Gamma Knife Radiosurgery, Central Lateral Thalamotomy, and Chronic Neuropathic Pain: A Prospective Single-Center Study With Long-Term Follow-Up.

Abstract

Objective: We present our experience in using Gamma knife surgery (GKS) on the posterior part of the central lateral nucleus (CLp) for refractory neuropathic pain, examining its long-term efficacy and safety in patients with one of the longest pretreatment pain duration in the literature. Furthermore, we examined certain factors that might influence the outcome of this technique.

Methods: We conducted a prospective study involving 9 patients who underwent GKS between 2020 and 2023. We employed Icon model GKS and Vantage stereotactic frame. The planning process encompassed a dual localization system. The assessments involved the use of both the visual analog and Barrow Neurological Institute (BNI) scales (6 months, 12 months, and then annually). Data analysis was developed using SPSS 25.

Results: Our series consisted of 6 women and 3 men with an average age of 52.3 ± 17.4 years. A maximum dose of 130 Gy was administered. The mid-term postoperative period (1 year) showed that 8 patients (88.9%) experienced significant pain relief (visual analog scale P = 0.011; BNI IIIa). The median follow-up time was 24.8 ± 8.2. At the last assessment, all patients maintained their improvement (visual analog scale P = 0.018; BNI IIIa). We found no association between patient age (P = 0.329), duration of pretreatment pain (P = 0.469), multiple previous surgical treatments (P = 0.750) or the pain's etiology (P = 0.25), and poorer outcomes post CLp thalamotomy. None of the cases has experienced a recurrence so far. Both morbidity and mortality were 0%.

Conclusions: Our findings suggest that bilateral ablation of the CLp using GKS is both effective and safe for treating drug-resistant neuropathic pain. This simple, accurate, and noninvasive surgical technique effectively achieves pain control across various localized areas and sustains a lasting clinical response, even in patients with multiple previous surgical interventions or prolonged pain duration.