Fig. 1: Study design for patients with combined ICI.

PET/CT and sequencing of tumour normal pairs for patients under palliative ICI were done before treatment start. Blood samples were taken at T0, T1 (3 weeks) and T2 (second PET/CT, 12 weeks). Additional blood samples were collected during therapy and follow-up to increase the sensitivity for changes in allele fractions during and after therapy completion.