Tag: Secondary

Neurosurgery 97:1003–1011, 2025

This clinical study evaluates long-term pain outcomes after Gamma Knife radiosurgery (GKRS) for secondary tumor-related trigeminal neuralgia in 156 patients, reporting complete pain relief (BNI 1) in 38.8% and adequate relief (BNI 2–3) in 47.4% over a median 48.5-month follow-up. The cohort—predominantly schwannomas and meningiomas—received tumor-targeted single-session GKRS with a median dose of 12 Gy and facial hypesthesia noted in 8.3%.

Multivariable analysis identified age ≥50 years and decreased or stable tumor volume at follow-up as strong predictors of favorable pain outcomes, while tumor progression and younger age predicted failure. The authors conclude tumor control contributes to pain relief but is not the sole mechanism, and targeting tumor alone achieved similar BNI 1–3 rates as reports that also targeted the nerve.

• Gamma Knife Radiosurgery (GKRS) Efficacy: GKRS provides complete pain relief (BNI 1) in 38.8% and adequate pain relief (BNI 2-3) in 47.4% of patients with secondary tumor-related trigeminal neuralgia, with a median follow-up of about 48.5 months.

• Predictors of Pain Relief: Age ≥50 years (odds ratio: 6.95) and decreased or stable tumor volume at follow-up (odds ratio: 40.38) significantly predict successful pain relief (BNI 1-3) after GKRS.

• Tumor Control and Pain Relief Relationship: While tumor control (stable or reduced volume) strongly correlates with pain relief, pain relief can still occur without significant tumor shrinkage, indicating other contributing mechanisms.

• Most Common Tumor Types: Schwannomas (67.9%) and meningiomas (29.6%) are the most frequent causes of secondary tumor-related trigeminal neuralgia treated with GKRS.

• Complications: Facial hypesthesia is the most common complication post-GKRS, affecting 8.3% of patients; no cases of anesthesia dolorosa or worsening pain were reported.

• Tumor Volume Impact: Larger pre-treatment tumor volume is associated with higher rates of pain relief failure; patients with pain relief failure had a median tumor volume of 5.9 cc versus 3.1–4 cc in those with successful outcomes.

• Prior Procedures: Previous interventions (such as radiofrequency ablation, rhizotomy, or tumor resection) do not significantly affect pain relief outcomes after GKRS.

• Alternative Approaches: Targeting the tumor alone with GKRS is effective; nerve targeting may be reserved for cases where tumor-targeted GKRS fails.