Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

BACKGROUND: Trigeminal neuralgia (TN) may recur after treatment by gamma knife stereotactic radiosurgery (GKSR). OBJECTIVE: To evaluate management outcomes in patients who underwent repeat GKSR for TN. METHODS: The authors reviewed their experience with repeat GKSR in 119 patients with recurrent TN. The median patient age was 74 years (range, 34-96 years). The median interval between procedures was 26 months. The median target dose for repeat GKSR was 70 Gy (range, 50-90 Gy) and the median cumulative dose was 145 Gy (range, 120-170 Gy). The median follow-up was 48 months (range, 6-187 months) after repeat GKSR. RESULTS: After repeat GKSR, 87% of patients achieved initial pain relief (Barrow Neurological Institute pain score I-IIIb). Pain relief was maintained in 87.8% at 1 year, 69.8% at 3 years, and 44.2% at 5 years. Facial sensory dysfunction occurred in 21% of patients within 18 months after GKSR. Longer pain relief was observed in patients who had recurrent pain in a reduced pain distribution of the face compared with the pain distribution at the time of their initial GKSR, and in those who developed additional trigeminal sensory loss after a repeat procedure. A cumulative edge of brainstem dose >= 44 Gy was more likely to be associated with the development of sensory loss. CONCLUSION: Repeat GKSR provides a similar rate of pain relief as the first procedure. The best responses were observed in patients who had good pain control after the first procedure and those who developed new sensory dysfunction in the affected trigeminal distribution.