Progress toward full development of ViewRay's Renaissance" System 1000 MRI image guided radiation therapy (IGRT) system is being threatened by the growing shortage of helium worldwide. This pioneering technology is aimed at treating cancerous tumors in the abdomen where bodily functions cause significant organ displacements making precise dose delivery difficult or impossible. Liquid helium is presently essential for operation of present day low temperature niobium-titanium (NbTi) based superconductor magnets. Helium worldwide is being depleted at a rate exceeding the capacity of the current natural gas wells (helium is a byproduct of some natural gas wells) around the world. The US strategic reserves are being sold off to stabilize the price but to little avail;the price of helium continues to rise. Projections from a variety of sources all point to major shortages and the price increases in the 2010-2015 time frame and beyond. This will threaten all helium users but most of all the MRI industry. Already, the three major MRI manufacturers, have development programs aimed at converting from re-condensing liquid helium bath cooling to dry conduction cooling to cryocoolers using magnesium diboride (MgB2) superconductors. Hyper Tech has active programs with all three to utilize magnesium diboride (MgB2) superconductors. Magnesium diboride superconductors have the unique property of being superconducting a full 30 K higher than the currently used niobium titanium (NbTi) while being in the same wire form suitable for large magnet manufacturing. MgB2 enables converting from the liquid helium bath cooling to conduction cooling because of this wide temperature margin needed to accommodate temperature gradients in the magnet. Even without the urgency brought on by the helium shortage, it is cost effective to all MRI manufacturers to transition their background magnets from liquid helium bath cooling to dry conduction cooling. With an inventory of ~2000 liters of liquid helium in a standard NbTi based MRI magnet, there is the ever present danger of a quench and sudden release of gaseous helium. A rupture disc and large exhaust duct to the outside are required for all present MRI installations. In addition, the dewar and vacuum enclosure must be ASME pressure vessel certified in case of an over pressure due to a failed rupture disc. These factors make a significant cost impact on the initial price of an MRI and the follow-on maintenance. This Phase I, Phase II Fast Track SBIR endeavors to remove the helium shortage obstacle facing ViewRay's development while at the same time providing an avenue to significantly lower the unit cost of their commercialized Renaissance" System 1000. During this program Hyper Tech will perform the necessary research in order to develop and fabricate a helium free background magnet system using its MgB2 superconductor wire. We will supply the magnet system to ViewRay who will incorporate it into their Renaissance" System 1000 MRI IGRT system and perform imaging tests to verify the overall magnet system performance compared with the present NbTi superconducting magnet based imaging system. This will lead to clinical validation of the fully integrated IGRT with Hyper Tech's MgB2 based background magnet system.
The first true, real time MRI image guided radiation therapy (IGRT) system that delivers gamma radiation to malignant tumors with pinpoint accuracy in spite of organ movement will be demonstrated by ViewRay Renaissance" System 1000 using Hyper Tech's magnesium diboride superconducting magnets. The Hyper Tech MgB2 magnet system will significantly lower the cost and on-going maintenance costs of ViewRay's cancer treatment technology. In addition, the magnet system will be safer and less prone to quenching than presently used magnet system.