Yamamoto Seiichi, Higashi Tatsuya, Senda Michio
Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673, Japan.
Radiol Phys Technol. 2013 Jul;6(2):293-8. doi: 10.1007/s12194-012-0198-6. Epub 2013 Jan 3.
A Gd2SiO5 (GSO) tweezers-type coincidence detector was developed and tested for tumor detection in procedures such as (18)F-fluorodeoxyglucose (FDG)-guided surgery. The detector consists of a pair of GSO scintillators, a pair of metal-packaged small-sized photomultiplier tubes (PMTs), and a coincidence circuit. Because the GSO scintillators are located on the tips of tweezers, a target organ such as a lymph node or the colon can be easily positioned between them. The size of a single GSO was 8 × 14 × 14 mm. The results show that the energy resolution was 30 % full-width at half-maximum (FWHM) and the timing resolution was 6 ns FWHM for 511-keV gamma photons. The point-spread function perpendicular to the detector was 4.5 mm FWHM, and the point-spread function parallel to the detector was 7.5 mm FWHM. The absolute sensitivity of the coincidence detector was 0.6% at the center of the detector when the two GSOs were 5 mm apart. Background counts due to the accidental and scatter coincidence were 2 cps up to 48 MBq from the positron source contained in a 20-cm-diameter, 20-cm-high cylindrical phantom. From these results, we conclude that the proposed tweezers-type coincidence detector is useful for tumor detection by the use of FDG, such as that in radio-guided surgery.
开发了一种硅酸钆（GSO）镊子型符合探测器，并在诸如（18）F-氟脱氧葡萄糖（FDG）引导手术等程序中对其进行肿瘤检测测试。该探测器由一对GSO闪烁体、一对金属封装的小型光电倍增管（PMT）和一个符合电路组成。由于GSO闪烁体位于镊子尖端，淋巴结或结肠等目标器官可轻松置于它们之间。单个GSO的尺寸为8×14×14毫米。结果表明，对于511千电子伏特的伽马光子，能量分辨率为半高宽（FWHM）的30%，时间分辨率为FWHM的6纳秒。垂直于探测器的点扩散函数为FWHM的4.5毫米，平行于探测器的点扩散函数为FWHM的7.5毫米。当两个GSO相距5毫米时，符合探测器在探测器中心的绝对灵敏度为0.6%。在直径20厘米、高20厘米的圆柱形体模中，来自正电子源的偶然和散射符合导致的本底计数在48兆贝可以下为2计数每秒。根据这些结果，我们得出结论，所提出的镊子型符合探测器可用于利用FDG进行肿瘤检测，如在放射性引导手术中。
