ERBB2 and breast cancer: Moreover, the use of HER2-targeted PET imaging, using 64Cu-tetra-azacyclododecanetetra-acetic acid (DOTA)-Trastuzumab, has been attempted [5, 6, 11, 13, 14]; related clinical trials in the USA and Japan showed effective identification of HER2 expression in breast cancer patients [5, 6, 13, 14].