PD-L1 PET Imaging in Melanoma Patients

This is a single center feasibility study for the application of \[18F\]PD-L1 PET in patients with metastatic melanoma and NSCLC treated with anti-PD-1 therapy. The study will consist of a pharmacokinetics phase (phase one) and tracer validation phase (phase two). Phase one will be performed in a maximum of 5 patients. A \[18F\]PD-L1 PET scan will be performed at baseline and six weeks after treatment initiation. Upon finishing phase one, the optimal time for tracer injection will bedetermined prior to the start of phase two. In phase two a \[18F\]PD-L1 PET-CT scan will be performed in 10 patients at baseline and six weeks after treatment initiation. Also, when it is feasible a biopsy will be taken from at least one accessible tumor location after the PET-scan at baseline and the PET-scan after six weeks of therapy.