SPECT has limitations regarding spatial resolution and sensitivity in deep tissue.18 To optimise HER2 detection further, PET has been used with zirconium‐89 labelled trastuzumab.19, 20, 21 [89Zr]‐Labelled trastuzumab accumulated in HER2‐positive tumours in mice and was further evaluated in humans. This evidence concerns the gene ERBB2 and neoplasm.