Pilot Randomized Study for Treatment Volume De-Escalation for Spinal Metastases With Stereotactic Body Radiation Therapy

Inclusion Criteria: * Patients affected by spinal metastases eligible for SBRT * All histologies are allowed * Oligometastatic disease (maximum 5 metastases) in every setting (oligopersistent, oligorecurrent and oligoprogressive, according to ESTRO consensus) * Metastases treated with ablative intent * Both symptomatic and asymptomatic vertebral metastases * Spine Instability Neoplastic Score (SINS) score \< 7 \[18\] * Age \> 18 years * Life expectancy \> 12 months * PS ECOG 0-1 * Vertebral pathological lesion on the diagnostic MRI * Single active lesion on the target vertebra * More lesions in different vertebrae can be simultaneously treated * Informed consent to trial participation and personal data treatment Exclusion Criteria: * More than 2 adjoining vertebrae involved * Palliative intent * 2 or more lesions on the target vertebra * Contraindications to MRI * More than 5 metastases