ERBB2 and head and neck squamous cell carcinoma: Moreover, 89Zr demonstrated ideal characteristics for optimal image quality and accurate quantification such as the first clinical study involving PET with 89Zr-labeled-chimeric mAb, U36, in patients with head and neck squamous cell carcinoma (HNSCC) [44] and the 89Zr -trastuzumab PET guided visualization and quantification of HER2-positive lesions in patients with HER-2 positive metastatic breast cancer [19].