Objective:To explore the feasibility of diagnosing glioma which expressing high level EGFR by 131I-EGF.Methods: In vitro cellular uptake and cellular retention experiment of

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I-EGF was carried out with C6 cell.Radiodistribution experiment was carried out after injection of

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I-EGF into 2-week-old tumor bearing Wistar rats

at 30min

2 hour

6 hour and 12 hour. SPECT images were carried out after 12 hours of intravenous injection of

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I-EGF between tumor bearing rats and normal rats. Results:The rate of C6 cellular uptake and retention in vitro was high.At all selected time

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I-EGF was mainly distributed in liver

spleen and kidney

partially distributed in tumor

but the radioactivity was stronger and stronger with the time passed

until reached the highest strong at 12h.Tumor tissues of tumor bearing rats were seen clearly by SPECT imaging after 12 hours of intravenous injection of

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I-EGF

the liver and spleen were the major normal organs visualized on the images

and the other tis- sues didn’t be seen obviously.Conclusions:

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I-EGF could offer a new and specific approach to diagnose tumor such as glioma and other tumors expressing high level EGFR from molecular level.