HIghly MetAstatic Life Prolonging Therapy-Resistant Prostate Cancer: Role of Stereotactic Radiotherapy for Bone and Lymph Node Metastases (HIMARS)

Inclusion Criteria: * Metastatic prostate cancer with clinical progression after the use of androgen-receptor pathway inhibitor, chemotherapy or any other life-prolonging therapy. Patient could have been treated previously by RadioLigand Therapy (RLT). * Performance Status \< 3 * Bone and/or lymph node metastases based on conventional (CT and bone scan) or metabolic imaging * Bone and/or lymph node metastases suitable for SRT, according to the investigator * Adequate organ function: 1. Absolute Neutrophil Count (ANC) ≥ 1000/mm3 or 2. Platelet Count ≥ 50 000/mm3 or 3. Haemoglobin ≥ 8 g/dL (allowing transfusion or other intervention to achieve this minimum haemoglobin) * Age ≥ 18 years at time of study entry * Written informed consent obtained from the patient prior to performing any protocol-related * Patient is willing and able to comply with the protocol for the duration of the study including undergoing treatment and scheduled visits and examinations including follow up. * Patient has valid health insurance * Life time expected \> 3 months Exclusion Criteria: * Evidence of symptomatic metastases to the lungs, brain, peritoneum or liver * Evidence of diffuse metastatic spread to the bone marrow (e.g. positive super bone scan) or the cerebral spinal fluid as per bone scan (no lumbar puncture required). * Evidence of presence of symptomatic spinal cord compression with indication of neurosurgical decompression. * Patient with symptomatic and/or high-risk tumor volume-to-bone marrow reserve ratio \> 50% * Concurrent enrolment in another clinical study, unless it is a non-therapeutic clinical study * Mental impairment (psychiatric illness/social situations) that may compromise the ability of the patient to give informed consent and comply with the requirements of the study; * Patient who has forfeited his/her freedom by administrative or legal award or who is under guardianship; * Patients unable to undergo medical follow-up in the study for geographical, social or psychological reasons. * History of another primary malignancy except for 1. Malignancy treated with curative intent and with no known active disease ≥2 years before the first dose of SRT and of low potential risk for recurrence 2. Adequately treated non-melanoma skin cancer or lentigo maligna without evidence of disease 3. Adequately treated carcinoma in situ without evidence of disease * Uncontrolled pain that contraindicates patient positioning on the radiotherapy table according to investigator * Patient indicated to or currently treated by cytopenic treatment as chemotherapy or RadioLigand Therapy * Patient under concomitant treatment that may generate severe gastro-intestinal disorder or genito-urinary disorder