Treatment of Recurrent or Progressive Meningiomas With the Radiolabelled Somatostatin Antagonist 177Lu-satoreotide

Inclusion Criteria: * Informed Consent as documented by signature * Participants of any gender and of age \> 18 years * Female participants capable of giving birth (who are not surgically sterilized or are less than 2 years in their menopause) must use a medically accepted contraceptive and must agree to use it during and till 3 months after the treatment. As acceptable contraceptive count sexual abstinence or double contraceptive methods: hormonal contraceptive (oral, transdermal, implants or injections) in combination with barrier methods (spiral, condom, diaphragm) * Male participants must use medically accepted contraceptive during and till 3 months after treatment * The participants' Karnofsky Performance Status must be ≥ 60 * The participants must be patients with a histologically or clinically confirmed (MRI + somatostatin receptor imaging) recurrent or progressive meningioma * There must be no other standard therapeutic alternatives for the participants * The participants tumour must be measurable according to RECIST v1.1 with a minimal diameter of 1.0 cm. * The participants must have a confirmed expression of somatostatin receptor (SSTR) on 68Ga- DOTATOC positron emission computed tomography (PET)/CT scan * Blood parameter criteria are: h) Leucocytes ≥ 3\*109/L i) Haemoglobin ≥ 80 g/L j) Thrombocytes ≥ 90\*109/L k) Estimated glomerular filtration rate ≥ 50 ml/min l) Albumin \> 25g/L m) alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AP): ≤ 5 times upper standard value n) Bilirubin ≤ 2 times upper standard value Exclusion Criteria: * Known intolerance against 177Lu, DOTA, JR11, TOC or against one of the components of 177Lu-DOTA-JR11 or 177Lu-DOTATOC * Ongoing infection at the screening visit or a serious infection in the past 4 weeks * Administration of another investigational product in the last 60 days before Visit 1 Day 1 * Prior or planed administration of a therapeutic radio-pharmaceutical during 8 half-lives of the used radio-pharmaceutical's radionuclide, also during the ongoing study * Any extensive Radiotherapy involving bone marrow over the last 3 months before inclusion to the study * Chemotherapy in the last 2 months before inclusion * Pregnant or breastfeeding female patients. A pregnancy test will be performed in all women of child bearing potential. * Any uncontrolled significant medical, psychiatric or surgical condition (active infection, unstable angina pectoris, cardiac arrhythmia, poorly controlled hypertension, poorly controlled diabetes mellitus \[HbA1c ≥ 9%\], uncontrolled congestive heart disease, etc.) or laboratory findings that might jeopardize the patient's safety or that would limit compliance with the objectives and assessments of the study. Any mental conditions which prevent the patient from understanding the type, extent and possible consequences of the study and/or an uncooperative attitude from the patient.