Inhibitors of the programmed cell death protein 1 (PD-1)/PD-L1 immune checkpoint signaling pathway are already approved in the treatment of various tumor entities in relapsed or metastatic stages. Different exploratory trials suggest that the combination of radiotherapy and PD-1/PD-L1 inhibitors is highly effective, especially in oligometastatic stages and if all lesions are treated with ablative radiotherapy. In addition, the role of predictive biomarkers is becoming increasingly important for future therapy algorithms. First data, also from our group, indicate clearly that dynamic changes of immune cells and their activation markers in the peripheral blood (immune matrix) can be used as predictive biomarkers. During the planned STICI-02 trial predictive immune matrix derived from the STICI01 trial (NCT03453892) will be validated in the groups of patient suffering from HNSCC (palliative), NSCLC (separately palliative and adjuvant) and other solid tumors (including in particular esophageal carcinomas, urothelial and renal carcinomas, small cell bronchial carcinomas and squamous cell carcinomas of the skin \[depending on the current drug approval\]). Within the framework of scientific accompanying projects, the predictive value of markers in tumor tissue and of pattern radiomics analyses will be analyzed accompanying the immunophenotyping in peripheral blood. The side effects