Clinical Trial Comparing Dose-intensified SBRT With Conventional Radiation Therapy for Spinal Metastases

Inclusion Criteria: * Established histological diagnosis of a malignant primary or metastatic tumor; * Histologically, radiologically or scintigraphically proven spinal metastasis; * Pain in the affected spinal region or free of pain under pain medication; * Age ≥18 years old; * Karnofsky performance status ≥60%; * Written informed consent. Exclusion Criteria: * Modified Bauer Score \< 2; * No-mass-type metastatic lesion, defined as a 3D space-occupying lesion visible on CT and/or MR; * "Radiosensitive" histology of the primary tumor, e.g., lymphoma, small-cell lung cancer, multiple myeloma, germ cell tumors; * Progressive neurological symptoms/deficit; * More than 3 affected vertebrae in one target site; * More than 2 treatment sites; * Spinal Instability Neoplastic Score (SINS) 13 - 18, i.e., unstable; * Unable to tolerate treatment (unable to lie flat and immobilized); * Previous radiotherapy of the region at the level of the affected vertebrae; * Previous radionuclide therapy within 30 days before stereotactic body radiation therapy; * Previous surgery (stabilization) of the affected vertebrae; * Contraindications for MR scanning, e.g., pacemakers; * Patients with allergy to contrast agents used in computer tomography (CT) and magnetic resonance (MR) imaging or patients who cannot be premedicated to use contrast agent; * Pregnant or lactating women; * Women of child bearing potential or sexually active males not willing to use effective contraception while on treatment and 3 months after the end of treatment; * Mental conditions rendering the patient unable to understand the nature, scope, and possible consequences of the study; * Patient unlikely to comply with protocol, i.e. uncooperative attitude, inability to return for follow-up visits, and unlikely to complete the study.