To report the level of effectiveness and safety, in our experience, of CyberKnife (Accuray, Inc., Sunnyvale, CA) robotic radiosurgery as a first-line treatment against pharmacologically refractory trigeminal neuralgia.
We treated 33 patients with the frameless CyberKnife system as a monotherapy. The retrogasserian portion of the trigeminal nerve (a length of 4 mm, 2-3 mm anterior to the root entry zone) was targeted. Doses of 55 to 75 Gy were prescribed to the 100% isodose line, according to a dose escalation protocol. The patients were evaluated for the level of pain control, time to pain relief, hypesthesia, and time to pain recurrence.
The median age was 74 years. All but 2 patients (94%) achieved a successful treatment outcome. The follow-up period was 9 to 37 months (mean, 23 months). The Barrow Neurological Institute Pain Intensity Scale (BPS) score before radiosurgery was III in 2 patients (6%), IV in 8 patients (24%), and V in 23 patients (70%). The time to pain relief was 1 to 180 days (median, 30 days). No facial numbness was observed. Only 1 patient developed a transitory dysesthesia of the tongue. After treatment, the BPS score was I, II, or III in 31 patients (97%). Pain recurred in 33% (11 patients) at a mean of 9 months (range, 1-43 months). Three patients with recurrences had low pain control by medication (BPS score, IV), and 1 patient (BPS score, V) needed a radiofrequency lesioning (BPS score, I at 12 months).
CyberKnife radiosurgery for trigeminal neuralgia allows pain relief at safe doses and is suggested for pharmacologically refractory trigeminal neuralgia. Higher prescribed doses were not associated with improvement in pain relief or recurrence rate.
Intracranial neoplasms can cause pain similar to trigeminal neuralgia. Literature regarding radiosurgery for this is limited. We present a retrospective review of patients with tumor-related facial pain from benign lesions treated with gamma knife radiosurgery (GKRS) at Wake Forest University.
The primary objectives were to determine long-term pain relief and predictive factors for pain alleviation.
We reviewed 515 patients treated with GKRS for benign meningioma, vestibular schwannoma or trigeminal schwannoma between August 1999 and August 2010. Twenty-one eligible patients had tumor-related facial pain prior to GKRS. The median marginal tumor dose was 12 Gy. Long-term pain relief data were obtained by chart review and telephone interview.
The median follow-up for symptom evaluation was 3.8 years. Seventeen of 21 patients (81%) experienced a Barrow Neurological Institute (BNI) score of I-III at 6 months following GKRS. Kaplan-Meier estimates of freedom from BNI IV-V relapse were 66% at 1 year and 53% at 2 years. No pain relapses occurred after 2 years.
GKRS of benign lesions is a noninvasive option for patients with tumor-related facial pain. Pain relief is modest, with the majority of pain relapses occurring within 2 years and approximately one half of patients maintaining relief beyond 2 years.
To determine factors associated with the durability of stereotactic radiation surgery (SRS) for treatment of trigeminal neuralgia (TN).
Between 1999 and 2008, 446 of 777 patients with TN underwent SRS and had evaluable follow-up in our electronic medical records and phone interview records. The median follow-up was 21.2 months. The Barrow Neurologic Institute (BNI) pain scale was used to determine pre- and post-SRS pain. Dose-volume anatomical measurements, Burchiel pain subtype, pain quality, prior procedures, and medication usage were included in this retrospective cohort to identify factors impacting the time to BNI 4-5 pain relapse by using Cox proportional hazard regression. An internet-based nomogram was constructed based on predictive factors of durable relief pre- and posttreatment at 6-month intervals.
Rates of freedom from BNI 4-5 failure at 1, 3, and 5 years were 84.5%, 70.4%, and 46.9%, respectively. Pain relief was BNI 1-3 at 1, 3, and 5 years in 86.1%, 74.3%, and 51.3% of type 1 patients; 79.3%, 46.2%, and 29.3% of type 2 patients; and 62.7%, 50.2%, and 25% of atypical facial pain patients. BNI type 1 pain score was achieved at 1, 3, and 5 years in 62.9%, 43.5%, and 22.0% of patients with type 1 pain and in 47.5%, 25.2%, and 9.2% of type 2 patients, respectively. Only 13% of patients with atypical facial pain achieved BNI 1 response; 42% of patients developed post-Gamma Knife radiation surgery (GKRS) trigeminal dysfunction. Multivariate analysis revealed that post-SRS numbness (hazard ratio [HR], 0.47; P