Review Question - QID 3699

A 65-year-old female with a history of breast cancer presents with bilateral buttock and leg pain that is worse with walking and improves with sitting. In addition, she reports that she feels unsteady on her feet and requires holding the railing when going up and down stairs. On physical exam she is unable to complete a tandem gait and has hip flexion weakness, ankle dorsiflexion weakness, and ankle plantar flexion weakness. Her reflex exam shows 3+ bilateral patellar reflexes. Radiographs and an MRI are shown in Figure A and B. What is the next most appropriate step in management.