Abstract:
To evaluate an integrin imaging approach based on single photon emission computed tomography(SPECT) by using a technetium-99m(
99Tc
m) labeled dimeric cyclic arginine-glycine-aspartic acid(RGD) analogue(3PRGD
2) as the tracer to target the integrin α
vβ
3 expressed pancreatic cancer. PANC-1 pancreatic cancer cells and tumor tissues were stained with integrin α
vβ
3 to find if it is operatively expressed. PANC-1 pancreatic cancer cells were implanted into the shoulder of BALB/C nude mice to establish a qualified animal model.
99Tc
m-3PRGD
2 was prepared with hydrazine nicotinamide(HYNIC) as a dual functional linker.
99Tc
m-3PRGD
2 whole body planar imaging was performed every 0.5 hours to observe the distribution of the whole body. ROIs(regions of interest) were drawn on the tumor and the healthy side, and the ratios of tumor to background were calculated.
99Tc
m-3PRGD
2 SPECT was performed in 6 patients with pancreatic tumor to evaluate the detection efficiency of pancreatic cancer. Integrin α
vβ
3 is highly expressed in PANC-1 pancreatic cancer cells and tumor tissues. The labeling rate of
99Tc
m-3PRGD
2 is more than 99%. The imaging of tumor bearing mice show that the tumor has a high uptake of the tracer, and the tumor can be seen in 0.5 h p.i., the T/NT reachs the maximum value in 1.5 h p.i., and the tumor can be clearly displayed in 6.0 hours.
99Tc
m-3PRGD
2 SPECT can detect primary pancreatic lesions and liver metastases in 6 patients, with a detection rate of 100%.
99Tc
m-3PRGD
2 imaging is sensitive for the detection of pancreatic cancer, meriting further investigation of
99Tc
m-3PRGD
2 as a novel clinical tracer for integrin receptor imaging.