Nanjing Medical University, China
Zizheng Wang has completed his MD at the age of 35 years from Nanjing Medical University. He is the Director of Nanjing Nuclear Medicine Center, affi lated to Nanjing Medical University. His research was focused on receptor targeted tumor imaging and therapy with specifi c radiotracers such as radiolabelling NOTA-OC, DOTA-OC (somatostatin), RGD peptides (integrin αvβ3), folate analogue or derivants (folate), PSMA targeting peptides (prostate specifi c membrane antigen). He has get patents and tried his best to transform it into clinic. He has published more than 5 papers in reputed journals.
This study was to investigate the value of integrin αvβ3 targeted microPET/CT imaging with 68Ga-DOTA-RGD2 as radiotracer
for the detection of breast cancer osteolytic bone metastases. we prepared 68Ga-DOTA-RGD2 via one-step method. Animal
model with Parathyroid hormone (PTH)–induced osteolysis in the calvarium was established and served as PTH Group (BP).
Biodistribution study of 68Ga-DOTA-RGD2 was carried out in BP. Animals with injection of same volume of saline instead of
PTH was served as Control group (BC). Integrin receptor block study was done with pre-injection of high dose of DOTARGD
2. 68Ga-DOTA-RGD2 and 18F-NaF microPET/CT imaging were perfromed respectively and radiotracer distribution were
compared between BP and BC. Breast cancer osteolyic bone metastases was established via intrcardial injection of breast cancer
cells (MDA-MB 231). 68Ga-DOTA-RGD2 microPET/CT imaging were perfromed for the detection of breast cancer osetolytic
bone metastases. Animals were sacrifi ced and bone lesions were harvested for pathological examination. We found that 68Ga-
DOTA-RGD2 was stable in vitro and its radiopurity was as high as (96.4±2.1)% 3h aft er its preparation. Its blood elimination
was fast while its uptake by the liver and kidneys were relatively low. It was discharged soon aft er its intravenous injection. In
the BP group, regional uptake of 68Ga-DOTA-RGD2 in osteolytic lesion of calvarium (%ID/g) reached peak (5.14±0.65 ) 60 min
aft er tail vein injection. It was signifi cantly more than that in BC group (2.06±0.35，t=7.81，P<0.05). Bone radiotracer uptake
ratio of osteolytic lesion to normal calvrium （O/N）was compared based microPET/CT imaging. Bone O/N of 68Ga-DOTARGD
2 was (6.1±0.97), signifi cantly greater than that of 18F-NaF (1.2±0.33,t=10.17, P<0.05). 68Ga-DOTA-RGD2 microPET/CT
imaging was able to demonstrate the ostelytic bone metastasis in calvarium, thoracic vertebrae and lung metastasis. Th ey were
confi rmed by pathology results. According to our results, 68Ga-DOTA-RGD2, as new integrinαvβ3 receptor targeting radiotracer,
was potential for positive imaging and early detection of oseolytic lesion or breast cancer osteolytic bone metastasis.