Stereotactic radiosurgery for primary trigeminal neuralgia: state of the evidence and recommendations for future reports.

OBJECTIVE: To identify systematically all the studies reporting outcomes and complications of stereotactic radiosurgery for trigeminal neuralgia and to evaluate them against predefined quality criteria.
METHODS: Inclusion criteria for outcome analysis included thorough demographic documentation, defined diagnostic and outcome criteria, a minimum of 30 patients treated with 12 months median/mean follow up, not more than 20% lost to follow up, Kaplan-Meier actuarial analysis, primary trigeminal neuralgia, not more than 10% of patients retreated for failure or early recurrence, and minimum dose of 70 Gy.
RESULTS: Of 38 studies identified, four could be used to evaluate rates of pain relief on a yearly basis, and two for actuarial rates of complete pain relief; seven provided data on latencies and 18 were used to evaluate complications. Pain relief typically occurs within three months. Complete relief is initially achieved by three quarters of the patients, but half maintain this outcome at three years. One half or less can permanently stop drug treatments. Sensory disturbance, including anaesthesia dolorosa, is the most frequent complication of stereotactic radiosurgery.
CONCLUSIONS: Outcomes after stereotactic radiosurgery appear in line with other ablative techniques. Results are better when it is used as primary treatment in patients with typical symptoms. Current data are largely observational and the quality is generally poor. This technique should be evaluated in a randomised, controlled trial with universal outcome measures, actuarial methodology, and validated measures of patient satisfaction and quality of life.