Imaging of osteolytic bone metastasis from breast cancer with new integrin αvβ3 receptor targeted radiotracer: 68Ga-DOTA-RGD2

4^th World Congress on Cancer Science & Therapy

October 20-22, 2014 DoubleTree by Hilton Hotel Chicago-North Shore Conference Center, USA

Zizheng Wang

Scientific Tracks Abstracts: J Cancer Sci Ther

Abstract :

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 sacrificed 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 after its preparation. Its blood elimination was fast while its uptake by the liver and kidneys were relatively low. It was discharged soon after 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 after tail vein injection. It was significantly 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), significantly 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. They were confirmed 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.

Biography :

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, affilated to Nanjing Medical University. His research was focused on receptor targeted tumor imaging and therapy with specific radiotracers such as radiolabelling NOTA-OC, DOTA-OC (somatostatin), RGD peptides (integrin αvβ3), folate analogue or derivants (folate), PSMA targeting peptides (prostate specific 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.