergistically from the water in cooling-­‐loops for the primary beam dump that cycle the water at flow rates in excess of hundreds of gallons per minute.

A liquid water target system for harvesting radioisotopes at the National Superconducting Cyclotron Laboratory (NSCL) was designed and constructed as the initial step in proof-­‐of-­‐principle experiments to harvest useful radioisotopes in this manner.

This talk will provide an overview of isotope production using both dedicated machines and harvesting from larger accelerators typically used for nuclear physics.

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