MedWire News: Cyberknife radiosurgery is a viable treatment for trigeminal neuralgia (TN), according to researchers at Winthrop-University Hospital in Mineola, New York, USA.
The team assessed the short-term efficacy of Cyberknife radiosurgery for potential use in patients with TN and found that around 90% of the patients responded to the treatment with at least partial relief of symptoms.
TN is characterized by attacks of sharp, shock-like pain within the trigeminal nerve distribution in the face. It affects 4- 5 people in every 100,000.
Current treatment for TN involves anticonvulsant and antidepressant medications, explain the researchers, progressing to surgical alternatives if these primary treatments fail. Stereotactic isocentric gamma knife and linear accelerator radiosurgery have been implemented to perform rhizotomy, but with notable side effects, they say.
"The Cyberknife system, on the other hand, delivers a non-isocentric beam of radiation better suited for targeting the trigeminal nerve with greater target fidelity and enhanced patient comfort," write Orlando Ortiz and colleagues. "These attributes hold promise for improved patient outcomes with fewer side effects."
Their study, published in the Journal of Interventional Surgery involved 16 patients who underwent radiosurgical rhizotomy using Cyberknife at a target 6-mm-long segment of the trigeminal nerve 2-3 mm distal to the dorsal root entry zone of the brainstem, at a maximum average dose of 73.06 Gy.
Overall, 14 (88%) of the patients responded favorably to the surgery, and their symptoms were either partially or fully relieved an average of 11.8 months after treatment, based on self-assessed degree of improvement of pain severity and frequency.
Seven patients were free of pain up until their last visit, an average of 5 months, and 11 patients were free of pain at some point during this period. Symptoms recurred in four patients at a range of time points following the Cyberknife surgery (3, 8, 9, and 18 months postsurgery).
Only two patients experienced side effects: one developed bothersome feathery dysesthesia and the other a nonbothersome mild jaw hypoesthesia. There were no substantial surgical complications.
The researchers say their results show that the dose and nerve length used produced "safe and effective outcomes," suggesting the approach is a suitable alternative to current therapies subject to further investigation.
They write: "The minimally invasive nature of radiosurgery is an attractive alternative with improving efficacy, particularly in those patients without vascular compression and as the first lesioning procedure. Further investigation and future comparative studies between Cyberknife, gamma knife and surgical treatment potentially will show Cyberknife's viable role in treating TN."
MedWire (http://www.medwire-news.md/) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
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