THERMOSYPHON TARGETRY TO IMPROVE F-18 PET

描述(由申请人提供)： 拟议工作的总体目标是降低用于正电子发射断层扫描(PET)的加速器生产的F-18放射性药物的成本。正电子发射断层扫描是一种由医疗保险报销的核医学代谢成像设备，用于诊断、分期和重新分期10种癌症适应症。每年的PET扫描(350,000+)正在迅速增加，但CMS的PET扫描报销从2004年的1774美元下降到2005年的1371美元，降幅为23%。总成本的20%是放射性药物剂量的F-18氟脱氧葡萄糖(FDG)。因此，聚酯使用量的持续增长将受益于生产FDG的成本的降低。这个项目的目标是通过使用我们的发明-热虹吸靶，将每剂量的成本降低2倍，它可以去除两倍于目前靶技术1千瓦限制的质子束热量。去除更多热量可以充分利用PET回旋加速器安装基地中的可用质子束电流，从而至少将FDG用O-18(p，n)F-18的产量增加一倍(通过使用正离子杜克大学PET设施回旋加速器的27 MeV质子束进行第一阶段原型目标实验确定了可行性)。在第一阶段设计和建造了另外两个热虹吸靶，为在第二阶段在其他加速器(其中一个的束流功率为9千瓦)测试其热极限做准备。这项拟议的高功率目标工程正在开辟新的天地，n阶段研究可能不得不解决以前从未遇到过的困难技术问题。第二阶段目标1是束流测试，以确定在第一阶段建造的两个能量分别为16和30 MeV的负离子质子回旋加速器的原型的热极限。目标2是将测试结果与预测的热工水力模型相关联，以改进设计。目标3正在开发材料科学技术，在高导热靶体材料(铜、银)上涂覆化学惰性难熔金属(Ta、Nb)，以适应高束功率，同时保持可行的标记化学。目标4正在开发从热虹吸管设计中回收F-18氟离子的有效方法。目标5正在应用以前的目标的结果来建造和测试更多的改进原型。目标6是设计和演示适用于广泛商业用途的可靠的高性能目标系统。AIM 7正在应用热工水力模型来确定性能包络，以指导各种加速器的目标系统设计。第三阶段的目标是使这项技术可用于改造合适的现有加速器(目前估计为70台)，并供新回旋加速器制造商使用，从而将F-18 FDG的成本降低两倍或更多，从而将PET扫描总成本降低约10%。

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 two through the use of our invention called the thermosyphon target, which can remove twice as much proton beam heat as the one kilowatt limit of present target technology. Removing more heat allows full use of the available proton beam current in the installed base of PET cyclotrons, thus at least doubling the production of O-18(p,n)F-18 for FDG (feasibility established by Phase I prototype target experiments using the 27 MeV proton beam of the positive-ion Duke University PET Facility cyclotron). Two additional thermosyphon targets were designed and built in Phase I as preparation for testing to their thermal limits in Phase II at other accelerators (one with beam power of nine kilowatts). This proposed high power target engineering is breaking new ground, and Phase n research may have to address difficult technical problems not previously encountered. Phase II aim 1 is beam testing to determine the thermal limits of the prototypes built in Phase I for two negative-ion proton cyclotrons with energies of 16 and 30 MeV. Aim 2 is correlating test results with predictive thermohydraulic models to design improvements. Aim 3 is developing material science technology to coat high thermal conductivity target body materials (Cu, Ag) with chemically inert refractory metals (Ta, Nb), in order to accommodate high beam power while maintaining viable labeling chemistry. Aim 4 is developing efficient methods of recovering F-18 fluoride ion from thermosyphon designs. Aim 5 is applying results of the previous aims to build and test additional improved prototypes. Aim 6 is the design and demonstration of a reliable high-performance target system suitable for widespread commercial use. Aim 7 is applying the thermohydraulic models to determine performance envelopes to dictate target system designs for a variety of accelerators. The goal of Phase III is to make this technology available for retrofit to appropriate existing accelerators (currently estimated at 70) and for use by manufacturers of new cyclotrons, thus implementing cost reduction of F-18 FDG by a factor of two or more to reduce total PET scan costs about 10%.