[Molecular imaging of epidermal growth factor receptor in glioma-bearing rats].

OBJECTIVE

To investigate the value of 11C-PD153035 as an EGFR imaging agent in C6 tumor-bearing rat.

METHODS

The tumor-bearing rats were generated by subcutaneous injection of glioma C6 cells. Positron emission tomography/computer tomography (PET/CT) scans started as soon as intravenous injection of 11C-PD153035 (15-20 MBq/0.3 ml) was completed, images were collected continuously. The region of interest (ROI) was used to study the percentage of radioactivity in major organs and implanted tumors in the rats. The accumulation and blocking study in vitro was completed.

RESULTS

There were significant differences in 11C-PD153035 uptake among major organs. The maximum uptake in the organs ranked in the following order: liver > gastrointestinal tract > kidney > lung > brain > muscle. Radioactivity could be also observed in the tumors. The radioactivity ratio (T/NT, target/non-target) peaked (4.15) at 40 - 50 min post injection. The in vitro blocking study showed that 11C-PD153035 uptaken by C6 cells could be blocked by PD153035.

CONCLUSION

The results of this study show that 11C-PD153035 can be uptaken by EGFR-expressing tumors. 11C-PD153035 has a potential as a bioprobe to yield useful information for both diagnosis and therapy of tumors. However, the high concentration of 11C-PD153035 in the gastrointestinal tract is unfavorably affecting the tumor detection in these organs.