Stereotactic radiosurgery for trigeminal neuralgia: a systematic review

Abstract

OBJECTIVES The aims of this systematic review are to provide an objective summary of the published literature specific to the treatment of classical trigeminal neuralgia with stereotactic radiosurgery (RS) and to develop consensus guideline recommendations for the use of RS, as endorsed by the International Society of Stereotactic Radiosurgery (ISRS). METHODS The authors performed a systematic review of the English-language literature from 1951 up to December 2015 using the Embase, PubMed, and MEDLINE databases. The following MeSH terms were used in a title and abstract screening: "radiosurgery" AND "trigeminal." Of the 585 initial results obtained, the authors performed a full text screening of 185 studies and ultimately found 65 eligible studies. Guideline recommendations were based on level of evidence and level of consensus, the latter predefined as at least 85% agreement among the ISRS guideline committee members. RESULTS The results for 65 studies (6461 patients) are reported: 45 Gamma Knife RS (GKS) studies (5687 patients [88%]), 11 linear accelerator (LINAC) RS studies (511 patients [8%]), and 9 CyberKnife RS (CKR) studies (263 patients [4%]). With the exception of one prospective study, all studies were retrospective. The mean maximal doses were 71.1-90.1 Gy (prescribed at the 100% isodose line) for GKS, 83.3 Gy for LINAC, and 64.3-80.5 Gy for CKR (the latter two prescribed at the 80% or 90% isodose lines, respectively). The ranges of maximal doses were as follows: 60-97 Gy for GKS, 50-90 Gy for LINAC, and 66-90 Gy for CKR. Actuarial initial freedom from pain (FFP) without medication ranged from 28.6% to 100% (mean 53.1%, median 52.1%) for GKS, from 17.3% to 76% (mean 49.3%, median 43.2%) for LINAC, and from 40% to 72% (mean 56.3%, median 58%) for CKR. Specific to hypesthesia, the crude rates (all Barrow Neurological Institute Pain Intensity Scale scores included) ranged from 0% to 68.8% (mean 21.7%, median 19%) for GKS, from 11.4% to 49.7% (mean 27.6%, median 28.5%) for LINAC, and from 11.8% to 51.2% (mean 29.1%, median 18.7%) for CKR. Other complications included dysesthesias, paresthesias, dry eye, deafferentation pain, and keratitis. Hypesthesia and paresthesia occurred as complications only when the anterior retrogasserian portion of the trigeminal nerve was targeted, whereas the other listed complications occurred when the root entry zone was targeted. Recurrence rates ranged from 0% to 52.2% (mean 24.6%, median 23%) for GKS, from 19% to 63% (mean 32.2%, median 29%) for LINAC, and from 15.8% to 33% (mean 25.8%, median 27.2%) for CKR. Two GKS series reported 30% and 45.3% of patients who were pain free without medication at 10 years. CONCLUSIONS The literature is limited in its level of evidence, with only one comparative randomized trial (1 vs 2 isocenters) reported to date. At present, one can conclude that RS is a safe and effective therapy for drug-resistant trigeminal neuralgia. A number of consensus statements have been made and endorsed by the ISRS.

Factors affecting outcome in frameless non-isocentric stereotactic radiosurgery for trigeminal neuralgia: a multicentric cohort study

“…Furthermore, re-irradiation and presence of MS were independent predictors of the occurrence of numbness. The results of this series in terms of pain relief are consistent with those previously reported and suggest that image-guided robotic radiosurgery represents an effective treatment of TN [7,8,10,17]. Our results are indeed slightly superior to those previously published by Romanelli et al (n = 138 pts.…”

“…Alternative techniques aim to modulate the trigeminal nociceptive pathways either by percutaneous lesioning of the Gasserian ganglion or by irradiation of the cisternal portion of the nerve using stereotactic radiosurgery (SRS) [1,6,7]. Clinical experience regarding TN treatment using SRS is based mainly on single isocenter Gamma knife radiosurgery (GKS) treatments [8]. Typically GKS results in up to 92% pain relief within 12 months; however, the pain relapse rate during follow-up is remarkable [9][10][11][12][13][14][15][16][17].…”

Chronic Facial Pain: Trigeminal Neuralgia, Persistent Idiopathic Facial Pain, and Myofascial Pain Syndrome—An Evidence-Based Narrative Review and Etiological Hypothesis

“…The preferred target for GKRS has evolved from the trigeminal ganglion itself to the retrogasserian region and to the root entry zone. A meta-analysis of GKRS outcomes reported that pain relief ranged from 69 to 85% at one year, falling to 38 to 52% at 5 years and 30 to 45.3% at 10 years [ 56 , 68 ]. Onset of pain relief is delayed, ranging from 15 to 78 days on average, up to 6 months.…”

Gamma Knife Radiosurgery for Short Unilateral Neuralgiform Headache Attacks with Conjunctival Injection and Tearing (SUNCT) Syndrome: Targeting the Trigeminal Nerve and the Sphenopalatine Ganglion. Case Report and Literature Review

“…In recent years, the technique has been refined and great care is taken to target the precise area to be treated to optimize pain control and minimize complications. 16 It has been reported that a lesion close to the root exit zone of the TN is very effective on pain, although this type of lesion carries the possibility of unpleasant collateral symptoms (hypoesthesia). Therefore, when feasible and depending on intracisternal TN length, the isocenter should be located distally from the brainstem 16 ; doses generally used for these treatments range between 80 and 90 Gy (maximal dose).…”