Gamma knife surgery for trigeminal neuralgia: outcomes and prognostic factors

Abstract

At the last follow up, GKS effected pain relief in 44% of patients. Some degree of pain improvement at 3 years post-GKS was noted in 70% of patients with TN. Although less effective than MVD, GKS remains a reasonable treatment option for those unwilling or unable to undergo more invasive surgical approaches and offers a low risk of side effects.

Gamma Knife stereotactic radiosurgical treatment of idiopathic trigeminal neuralgia: long-term outcome and complications

“…However, other clinical investigators have reported lower incidence rates of posttreatment facial numbness. 10,15,17,23,29 The development of numbness was slightly higher in the group of patients with previous surgery in our study. However, this difference was not statistically significant.…”

“…[4][5][6][12][13][14][15][30][31][32] The effect of the latency period after SRS in our study is comparable with the findings in previously reported series. 8,17,22,23,29,31 Interestingly, patients with previous surgery seem to be more frequently late responders to GKS than patients with no history of previous surgery. Our excellent and good outcome rates are comparable to those reported in previously published studies.…”

“…Significant variation exists in the prescribed radiation doses in previously published series. 1,3,13,17,28,29 It must be emphasized that the actual delivered dose might be different from the prescribed maximal dose from one GK unit to another due to variations in the output factor for the 4-mm collimator, 0.8-0.85, depending on the institution and medical physics techniques used to measure the output factor. 19 In addition, several other parameters such as advanced patient age, the presence of concomitant vasculopathy, systemic diseases such as multiple sclerosis, a small trigeminal cistern, and/or a history of previous radiosurgical treatments may lead to the use of a lower radiation dose.…”

“…8,16 Numerous authors have reported on SRS with the GK, and outcome and complication rates have been variable. [1][2][3][4][5][6]8,[10][11][12][13][14][15][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] The observed variation in success rates in the literature may be explained by the subjectivity of assessing pain (which is the most important outcome parameter in these studies), the multifactorial causes of TN (idiopathic or secondary to a pathological entity), the significantly varying stereotactic radiosurgical treatment protocols (different anatomical targets and different radiation doses), and the usage of illdefined and widely variable outcome assessment criteria.…”

Trigeminal Rhizotomy Performed with Modern Image-guided Linac: Case Report

“…By administering 60-90 Gy with a Co-60 source through a 4 mm aperture, the Gamma Knife has been shown to produce conformal isodose distributions and correspondingly excellent clinical results [3][4][5][6][7].…”