Comparative Study of _(99m)TcN(NOEt)_2 and ^(99m)Tc-MIBI Imaging in Mice Bearing Ehrlich Ascites Tumor

Objective To evaluate and compare the ability to detect tumor by bis (N-ethoxy-N-ethyl dithiocarbamato) nitrido99mTc(V) [99mTcN(NOEt)2] and99mTc hexakis-2- methoxyisobutyl isonitrile [99mTc-MIBI]. Methods 99mTcN(NOEt)2 was prepared and quality control was performed using ascending thin-layer chromatography. Four mice bearing Ehrich ascites tumor cells underwent whole body planar imaging at 30 min, 2 h and 4 h after injection of99mTc-MIBI or99mTcN(NOEt)2. ROIs were drawn around the tumor, head, chest, and contralateral limbs in whole body planar images, and ratios of radioactivity in tumor in head (T/H), chest (T/C), and contralateral limbs (T/L) were calculated. The mice of99mTcN (NOEt)2 group were killed, then blood was collected, and the tumor and organs were excised, weighed and the radioactivity was measured. Results 99mTcN(NOEt)2 was stable after 4h at the room temperature.99mTcN(NOEt)2 was delivered to the tumor selectively and efficiently.99mTcN(NOEt)2 was found to provide excellent tumor-to-nontumor contrast for all the tissue except the abdomen. The T/L ratios increased to their maximums (4.87) at 2 h after injection. There was significant difference between the99mTcN(NOEt)2 imaging group and99mTc-MIBI imaging group. In vitro the radioactivity ratios per unit weight of tumor to blood, muscle, skeleton, lung, heart, and spleen were much higher than those of tumor to liver, instestine. Conclusion In mice bearing Ehrich ascites tumor,99mTcN(NOEt)2 exhibits a set of features essential for a good tracer for tumor imaging, including a rapid washout from blood, high uptake rate in tumor tissue, prolonged retention and high tumor-to-nontumor uptake ratio. The imaging quality of99mTcN(NOEt)2 was superior to that of99mTc-MIBI. These features indicate that99mTcN(NOEt)2 may be a better tracer to detect tumor than99mTc-MIBI. Key words tumor - radionuclide imaging - NOEt - MIBI

头颈部肿瘤^(99m)Tc-MIBI阳性显像的临床研究

目的:探讨99mTc-MIBI亲肿瘤显像在头颈部肿瘤定性诊断中的应用价值。方法:91例临床初诊为头颈部肿瘤的患者和20例正常志愿者行早期和延迟99mTc-MIBI头颈部断层显像。结果:99mTc-MIBI早期/延迟显像诊断头颈部恶性肿瘤的总体敏感度、特异度、准确度及阳性预测值分别为78.7%/72.3%、72.1%/88.4%、75.6%/80.0%和75.5%/87.2%;鼻咽癌、非霍奇金淋巴瘤显像效果优于上颌窦癌9。9mTc-MIBI显像对于鼻咽癌复发/残留以及鼻腔非霍奇金淋巴瘤定性诊断价值明显优于CT和MRI。结论:99mTc-MIBI亲肿瘤显像在头颈部肿瘤的定性诊断中有较好的应用前景。