Rationale: PSMA is a transmembrane protein, which is expressed on prostate cancers cells, ACC and other malignancies. In prostate cancer, distant metastases can be visualized sensitively and non-invasively with 68Ga-PSMA-PET/CT scans and if the uptake of 68Ga is high enough, patients can be treated with the β-emitting radionuclide 177Lu-PSMA. In the current study, we will evaluate the uptake of 68Ga-PSMA by performing 68Ga-PSMA-PET/CT scans in advanced ACC and SDC patients. If the uptake is high enough, this will form the rationale for a therapeutic study with 177Lu-PSMA in ACC and SDC.