RT Journal Article SR Electronic T1 Integrin αvβ6–Targeted SPECT Imaging for Pancreatic Cancer Detection JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 989 OP 994 DO 10.2967/jnumed.113.132969 VO 55 IS 6 A1 Zhaofei Liu A1 Hao Liu A1 Teng Ma A1 Xianlei Sun A1 Jiyun Shi A1 Bing Jia A1 Yi Sun A1 Jun Zhan A1 Hongquan Zhang A1 Zhaohui Zhu A1 Fan Wang YR 2014 UL http://jnm.snmjournals.org/content/55/6/989.abstract AB Integrin αvβ6, a member of the integrin family, is specifically expressed in many malignancies but not in normal organs. Overexpression of integrin αvβ6 is usually correlated with malignant potential and poor prognosis. In this study, we describe the synthesis and evaluation of a 99mTc-labeled integrin αvβ6–targeting peptide as a SPECT radiotracer for the in vivo imaging of integrin αvβ6 expression. Methods: An integrin αvβ6–targeting peptide (denoted as the HK peptide) was conjugated with 6-hydrazinonicotinyl (HYNIC) and radiolabeled with 99mTc using tricine and TPPTS (trisodium triphenylphosphine-3,3′,3″-trisulfonate) as coligands. The in vitro and in vivo characteristics of 99mTc-HYNIC(tricine)(TPPTS)-HK (99mTc-HHK) were investigated in BxPC-3 (integrin αvβ6–positive) and HEK293 (integrin αvβ6–negative) models. The ability of 99mTc-HHK to detect liver metastasis of pancreatic cancer was evaluated using small-animal SPECT/CT. Results: 99mTc-HHK showed high integrin αvβ6–binding specificity both in vitro and in vivo. 99mTc-HHK was cleared rapidly from the blood and normal organs except for the kidneys. The highest uptake (0.88 ± 0.12 percentage injected dose per gram) of 99mTc-HHK in BxPC-3 tumors was observed at 0.5 h after injection. High-contrast images of integrin αvβ6–positive tumors were obtained using 99mTc-HHK. The minimum nonspecific activity accumulation in normal liver tissues rendered high-quality SPECT/CT images of metastatic lesions. Conclusion: 99mTc-HHK is a promising SPECT radiotracer for the noninvasive imaging of integrin αvβ6 expression in vivo. SPECT/CT with 99mTc-HHK could provide an effective approach for the noninvasive detection of primary and metastatic lesions of integrin αvβ6–positive tumors.