Objectives: Primary: to develop a model based on demographic, clinical and radiological parameters for prediction of treatment success after TEI Secondary: to estimate the short-term efficacy of TEI in patients with LDH and spinal stenosis based on pain, functionality and perceived recovery scores, to determine the correlation between clinical and radiological baseline parameters and physical and psychological patient outcome measures, to determine the rate of additional injections and rate of surgery after treatment with TEI, to determine the short-term (cost)effectiveness of TEI on physical and psychological patient outcome measures, and to determine the rate of complications associated with TEI Study design: Prospective cohort study Study population: Patients that are scheduled for TEI as part of usual care suffering from a new episode of lumbar radiculopathy Main study parameters/endpoints: leg and back pain scores at baseline, 30 minutes, 2 and 6 weeks after treatment. ODI, HADS, Quality of Life and PCI at baseline, 2 and 6 weeks after treatment. Perceived recovery at 2 and 6 weeks after treatment. Usage of healthcare at baseline, 2 and 6 weeks after treatment.