Fig. 1.

Upper image: three PET scans ([¹⁸F]-FDG-PET, [¹⁸F]-FES-PET, and [⁸⁹Zr]-trastuzumab-PET) in the same patient showing mediastinal and hilar lymph node metastases, as well as intrapulmonary lesions visible on both [¹⁸F]-FDG-PET and [¹⁸F]-FES-PET, but not on [⁸⁹Zr]-trastuzumab-PET. The large mediastinal mass (first row of transversal fused images) was visible on all three imaging modalities. Bone metastases (second row of transversal fused images) were clearly visualized on [¹⁸F]-FES-PET, for example, skull lesions, and to a lesser extent on [¹⁸F]-FDG-PET and [⁸⁹Zr]-trastuzumab-PET. Lower image: [¹⁸F]-NaF-PET in another patient showing bone metastases in the skull, vertebrae, costae, pelvis, and proximal femora. The increased uptake in the joint was related to degeneration