The results of this study suggest the following optimal radiosurgical treatment parameters for treatment of idiopathic trigeminal neuralgia: a median maximal dose of 78 Gy (range, 70-85.4 Gy) and a median length of the nerve treated of 6 mm (range, 5-12 mm).

Object Gamma knife surgery is an accepted treatment option for trigeminal neuralgia (TN). The safety and efficacy of CyberKnife radiosurgery as a treatment option for TN, however, has not been established. Methods Forty-one patients were treated between May 2002 and September 2004 for idiopathic TN at Stanford University and the Rocky Mountain CyberKnife Center. Patients with atypical pain, multiple sclerosis, or previous radiosurgical treatment or a follow-up duration of less than 6 months were excluded. Patients were evaluated for the level of pain control, response rate, time to pain relief, occurrence of hypesthesia, and time to pain recurrence with respect to the length of the nerve treated and the maximum and the minimum dose to the nerve margin. Thirty-eight patients (92.7%) experienced initial pain relief at a median of 7 days after treatment (range < 24 hours–4 months). Pain control was ranked as excellent in 36 patients (87.8%), moderate in two (4.9%), and three (7.3%) reported no change. Six (15.8%) of the 38 patients with initial relief experienced a recurrence of pain at a median of 6 months (range 2–8 months). Long-term response after a mean follow-up time of 11 months was found in 32 (78%) of 41. Twenty-one patients (51.2%) experienced numbness after treatment. Conclusions CyberKnife radiosurgery for TN has high rates of initial pain control and short latency to pain relief compared with those reported for other radiosurgery systems. The doses used for treatment were safe and effective. Higher prescribed doses were not associated with improvement in pain relief or recurrence rate. The hypesthesia rate was related to the length of the trigeminal nerve treated.

Despite decades of clinical trials investigating new treatment modalities for glioblastoma multiforme (GBM), there have been no significant treatment advances since the 1980s. Reported median survival times for patients with GBM treated with current modalities generally range from 9 to 19 months. The purpose of the current study is to retrospectively review the ability of CyberKnife (Accuray Incorporated, Sunnyvale, CA, USA) radiosurgery to provide local tumor control of newly diagnosed or recurrent GBM. Twenty patients (43.5%) underwent CyberKnife treatment at the time of the initial diagnosis and/or during the first 3 months of their initial clinical management. Twenty-six patients (56.5%) were treated at the time of tumor recurrence or progression. CyberKnife was performed in addition to the traditional therapy. The median survival from diagnosis for the patients treated with CyberKnife as an initial clinical therapy was 11.5 months (range, 2-33) compared to 21 months (range, 8-96) for the patients treated at the time of tumor recurrence/progression. This difference was statistically significant (Kaplan-Meier analysis, P = 0.0004). The median survival from the CyberKnife treatment was 9.5 months (range, 0.25-31 months) and 7 months (range, 1-34 months) for patients in the newly diagnosed and recurrent GBM groups (Kaplan-Meier analysis, P = 0.79), respectively. Cox proportional hazards survival regression analysis demonstrated that survival time did not correlate significantly with treatment parameters (Dmax, Dmin, number of fractions) or target volume. Survival time and recursive partitioning analysis class were not correlated (P = 0.07). Patients with more extensive surgical interventions survived longer (P = 0.008), especially those who underwent total tumor resection vs. biopsy (P = 0.004). There is no apparent survival advantage in using CyberKnife in initial management of glioblastoma patients, and it should be reserved for patients whose tumors recur or progress after conventional therapy.