EVALUATION OF THERAPEUTIC EFFECT BY POSITRON EMISSION TOMOGRAPHY USING FLUORINATED THYMIDINE DELIVATIVE

我们首先评估了^&lt；18&gt；F-flt在小鼠体内的生物分布。除了在移植瘤中高摄取外，Flt还聚集在刀豆蛋白A刺激激活的淋巴细胞中。对40例脑肿瘤和其他恶性肿瘤患者进行了临床评估(53次检查)。给予知情同意的患者给予静脉注射Flt。40min后用发射扫描和3min透射式扫描获得脑部图像，50min后用3min发射和1min透射式扫描获得人体图像，共5~6帧。在肿瘤上设置感兴趣区，测量摄取半定量数值(SUV)，并与组织学诊断进行比较。脑肿瘤摄取Flt反映了肿瘤的恶性程度，随着胶质瘤分级的增加，肿瘤摄取增加。恶性淋巴瘤和转移性脑瘤的摄取率也在恶性胶质瘤的范围内。脑肿瘤的SUV与细胞增殖标记物MIB-1的表达呈正相关。在疑似脑肿瘤复发的病例中，Flt-PET能准确地检测出部分患者的恶性转化复发病灶，而在良性复发肿瘤和肉芽肿性病变中，Flt摄取假性高；对于躯干恶性肿瘤，肺癌和胰腺癌的Flt摄取较高。对10名患者进行疗效评估是可能的。除2例恶性淋巴瘤患者治疗前摄取较低外，其余患者治疗后或治疗后早期摄取均下降，提示Flt-PET可用于早期预测疗效。

We first evaluated the biodistribution of ^<18>F-FLT in mice. In addition to high uptake in xenografted tumor, FLT was shown to accumulate in lymphocytes activated by Concanavalin A stimulation.Clinical evaluation was conducted for 40 patients with brain tumors and other malignant tumors (53 examinations). Patients, who gave informed consent, were given intravenous injection of FLT. Image of the brain was obtained 40 minutes later by 20-min emission scan and 3-min transmission scan, and image of the body was obtained 50 min later by 3-min emission and 1-min transmission scan for 5 to 6 frames. Region of interest was set on the tumor and semi-quantitative value of uptake (SUV) was measured and compared with histological diagnosis.Uptake of FLT in brain tumors reflected the malignant grade of the tumor, and the FLT uptake in the tumor increased as the grade of the glioma increased. Uptakes in malignant lymphoma and in metastatic brain tumor were also in the range of malignant glioma. SUV of brain tumor showed positive relationship with the expression of cell proliferation marker, MIB-1.In cases, where recurrence of brain tumor was suspected, FLT-PET could detect malignant-transformed recurrent lesion correctly in some patients, while in other cases, spuriously high FLT uptake was observed in benign recurrent tumors and in granulomatous lesion.As for malignant tumors of the body trunk, high FLT uptake was observed for lung and pancreatic cancers. Evaluation of treatment effect was possible for 10 patients. Except for 2 patients with malignant lymphoma, showing low initial uptake, FLT uptake decreased during or early post-treatment, showing the possibility of FLT-PET for early prediction of treatment effect.