PT - JOURNAL ARTICLE AU - Zhang, Jinming AU - Zhang, Xiaojun AU - Tian, Jiahe TI - <strong>Synthesis &amp; biological evaluation of <sup>99m</sup>Tc-AMD3465 as a SPECT tracer for CXCR4 receptor imaging.</strong> DP - 2018 May 01 TA - Journal of Nuclear Medicine PG - 1119--1119 VI - 59 IP - supplement 1 4099 - http://jnm.snmjournals.org/content/59/supplement_1/1119.short 4100 - http://jnm.snmjournals.org/content/59/supplement_1/1119.full SO - J Nucl Med2018 May 01; 59 AB - 1119Objectives: Purpose A number of attempts have been made to non-invasively image CXCR4 receptor, such as 64Cu-AMD3100 &amp; 68Ga-Pentixafor. AMD3465 was successfully labeled with 64Cu &amp; evaluated for imaging CXCR4 expression in a tumor. We tried to use the monocyclam to form strong complexes with 99mTc to develop 99mTc-AMD3465 as an imaging agent for SPECT. Methods AMD 3465 was synthesized by a four-step reaction from the cyclam. 99mTc-AMD3465 was labeled with 99mTcO4- by reduction with stannous chloride. The homologous binding assay was performed in Jurkat-T cells. Biodistribution &amp; SPECT images were obtained in mice bearing H460 tumor. Results The radiochemical purities (RCP) of 99mTc-AMD3465 were over 99 %. Heterologous binding assays showed IC50 values of 72.2±1.4μM for 99mTc-AMD3465. The partition co-efficient (log P) value of 99mTc-AMD3465 was -2.67, suggesting this radiotracer was hydrophilic. The value was the same as that of 64Cu-AMD3465, which was -2.67. The accumulation of 99mTc-AMD3465 was higher in the liver, spleen &amp; bone, which is consistent with the known high expression of CXCR4 in these organs. The H460 tumor was seen clearly after injection of 99mTc-AMD3465 . The T/NT was 2.6±1.2 at 60 min. Conclusion 99mTc-AMD3465 showed specific binding to organs with high CXCR4 expression, &amp; could be used to image CXCR4 receptors.