Park, Kyung-Jae MD, PhD*,‡; Kondziolka, Douglas MD*; Berkowitz, Oren RPA-C, MSPH*; Kano, Hideyuki MD, PhD*; Novotny, Josef Jr PhD*; Niranjan, Ajay MS, MCh*; Flickinger, John C. MD*; Lunsford, L. Dade MD*
Neurosurgery, 2012 Feb;70(2):295-305
Study Question: What is the efficacy of repeat radiosurgery on patients with recurrent trigeminal neuralgia?
Methods: Park et al. performed a retrospective study on 119 patients who were previously treated with the gamma knife for trigeminal neuralgia. Patients were treated with a median target dose for 70 Gy (dose ranging between 50 and 90 Gy). The endpoints used were pain relief according to the Barrow Neurological Institute pain score and facial sensory dysfunction.
Results: The authors reported that their median follow-up was 48 months (ranging between 6 and 187 months). Their median interval for treatment was 26 months. The authors reported that 87% of their patients experienced initial pain relief. At 1 year, 3 years, and 5 years, the pain relief rates were 87.8%, 69.8%, and 44.2%, respectively. The authors found that patients who presented with recurrent facial pain in a distribution smaller than their initial presentation had a more favorable prognosis. Facial sensory dysfunction rates were 21% within 18 months; however, facial sensory dysfunction was a favorable indicator for pain relief. The authors also found that having a higher dose of radiation to the brainstem correlated with sensory dysfunction.
Conclusion: Park et al. conclude that repeat radiosurgery for trigeminal neuralgia can be as effective as the initial treatment in terms of pain relief.
Perspective: Radiosurgery for trigeminal neuralgia was initially reserved for patients who were not good candidates for a microvascular decompression. However, there are an increasing number of patients with trigeminal neuralgia who are treated with radiosurgery. Given that radiosurgery is not as durable as a microvascular decompression for pain relief, there are an increasing number of patients who present with recurrent pain. Park et al. report that repeat treatments can be just as effective in pain control. However, the rate of facial sensory dysfunction is higher for the second treatment. Interestingly, for repeat treatments, sensory dysfunction appears to correlate with pain relief. Despite the fact that the rate of facial numbness is higher with a second treatment, the authors also point out that rhizotomies also carry a significant risk for facial sensory changes. Finally, the time to pain relief took 1.5 months which is similar to the latency for a first treatment. This paper suggests that we can safely use repeat radiosurgery for patients with recurrent TN.
Summary written by: Michael Lim