Intervention description {11a}
radioresistant tumors
SPINAL METASTASES
Patients who accept the intervention will receive same-day SBRT and surgery. Before treatment, patients will undergo an extended MRI and CT scan in treatment position for planning purposes. Next, cone beam CT (CBCT) before and during dose delivery is made to correct for position deviations. Then, patients will receive SBRT, which will be a single high dose of at least 18 Gray (Gy); this dose can be increased to 21 Gy in patients with radioresistant tumors, to the affected vertebra. Dose constraints are set for the organ at risks based on institution specific guidelines. Within 24 h after SBRT, surgical stabilization with or without decompression will be performed according to the standard of care and on an elective base. The type of (pedicle screw) fixation will be decided by the surgeon depending on the need for surgical decompression, vertebral levels to be included in the construct, and the bone quality.The control arm and patients who refused to undergo the intervention will receive the standard of care. Currently, the standard of care for patients with unstable spinal metastases is surgical stabilization with or without decompression followed by cRT or SBRT as soon as the surgical wound has healed sufficiently. Before surgery, all patients will undergo an extended planning MRI in radiotherapy treatment position. After surgery and before radiotherapy, when the wound is healed sufficiently, a planning CT is made and another MRI to see if the neurological structures have moved after surgery. Pre- and postoperative MRI are mutually registered to yield information on all relevant structures for planning assessing dose distribution using volumetric modulated arc therapy (VMAT). Also, CBCT data will be acquired to correct for translations or rotations, and if correct in subsequent CBCTs, radiotherapy will be delivered.