REGENERATIVE TURBINE TARGETRY TO IMPROVE F-18 PET

DESCRIPTION (provided by applicant): The overall objective of the proposed work is to reduce the cost of accelerator produced F-18 radiopharmaceuticals used in Positron Emission Tomography (PET), a Medicare-reimbursed nuclear medicine metabolic imaging modality used to diagnose, stage, and restage ten cancer indications. Annual PET scans (350,000+) are rapidly increasing, but CMS reimbursement for PET scans is decreasing 23% from $1774 in 2004 to $1371 in 2005. Twenty percent of the total cost is the radiopharmaceutical dose of F-18 fluorodeoxy glucose (FDG). Sustaining growth in the use of PET will thus benefit from reducing the cost of producing FDG. The goal of this project is to lower cost per dose by a factor of 4-10 through use of a novel target invention accomplishing very high beam heat removal rates. Removing more heat allows use of high proton beam currents to produce the nuclear reaction O-18(p,n)F-18 to make F-18 fluoride ion for synthesis of FDG. Two commercial cyclotron manufacturers (Ion Beam Applications and Advanced Cyclotron Systems) use external injection ion sources that permit external beam currents of 300-500 microamps, and thus beam power of 9-15 kilowatts. Current technology F-18 production targets capable of removing only about one kilowatt of heat, cannot take advantage of these high performance accelerators. Phase I experiments at Duke University utilized our patented miniature regenerative turbine pump and novel heat exchanger to achieve rapid recirculation at low target water pressures through a cyclotron target, establishing the feasibility of removing well above three kilowatts of heat if higher pressures are used. A cyclotron which will produce beam power of nine kilowatts has been identified for Phase n testing. Aim 1 is installing the Phase I target system on this accelerator, and operating at higher pressures to determine the thermal limit. Aim 2 is correlating these results with predictive thermohydraulic models for designing improved prototypes. Aim 3 is developing an optimum heat exchanger. Aim 4 is designing an optimized regenerative turbine pump with magnetic drive. Aim 5 is developing effective methods of recovering F-18 by sidestream extraction and/or batch methods. Aim 6 is to apply results from previous aims to design, build and test improved prototypes combining target, regenerative turbine pump, and heat exchanger in one compact assembly. Aim 7 is the design and demonstration of a reliable high-performance system suitable for widespread use. Aim 7 is thermohydraulic modeling to determine performance envelopes. The goal of Phase 3 is to make this technology available to appropriate commercial accelerators, thus implementing the overall goal of lowering the cost of PET scans by up to 15% by sienificantlv reducing the cost of oroducine FDG and other F-18 labeled radiopharmaceuticals.