Fig. 3

a ⁸⁹Zr-Trastuzumab-PET/CT in a patient with HER2-negative primary breast cancer showing intense tracer uptake in a right supraclavicular lymph node metastasis. b Immunohistochemistry of the primary cancer proved HER2-negativity, while c biopsy and immunohistochemistry of the suspicious lymph node showed markedly HER2-positive metastatic disease. This patient responded to HER2-directed therapy. Adapted and reprinted with permission from Ulaner et al. J Nucl Med 2016;57:1523–1528