PT - JOURNAL ARTICLE AU - Jae Ho Jung AU - Byung Chul Lee AU - Byung Seok Moon AU - Ho-Young Lee AU - Se Joon Woo AU - Seong Joon Ahn AU - Duck Jin Hwang AU - Kyu Hyung Park AU - Ji Hyun Park AU - Sang Eun Kim TI - In vivo imaging of angiogenesis in a mouse model of laser-induced choroidal neovascularization using a novel <sup>99m</sup>Tc-labeled RGD peptide <sup>99m</sup>Tc-IDA-D-[c(RGDfK)]<sub>2</sub> DP - 2013 May 01 TA - Journal of Nuclear Medicine PG - 1214--1214 VI - 54 IP - supplement 2 4099 - http://jnm.snmjournals.org/content/54/supplement_2/1214.short 4100 - http://jnm.snmjournals.org/content/54/supplement_2/1214.full SO - J Nucl Med2013 May 01; 54 AB - 1214 Objectives Integrin αvβ3 is preferentially increased on neovascular endothelial cells and is involved in ocular angiogenesis. In this study, we evaluated the angiogenic activity of choroidal neovascularization (CNV) by 99mTc-IDA-D-[c(RGDfK)]2 SPECT imaging in the mouse model of laser-induced CNV. Methods 99mTc-IDA-D-[c(RGDfK)]2 was synthesized by incorporating [99mTc(CO)3]+ into the precursor (IDA-D-[c(RGDfK)]2). Male C57Bl/6 mice ( n=5), 10 weeks old, were treated with five spots of retinal argon laser coagulation to the right eye to make defect in the Bruch’s membrane (100 mW, 50 ms, 50 μm). Mice were intravenously injected 99mTc-IDA-D-[c(RGDfK)]2 (18.5 MBq). Images of 99mTc-IDA-D-[c(RGDfK)]2 was obtained at a mid-scan time of 25 min, for scan duration of 10 min in each mice at different days after laser irradiation (1, 3, 7, and 14 days). Regional alterations in 99mTc-IDA-D-[c(RGDfK)]2 uptake were measured from the images created by ROI using an animal SPECT/CT. The choroidal tissue was dissected for immunohistochemistry study. To evaluate the statistical significance, Wilcoxon test was done. Results The overall radiochemical yield of radiotracer after HPLC purification was 72-79%. We compared the count of right (R) eye and left (L) eye after laser irradiation. Between right and left eye, the radio-uptake count of right eye was significantly higher than that of left at different days (R/L ratio = 1.51 at day 1; 1.50 at day 3; 13.7 at day 7; 5.2 at day 14, p&lt;0.05). All the right eyes had CNV lesions by immunohistochemistry. Conclusions Our results indicates that 99mTc-IDA-D-[c(RGDfK)]2 demonstrates visible SPECT uptake in choroidal neovascularization, which may make it a promising radiotracer for evaluating the angiogenic activity of choroidal neovascularization in vivo and for development of therapeutic modalities.