Ercan M T, Aras T, Unlenen E, Unlü M, Unsal I S, Hasçelik Z
Department of Nuclear Medicine, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
Nucl Med Biol. 1993 Oct;20(7):881-7. doi: 10.1016/0969-8051(93)90155-n.
Citric acid was labeled with 99mTc with an efficiency of > 99%. The biodistribution of 99mTc-citrate was studied in mice with turpentine-induced abscesses in comparison to 67Ga-citrate. The max. abscess/muscle concentration ratios were 4.61 +/- 1.92 (3 h) for 99mTc-citrate and 4.76 +/- 2.04 (4 h) for 67Ga-citrate. Arthritis was induced in 10 rabbits by intra-articular injection of ovalbumin Scintigrams obtained 4 days later and at 3 h post-injection of 99mTc-citrate showed increased activity involving the synovium. The max. arthritic/contralateral knee ratio was 3.19 +/- 1.29 (3 h) and 6.47 +/- 3.71 (24 h) for 99mTc- and 67Ga-citrate, respectively. The blood clearance curve of 99mTc-citrate in rabbits was biexponential with a fast (T1/2 = 36 min) and a slow (T1/2 = 18 h) component, compared to mono-exponential clearance of 67Ga-citrate (T1/2 = 23 h). In 10 patients with rheumatoid arthritis whole-body scintigrams and spot images of involved joints indicated localization of the tracer in inflamed tissues. The mean target-to-soft tissue ratios were 3.04 +/- 0.81 and 4.95 +/- 2.56 for 99mTc-citrate and 99mTc-MDP, respectively. Renal clearance of radioactivity was evident from the scintigrams. Our results demonstrated that 99mTc-citrate is effective as a radiopharmaceutical for the visualization of inflammatory lesions and may be preferred to 67Ga-citrate due to the ideal physical characteristics of the radionuclide, easy preparation, low cost, early accumulation and the preference for the renal route of excretion.
柠檬酸用99mTc标记，标记效率>99%。与67Ga - 柠檬酸盐相比，研究了99mTc - 柠檬酸盐在松节油诱导脓肿小鼠体内的生物分布。99mTc - 柠檬酸盐的最大脓肿/肌肉浓度比在3小时时为4.61±1.92，67Ga - 柠檬酸盐在4小时时为4.76±2.04。通过关节内注射卵清蛋白在10只兔子中诱发关节炎。4天后获得的闪烁图以及在注射99mTc - 柠檬酸盐后3小时显示滑膜部位活性增加。99mTc - 柠檬酸盐和67Ga - 柠檬酸盐的最大关节炎/对侧膝关节比值分别在3小时时为3.19±1.29和24小时时为6.47±3.71。与67Ga - 柠檬酸盐的单指数清除（T1/2 = 23小时）相比，兔子体内99mTc - 柠檬酸盐的血清除曲线为双指数，有一个快速成分（T1/2 = 36分钟）和一个缓慢成分（T1/2 = 18小时）。在10例类风湿性关节炎患者中，全身闪烁图和受累关节的局部图像显示示踪剂在炎症组织中定位。99mTc - 柠檬酸盐和99mTc - MDP的平均靶组织与软组织比值分别为3.04±0.81和4.95±2.56。放射性核素的肾清除在闪烁图中很明显。我们的结果表明，99mTc - 柠檬酸盐作为一种放射性药物对于炎症病变的显像是有效的，并且由于放射性核素具有理想的物理特性、易于制备、成本低、早期聚集以及更倾向于经肾排泄途径，可能比67Ga - 柠檬酸盐更具优势。
