中文摘要：

目的 探讨68镓-1,4,7,10-四氮杂环十二烷-1,4,7,10-四乙酸-（精氨酸-甘氨酸-天冬氨酸）2（^68 Ga-DOTA-RGD2）正电子发射显像（microPET）/CT显像探测乳腺癌溶骨性转移的价值.方法 一步法制备^68 Ga-DOTA-RGD2,构建溶骨性骨病变模型（BP组）研究其生物学分布,左心室注射乳腺癌细胞（MDA-MB-231）构建乳腺癌骨转移模型（BM组）,并行^68 Ga-DOTA-RGD2和18F-氟化钠（NaF） microPET/CT显像显像,由病理证实.结果 ^68 Ga-DOTA-RGD2体外稳定,血液、肺及肾脏中清除迅速,肝、脾摄取少且排泄快,甲状旁腺激素（PTH）注射侧颅骨^68Ga-DOTA-RGD2摄取（％ID/g）在尾静脉注射60 min达到峰值（5.14 ±0.65）,显著高于BC组（2.06 ±0.35,t=7.81,P＜0.05）,MicroPET/CT显像示PTH注射侧与对侧顶骨放射性摄取比值^68Ga-DOTA-RGD2（4.57±0.97）明显高于^18F-NaF（1.20±0.33,t=10.17,P＜0.05）,BM组^68Ga-DOTA-RGD2显像可见颅骨、胸椎溶骨性转移灶及肺转移灶呈异常浓聚.结论 ^68 Ga-DOTA-RGD2整合素受体αvβ3靶向显像可早期发现溶骨性骨转移.

英文摘要：

Objective To investigate the value of integrin αvβ3 targeted micro positron emission tomography （microPET）/CT imaging with 68 Ca-1,4,7,10-tetraazacyclododecane-N,N′,N″,N′″-tetraacetic acid-arginine-glycine-aspartate peptide dimer （^68 Ga-DOTA-RGD2） as radiotracer for the detection of breast cancer osteolytic bone metastases.Methods 68 Ga-DOTA-RGD2 was prepared via one-step method at 100 ℃ for 15 min.Animal model with parathyroid hormone （PTH）-induced osteolysis in the calvarium was established and served as PTH group （BP）.Biodistribution study of ^68 Ga-DOTA-RGD2 was carried out in BP.Integrin receptor block study was done with pre-injection of high dose of DOTA-RGD2.^68Ga-DOTA-RGD2 and ^18F-NaF micmPET/CT imaging were perfromed respectively.Breast cancer osteolyic bone metastases was established via intrcardial injection of breast cancer cells.^68 Ga-DOTA-RGD2 microPET/CT imaging were perfromed for the detection of breast cancer osetolytic bone metastases.Animals were sarcrificed and bone lesions were harvested for pathological examination.Results 68 Ga-DOTA-RGD2 was stable in vitro and its radiopurity was as high as （96.4 ± 2.1） % 3 h after its preparation.Its blood elimination was fast while its uptake by the liver and kidneys were relativelylow.It was discharged soon after its intravenous injection.In the BP group,regional uptake of ^68 Ga-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-DOTA-RGD2 was （6.10 ± 0.97）,significantly greater than that of ^18F-NaF （1.20 ±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.Conclusion