In 2010, a first PET imaging study for CNS tumor targeting was performed using the mAb trastuzumab labeled with zirconium-89, [89Zr]Zr-trastuzumab, in patients with brain metastases from human epidermal growth factor receptor 2 (HER2)-positive breast cancer [133]. Here, ERBB2 is linked to central nervous system neoplasm.