RecruitingPhase 2Biological interventionA Phase II Study on Adjuvant Vaccination with Dendritic Cells Loaded with Autologous Tumor Homogenate in Resected Stage IV Rare Cancers.Single-arm, monocentric trial to assess safety and immunological efficacy of adjuvant vaccination with autologous dendritic cells loaded with autologous tumour homogenate after curative resection for stage IV rare cancers (In Head/Neck tumors (H\&N), NEuroendocrine Tumors (NET) and Soft Tissue Sarcomas (STS).