Inclusion Criteria:  Retrospective study A Baseline WBMRI scans in metastatic APC patients acquired up to 8 weeks prior to the initiation of a new line of therapy.  Retrospective study B Paired WBMRI scans in metastatic APC patients at baseline within 8 weeks prior to treatment and at 12 ± 3 weeks after systemic treatment  Prospective study C Written informed consent. Age ≥18 years. Advanced prostate cancer patients with indication for systemic anti-cancer therapy to be enrolled in a clinical study.  Participants must have a baseline WBMRI and CT-guided bone marrow biopsy.  Exclusion Criteria:  Prospective Study C Patient is claustrophobic. Contraindications to MRI examination (e.g., cardiac pacemakers, cochlear implants).