摘要
目的:研究99mTc标记的生长抑素类似物(somatostatin analogues,SSA)99mTc-6-肼基烟酰基-[Tyr3[-Octreotate(99mTc-HYNIC-TOCA)在肿瘤动物模型体内的生物学特性,并与99mTc-P829对比,探讨其用于肿瘤诊断的可行性。方法:以HYNIC为双功能螯合剂(bifunctional chelator,BFC),乙二胺-N?熏N’-二乙酸(EDDA)和三(羟甲基)甲基甘氨酸(Tricine)为协同配体进行TOCA的99mTc标记;以99mTc-HYNIC-TOCA和99mTc-P829为显像剂,对荷人类小细胞肺癌裸鼠进行显像,通过感兴趣区(ROI)技术进行半定量分析,计算并比较两种显像剂的靶/非靶(T/NT)比值;在昆明鼠体内进行动态生物学分布实验,测定并比较不同时点两种显像剂在各脏器的克组织百分摄取率(%ID/g)。结果:99mTc-HYNIC-TOCA的放化纯可达94.2%,室温放置6h后放化纯仍为93.5%;荷瘤小鼠体内,99mTc-HYNIC-TOCA和99mTc-P829主要浓聚于肾脏和肿瘤部位。早期显像中,99mTc-HYNIC-TOCA组肿瘤与对侧比值(T/C)均高于99mTc-P829组;4h时平面显像中T/C达到最高,分别为7.45±0.40和5.71±0.69。昆明鼠体内,两种显像剂在肾脏的摄取率最高,血液半清除时间均小于60min;肝脏对99mTc-P829的最大摄取率明显高于99mTc-HYNIC-TOCA(t=2.17,P<0.05)。结论:99mTc-HYNIC-TOCA和99mTc-P829均具有肿瘤摄取高和血液清除快的良好生物学特性,在高表达SSTR肿瘤的定位诊断中有良好的应用前景。
Abstract
Objective: To study and to compare the biological characteristic of 99mTc labeled somatostatin analogue 99mTc-HYNIC-TOCA with 99mTc-P829 in tumor model, and to discuss the possibility of diagnosing tumors with 99mTc-HYNIC-TOCA. Methods: TOCA was labeled with 99mTc using HYNIC as bifunctional chelator, EDDA and tricine as coligand. The nude mice bearing human small cell lung cancer underwent static whole body planar imaging after the injection of 99mTc-HYNIC-TOCA or 99mTc-P829. ROIs were drawn and the radioactivity ratios of target to non-target(T/NT) were calculated in every planar imaging. The dynamic biodistribution study was operated in Kunming mice and the percent uptake ratios(%ID/g) of two imaging agents in different tissue at different time were measured. Results: The radiochemical purity of 99mTc-HYNIC-TOCA could reach 94.2% and keep to 93.5% after 6h at room temperature. In the images of tumor bearing mice, two imaging agent were both mainly concentrated in kidney and tumor. In early images, the ratios of tumor to contralateral limbs(T/C) in 99mTc-HYNIC-TOCA group were higher than which in 99mTc-P829 group. The greatest ratios of T/C in two groups(7.45±0.40 and 5.71±0.69) were gained until 4h post-injection. In Kunming mice, the %ID/g of kidney in both groups were the highest and the half-clearance time in blood were less than 60min. The uptake ratio of 99mTc-P829 in liver was significantly greater than the ratio of 99mTc-HYNIC-TOCA(t=2.17, P<0.05). Conculusion: 99mTc-HYNIC-TOCA and 99mTc-P829 could be highly uptaken in tumor and quickly cleared from blood. Both of these two imaging agents have good prospect in diagnosing tumors with SSTR expression.
关键词
肿瘤 /
受体 /
生长抑素 /
放射性核素显像
Key words
neoplasms /
receptors /
somatostatin /
radionuclide imaging
孙 逊;安 锐;李 烁;何 勇;伍 军;张 军.
生长抑素受体显像剂99mTc-HYNIC-TOCA和99mTc-P829在肿瘤模型中的对比研究[J]. 中国临床医学影像杂志. 2006, 17(8): 438-443
SUN Xun;AN Rui;LI Shuo;HE Yong;WU Jun;ZHANG Jun.
Comparative study of the somatostatin receptor imaging agent-99mTc-HYNIC-TOCA and 99mTc-P829 in tumor model[J]. Journal of China Clinic Medical Imaging. 2006, 17(8): 438-443
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