Development of a positron-sensitive probe for tumor detection

开发用于肿瘤检测的正电子敏感探针

基本信息

批准号：
13670974
负责人：
YAMAMOTO Seiichi
金额：
$ 2.18万
依托单位：
Kobe City College of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

For radio-guided surgery on tumors using F-18-FDG, detection of annihilation gamma photons emanating from other parts of the body produces background radiation counts and limits its use in clinical situations. To overcome this limitation, we have developed an intra-operative positron probe with background-rejection capability. The positron probe uses a phoswich detector composed of a plastic scintillator and a bismuth germinate (BGO). A positron from a positron emitter such as F-18 is detected by the plastic scintillator and emits annihilation photons. The BGO detects one of the annihilation photons while a photo-multiplier tube (PMT) detects scintillation photons from both scintillators. The decay time differences of these two scintillators are used to distinguish whether the event is a true event where a positron, and a following annihilation photon are detected simultaneously, or a background event. In this configuration, only positrons can be selectively detected, even in an environment of high background gamma photon flux. Spatial resolution was 11-mm full width at half maximum (FWHM) 5 mm from the detector surface. Measured sensitivity for the F-18 point source was 2.6 cps/kBq 5 mm from the detector surface. The background count rate was less than 0.5cps for a 20-cm diameter cylindrical phantom containing 37 MBq of F-18 solution measured on the phantom surface, while the positron count rate was almost linear over a range of approximately 6 kcps. These results indicate that our developed intra-operative positron probe is valuable for radio-guided surgery on tumors using F-18-FDG in a high flux of background annihilation gamma photons.

对于使用 F-18-FDG 进行肿瘤的无线电引导手术，检测从身体其他部位发出的湮灭伽马光子会产生背景辐射计数，并限制其在临床情况下的使用。为了克服这一限制，我们开发了一种具有背景抑制能力的术中正电子探针。正电子探测器使用由塑料闪烁体和萌发铋（BGO）组成的磷光探测器。来自正电子发射器（例如 F-18）的正电子被塑料闪烁体检测到并发射湮灭光子。 BGO 检测其中一个湮灭光子，而光电倍增管 (PMT) 检测来自两个闪烁体的闪烁光子。这两个闪烁体的衰减时间差用于区分该事件是同时检测到正电子和随后的湮灭光子的真实事件还是背景事件。在这种配置中，即使在高背景伽马光子通量的环境中，也只能选择性地检测到正电子。距离探测器表面 5 毫米处的空间分辨率为 11 毫米半高全宽 (FWHM)。距探测器表面 5 毫米处测得的 F-18 点源灵敏度为 2.6 cps/kBq。对于在体模表面测量的含有 37 MBq F-18 溶液的 20 厘米直径圆柱形体模，背景计数率小于 0.5cps，而正电子计数率在大约 6 kcps 的范围内几乎呈线性。这些结果表明，我们开发的术中正电子探针对于在高通量背景湮灭伽马光子中使用 F-18-FDG 对肿瘤进行无线电引导手术很有价值。