Repeat gamma knife radiosurgery for recurrent trigeminal neuralgia

Acta Neurochirurgica (2026) 168:143

This systematic review and meta-analysis evaluates outcomes after repeat Gamma Knife radiosurgery (GKRS) for recurrent trigeminal neuralgia, pooling data from 21 studies comprising 2,020 retreatments. It quantifies efficacy (BNI I–III favourable pain control ~77% after retreatment, 62% at long-term follow-up) and recurrence (~29%), and reports complication rates, notably facial hypoesthesia (~39%).

The paper follows PRISMA and Cochrane guidance, performs single-arm GLMM meta-analyses, sensitivity checks, and meta-regressions that found no consistent predictors of outcome. Limitations include retrospective series, moderate–severe bias, substantial heterogeneity, and variable dosimetry and reporting; prospective standardized studies are recommended.

Clinical context Trigeminal neuralgia causes intense, episodic, shock-like facial pain; Gamma Knife radiosurgery (GKRS) is used for medically refractory cases, and recurrence after initial GKRS can prompt consideration of repeat GKRS.

Study design Systematic review and meta-analysis conducted under PRISMA guidance; included English-language studies of patients needing repeat GKRS after inadequate response to medications and/or a single GKRS, with ≥12 months follow-up.

Evidence base 21 studies were included, comprising 2,486 initially treated patients and 2,020 undergoing repeat GKRS; most were female, median ages ranged 54.5–79.6 years, and ~85% were idiopathic trigeminal neuralgia.

Treatment patterns Most repeat procedures targeted the trigeminal root entry zone (REZ), typically using 70–80 Gy marginal doses; intervals between procedures varied widely (5–138 months; median ≈36 months).

Effectiveness Pain relief after repeat GKRS commonly occurred in ~70–90% of patients with typical improvement in BNI pain scores (often IV–V to I–IIIb); pooled favourable pain control (BNI I–III) after the latest treatment was 76.68%.

Durability & recurrence Median follow-up ranged 14–74 months; recurrence after repeat GKRS was reported around 10–35% (pooled recurrence 29.07%), and favourable pain control at last follow-up decreased to 61.94%.

Safety profile Facial sensory disturbances were frequent (reported 20–45%; pooled facial hypoesthesia 39.04%); bothersome dysesthesias and anesthesia dolorosa were uncommon (<3%).

Predictors/heterogeneity Meta-regression found no significant association between pain relief and age, pain duration, interval since prior GKRS, or dose, with substantial inter-study heterogeneity persisting.