Purpose: To assess the safety, efficacy, and quality of life (QOL) associated with radiosurgical treatment for trigeminal neuralgia (TN).
Methods and materials: Between June 1996 and June 2001, 112 patients with TN refractory to medical or surgical management were treated with gamma knife radiosurgery (GKRS) at the University of Maryland Medical Center. A median prescription dose of 75 Gy (range: 70-80 Gy) was delivered to the involved trigeminal nerve root entry zone. Treatment outcomes were assessed through patient self-reports of pain control and medication usage during follow-up visits. In addition, patients responded to a standard questionnaire containing the Barrow Neurologic Institute Pain Scale (BNI) and selected sections of the McGill Pain Scale. Treatment outcomes and objective quality of life measures were also addressed.
Results: Ninety-six patients (86%) completed questionnaires for a median follow-up of 30 months (range: 8-66 months). Seventy-four patients (77%) reported pain relief occurring after a median of 3 weeks (range: 0-24 weeks) after GKRS. A decrease in medication usage was noted in 66% of patients. Actuarial analysis demonstrated 1-year, 2-year, and 3-year recurrence rates of 23%, 33%, and 39%, respectively. Response to treatment was associated with lack of prior surgical treatment (p = 0.03) and less than 50 months' pain duration before GKRS (p = 0.04). Patients who described their TN pain as more severe than their worst non-TN headache pain (McGill Pain Scale IV-V vs. I-III) were also more likely to respond to treatment (p < 0.001). Seven (7.3%) patients reported new or increased trigeminal dysfunction; however, only 3.1% reported these symptoms as bothersome (BNI III-IV). Patients with sustained pain relief reported an average of 100% improvement in their QOL as a direct result of pain relief after GKRS, and 100% believed that the procedure was successful. Furthermore, among those patients with temporary pain relief and subsequent recurrence, 65% felt their treatment was a success with an average of 80% improvement in their QOL.
Conclusions: GKRS provides significant pain relief and improves QOL in the majority of patients treated for TN, with few bothersome side effects. Patients with both temporary and sustained responses to treatment realized significant improvements in QOL after GKRS, and considered their treatment successful. Longer follow-up of these patients may reveal additional recurrences highlighting the importance of studies evaluating repeat GKRS and optimization of current treatment techniques and patient selection.