Effectiveness of High-Voltage PRF for Chronic Lumbosacral Radicular Pain

Effectiveness of High-Voltage Pulsed Radiofrequency for Chronic Lumbosacral Radicular Pain: A Randomized Controlled Trial

This randomized controlled trial compared high-voltage (60 V) and low-voltage (45 V) pulsed radiofrequency (PRF) for treating chronic lumbosacral radicular pain in adult patients. The study evaluated differences in pain reduction (using the Visual Analogue Scale [VAS] and Numeric Rating Scale [NRS-11]), functional ability (using Oswestry Disability Index scores), serum Interleukin-6 levels, and overall safety. All participants received fluoroscopy-guided PRF at 42°C for three 120-second cycles and were followed for approximately 6 weeks.

Consecutive patients who met the inclusion and exclusion criteria were enrolled and randomized into two groups: the intervention group (high-voltage PRF, 60 V) and the control group (low-voltage PRF, 45 V). The sample size was calculated using the Neyman-Pearson approach with a superiority hypothesis, assuming that the intervention group would achieve greater pain reduction than the control group. Accounting for an estimated 20% dropout rate, 11 participants were required per group. Patients who voluntarily withdrew from the study were excluded from analysis, whereas patients who discontinued the intervention due to adverse effects during or after the procedure were included in the analysis and reported.

Inclusion Criteria:

• Adults aged ≥ 18 years old
• Numeric Rating Scale (NRS-11) ≥ 4 at screening
• Clinical diagnosis of lumbosacral radicular pain with symptom duration ≥ 12 weeks
• Insufficient response to conservative therapy, including but not limited to pharmacotherapy and/or physiotherapy

Exclusion Criteria:

• Known hypersensitivity or allergy to medication required during the study (e.g., steroid, contrast media)
• Coagulopathy, systemic infection, localized infection at needle-entry site, lumbar fracture, myelopathy, or severe organ dysfunction (e.g., renal failure, heart failure, severe respiratory diseases)
• Comorbidities that compromise valid pain assessment (e.g., post-stroke, central neuropathy, malignancy)
• Previous neurological deficits
• Pregnancy
• Refusal of participation in the study