Imaging and biodistribution of Her2/neu expression in non-small cell lung cancer xenografts with Cu-labeled trastuzumab PET

Paudyal, P.*; Paudyal, B.*; Hanaoka, Hirofumi*; Oriuchi, Noboru*; Iida, Yasuhiko*; Yoshioka, Hiroki*; Tominaga, Hideyuki*; Watanabe, Satoshi; Watanabe, Shigeki; Ishioka, Noriko; Endo, Keigo*

Non-small cell lung carcinomas (NSCLC) overexpress the Her2/neu gene in approximately 59% of cases. Trastuzumab, a humanized monoclonal antibody, interferes with Her2 signaling and is approved for the treatment of Her2/neu overexpressing breast cancer. However, its therapeutic use in Her2/neu overexpressing NSCLC remains obscure. The present study aimed to determine the role of Cu-labeled trastuzumab positron emission tomography (PET) for non-invasive imaging of Her2/neu expression in NSCLC. Imaging of Her2/neu expression was performed in NCI-H2170 tumor-bearing mice with Cu-DOTA-trastuzumab. PET studies revealed a significantly high accumulation of Cu-DOTA-trastuzumab in the Her2/neu overexpressing NCI-H2170 tumor at 24 h and 48 h post-injection. Cu-DOTA-trastuzumab showed a very clear image of a Her2/neu positive tumor and appeared to be effective as a PET tracer for imaging of Her2/neu gene expression in NSCLC, suggesting its potential clinical use for identifying patients that might benefit from trastuzumab-based therapy.