Pulsed radiofrequency of S2–4 nerve roots vs ganglion impar neurolysis for severe perineal cancer pain

Introduction: Perianal and perineal-related cancer pain is deemed severe in most patients with cancer, and its management poses a significant challenge due to rich innervation of this region. Objectives: This study compared the analgesic efficacy of bilateral selective pulsed radiofrequency (PRF) of sacral nerve roots (S2–S4) with ganglion impar neurolysis (GIN) in patients experiencing severe perianal and perineal cancer pain. Methods: Forty patients with severe perineal or perianal cancer pain, defined by a visual analogue scale (VAS) score ≥7, were randomized to 1 of 2 groups. Both procedures were performed under fluoroscopic guidance: the PRF group received bilateral selective PRF of sacral nerve roots (S2–S4), whereas the GIN group underwent ganglion impar neurolysis using a 6% phenol in saline injection. The primary outcome was the VAS score at 4 weeks. Results: Both groups showed significant reductions in VAS scores up to 12 weeks post-treatment compared to baseline ( P < 0.001). The PRF group had significantly lower VAS scores than the GIN group at postanesthesia care unit, and at 1, 4, and 8 weeks ( P < 0.05). Oxycodone and pregabalin consumption were lower in the PRF group at these intervals. The PRF group experienced a longer procedure duration and a higher incidence of injection site pain ( P < 0.05). However, quality-of-life scores and patient satisfaction were significantly higher in the PRF group. Conclusion: Bilateral PRF of sacral nerve roots (S2–S4) resulted in more analgesic efficacy and improved quality-of-life compared to GIN in patients with severe perineal and perianal cancer pain, despite higher rate of injection site discomfort.