Original ArticleFrameless Stereotactic Radiosurgery for Treatment of Multiple Sclerosis–Related Trigeminal Neuralgia
Introduction
Trigeminal neuralgia (TN) is the most common craniofacial pain syndrome, with an incidence of up to 5 in 100,000. It is a severe condition requiring long-term medical treatment. Nonetheless, up to 10% of patients suffer major adverse drug-related events and require some type of surgical treatment.1, 2 About 1%–2% of TN cases are caused by demyelinating plaques of multiple sclerosis (MS) along the trigeminal pathway, nerve, and brainstem. Trigeminal pain affects up to 7% of patients with MS, and symptoms are often atypical or bilateral.3 In such patients, TN is often difficult to manage either pharmacologically or surgically, with lower response rates than idiopathic TN.4, 5, 6
Pioneered by Lars Leksell in 1951,7 stereotactic radiosurgery is a proven and valuable method to treat TN. A remarkable body of experience is available in the use of Gamma Knife single isocenter treatments of TN.8, 9, 10, 11, 12, 13, 14, 15, 16 On the other hand, only a handful of dedicated studies about the treatment of MS-related TN are available to date.17, 18, 19, 20, 21, 22, 23 Whether the radiosurgical rhizotomy for TN can be performed using a frameless technique is often questioned. The CyberKnife (Accuray Inc., Sunnyvale, California, USA), a frameless robotic system,24, 25, 26 has been proposed for the treatment of functional disorders. The nonisocentric geometry of radiation beam delivery provides the possibility of homogeneous irradiation of an extended segment of the trigeminal nerve, thus introducing new concepts for the radiosurgical treatment of TN. Despite the limited number of series reported to date, clinical results of CyberKnife radiosurgery seem to be satisfactory. Whether frameless radiosurgery can be successfully applied to patients with TN secondary to MS has yet to be demonstrated. We report our results on this issue.
Section snippets
Patients' Selection
Between September 2009 and November 2015, we treated and followed up 27 patients presenting with medically intractable TN and MS at the CyberKnife Center, University of Messina, Italy. Patients fulfilling the criteria of the International Headache Society (2003)27 were included. Evaluation of the type of trigeminal pain was made according to the classification proposed by Eller et al28 into idiopathic TN1 and TN2. Patients were categorized as having TN1 (typical) if pain was described as
Target and Treatment Data
All treatments were performed in a single session. Median prescription isodose line (80%) accounting for a dose of 58 Gy incorporated an average of 4.85 mm (4 to 6 mm) segment of the trigeminal nerve, with a mean nerve volume of 26.4 mm3 (range 20–38 mm3) (Figure 2). The median maximal dose was 72.5 Gy (range, 71.8–Gy74.4). Median number of beams was 105 (range 90–110); median number of nodes was 87 (range 85–90). Treatment time ranged 45–55 minutes with beam-on time ranging 15–21 minutes. The
Discussion
In our series, the first on the use of frameless, nonisocentric radiosurgery technique to treat MS-related TN, we observed initial pain relief in 85% of the patients. This result is consistent with the data of Gamma Knife radiosurgery for idiopathic TN, in which initial pain relief has been reported in 50%–96%.8, 9, 10, 12, 16, 30 Overall, the studies specifically addressing the use of radiosurgery for TN cases associated with MS report clinically relevant benefits in 57%–100% of the patients17
References (47)
Fitting radiosurgery into the trigeminal neuralgia management puzzle
World Neurosurg
(2010)- et al.
Comparison of percutaneous retrograsserian balloon compression and Gamma Knife radiosurgery for the treatment of trigeminal neuralgia in multiple sclerosis: a clinical research study article
World Neurosurg
(2017) - et al.
Long-term outcome of Gamma Knife stereotactic radiosurgery for multiple sclerosis associated trigeminal neuralgia
Int J Radiat Oncol Biol Phys
(2010) - et al.
Gamma Knife radiosurgery for trigeminal neuralgia: the initial experience of The Barrow Neurological Institute
Int J Radiat Oncol Biol Phys
(2000) - et al.
Long-term outcome of Gamma Knife radiosurgery for treatment of typical trigeminal neuralgia
Int J Radiat Oncol Biol Phys
(2009) - et al.
CyberKnife stereotactic radiosurgical rhizotomy for refractory trigeminal neuralgia
J Clin Neurosci
(2011) - et al.
Outcomes of Gamma Knife radiosurgery for trigeminal neuralgia after a minimum 3-year follow-up
J Clin Neurosci
(2011) - et al.
Dedicated linear accelerator radiosurgery for trigeminal neuralgia: a single-center experience in 179 patients with varied dose prescriptions and treatment plans
Int J Radiat Oncol Biol Phys
(2011) - et al.
Repeat Gamma Knife radiosurgery for trigeminal neuralgia
Int J Radiat Oncol Biol Phys
(2011) - et al.
Toxicity of Gamma Knife radiosurgery in the treatment of intracranial tumors in patients with collagen vascular diseases or multiple sclerosis
Int J Radiat Oncol Biol Phys
(2011)
Trigeminal neuralgia and its management
BMJ
Treatment options in trigeminal neuralgia
Ther Adv Neurol Disord
On the natural history of trigeminal neuralgia
Neurosurgery
Operative findings and outcomes of microvascular decompression for trigeminal neuralgia in 35 patients affected by multiple sclerosis
Neurosurgery
Percutaneous controlled radiofrequency rhizotomy in the management of patients with trigeminal neuralgia due to multiple sclerosis
Acta Neurochir (Wien)
Long-term results after glycerol rhizotomy for multiple sclerosis-related trigeminal neuralgia
Can J Neurol Sci
Sterotaxic radiosurgery in trigeminal neuralgia
Acta Chir Scand
Gamma Knife stereotactic radiosurgery for idiopathic trigeminal neuralgia
J Neurosurg
Predictive variables for the successful treatment of trigeminal neuralgia with Gamma Knife radiosurgery
Neurosurgery
Gamma Knife surgery for idiopathic trigeminal neuralgia performed using a far-anterior cisternal target and a high dose of radiation
J Neurosurg
Prospective controlled trial of Gamma Knife surgery for essential trigeminal neuralgia
J Neurosurg
Outcomes following single-treatment Gamma Knife surgery for trigeminal neuralgia with a minimum 3-year follow-up
J Neurosurg
Gamma Knife surgery for trigeminal neuralgia: outcomes and prognostic factors
J Neurosurg
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Conflict of interest statement: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.