Lutetium-177-PSMA Radioligand Therapy in Advanced Salivary Gland Cancer Patients

Inclusion Criteria: * Patients must have the ability to provide written informed consent. * Patients must be ≥ 18 years of age. * Patients must have an ECOG performance status of 0 to 2. * Patients must have histological, pathological, and/or cytological confirmation of either adenoid cystic carcinoma or salivary duct carcinoma. * Patients must have incurable, local or regional recurrent or metastatic ACC or SDC. * Patients with ACC can only participate in case of objective growth in the last three months or complaints due to the disease. * Patients must have adequate organ function: * Sufficient bone marrow capacity as defined by: WBC count (white blood cell) ≥2.5x10\^9/L, PLT (platelet) count ≥100x10\^9/L, Hb ≥6 mmol/L, absolute neutrophil count (ANC) ≥1.5x10\^9/L * Adequate liver function as defined by:Total bilirubin ≤1.5 x ULN. For patients known with Gilbert's Syndrome ≤ 3 x ULN is permitted. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤3.0 × ULN OR ≤5.0 × ULN for patients with liver metastases. * Adequate kidney function as defined by:serum creatinine ≤1.5 x ULN or creatinine clearance ≥ 50 mL/min * Patients must have measurable disease at baseline. Defined as ≥ 1 lesion ≥ 2 cm (long axis) that is present on baseline CT. * Patients must have a positive 68Ga-PSMA PET/CT scan, defined by at least one lesion ≥ 1.5 cm (long axis) with a ligand uptake above liver level. Exclusion Criteria: * Patients whom are pregnant or breast feeding. * P…