Results Of Gamma Knife Radiosurgery For Trigeminal Neuralgia Using A 90-gy Dose.L Abeloos1, Devriendt D1, Desmedt F1, David P1, De Witte O1, Massager N.11Gamma Knife Center, University Hospital Erasme, Brussels, Belgium. Keywords: pain, trigeminal neuralgia, gamma knife, outcome, dose planning
The use of a 90-Gy dose for Gamma Knife treatment of trigeminal neuralgia (TN) remains controversial.
We evaluate pain relief and morbidity in a series of patients treated by Gamma Knife for TN using for all patients a 90-Gy radiation dose, standardized dosimetric parameters (distance and dose delivered to the brainstem) and irradiation with LGK-C.
We treated 204 patients for TN in our Gamma Knife center.
We treated the patients using a standardized methodology: 1) targeting using axial 1-mm sliced Gadolinium-enhanced T1-weighted and T2-weighted MRI); 2) distance of nerve >5mm between target and brainstem; 3) maximum radiation dose of 15 Gy delivered at the first 10mm³ of the brainstem; 4) maximum prescription dose of 90 Gy; 5) irradiation with LGK-C with APS. Patients were followed clinically for pain relief and complications; a minimum follow-up of 1 year was request to be included in the study.
The follow-up data of 165 patients was available for analysis; mean follow-up was 24 months. Plugs were used for 59 patients (35%). Complete (100%) pain relief was reached for 123 patients (75%), 90% to 99% pain reduction for 21 patients (13%), 50% to 89% pain reduction for 8 patients (5%). No significant improvement of trigeminal pain following Gamma Knife treatment occurred in 13 patients (8%). A total of 143 patients (87%) have reduced or stopped their medication for TN at last follow-up. Moderate facial numbness occurred in 46 patients (28%) and bothersome dysesthesia in 19 patients (11%), including 11 patients treated with plugs. No other complication was observed.
This is a retrospective study.
Our dosimetric parameters achieved high rate of initial pain relief.
However, our treatment protocol is associated with a significant risk of numbness or bothersome dysesthesia, especially when plugs are used. We do not recommend using plugs when a 90-Gy dose is used. Project Roles:
L. Abeloos (), D. D (), D. F (), D. P (), D. O (), M. N. ()