Study of three-dimensional positron emission tomography for wholebody evaluation of malignant tumor

我们使用F-18标记的氟-2-脱氧葡萄糖（FDG）进行了三维正电子发射断层扫描（3D-PET）的基础和临床研究，用于恶性肿瘤的全身评估。在1997年研究结果的基础上，确定了合适的3D-PET检测方法，F-18 FDG注射剂量为111 ~ 185 MBq，移动床位重复7 ~ 8次数据采集（每次2min）。与常规2D-PET相比，注射剂量不到一半，采集时间缩短了一半左右。我们对肺癌、前列腺癌、头颈部肿瘤等患者进行评估。在3D-PET全身图像上，恶性肿瘤清晰可见为热病灶。使用F-18 FDG的3D-PET具有无创性，可以检测到既往检查未发现的转移性病变，因此对恶性肿瘤的全身筛查非常有用。本次使用F-18 FDG的3D-PET检查将在福井医科大学医院作为一项高度先进的医疗手段应用于患者。但是，由于正常脑组织中也有F-18 FDG的积累，3D-PET结合F-18 FDG并不像MRI那样适用于脑转移病灶的检测。在基础研究中，通过对采集场外散射分数的校正，可以在3D-PET上正确地实现区域放射性的定量。由于本研究使用的正电子相机无法获得3D模式的透射扫描，因此无法在患者研究中进行定量评估的衰减和散射校正。为了在全身3D-PET中获得定量结果，需要能够同时发射和传输数据采集的正电子相机。

We undercarried basic and clinical studies of three-dimensional positron emission tomography (3D-PET) using F-18 labeled fluoro-2-deoxyglucose (FDG) for wholebody evaluation of malignant tumors. On the basis of research results in 1997, suitable examination method of 3D-PET was determined that injection dose of F-18 FDG was 111-185 MBq, data acquisition (2min each) was repeated 7-8 times moving the bed position. In comparison with conventional 2D-PET,injection dose was less than a half, and acquisition time was shortened about a half. We evaluated patients with lung cancer, prostatic cancer, head and neck tumors and so on. Malignant tumors were clearly visualized as hot lesions on 3D-PET wholebody images. 3D-PET using F-18 FDG was non-invasive and could detect metastatic lesions which were not found with previos examinations, therefore, it was concluded to be very useful for wholebody screening of malignant tumors. This 3D-PET examination using F-18 FDG will be applied to patients as a highly advanced medical treatment in Fukui Medical University Hospital. However, 3D-PET with F-18 FDG was not so suitable for the detection of metastatic lesions in the brain as MRI,since normal brain tissue also accumulated F-18 FDG.In basic study, quantitation of regional radioactivity could be correctly achieved on 3D-PET by the correction of scatter fraction from outside of acquisition field. Since the positron camera used in this study could not acquire transmission scan in 3D mode, attenuation and scatter correction for quantitative assessment could not be performed in patient studies. In order to obtain quantitative results in wholebody 3D-PET,positron camera capable to simultaneous emission and transmision data acquisition should be necessory.