Time of Flight Secondary Ion Mass Spectrometry imaging for precise localization of zirconium-labelled trastuzumab in xenograft cancer tumour tissues

The human epidermal growth factor receptor 2 (HER2) specific radiotracer zirconium-Desferrioxamine(DFO)-trastuzumab was visualized ex-vivo by Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) imaging in ovarian and breast cancer xenograft tumor sections. Heterogeneous spatial distribution of [90Zr+] ions reflected the heterogeneous localization of trastuzumab, observed in parallel by immunohistochemistry staining in HER2+ tumors. Our results show that ToF-SIMS imaging is a quick and sensitive technique to image zirconium labelled biologics at microscale in tissues.