Early clinical experience of using the Surpass Evolve flow diverter in the treatment of intracranial aneurysms.

PURPOSE: Here, we presented our early experience with flow diversion procedures using the Surpass Evolve flow diverter (SE, Stryker) and reported the feasibility and safety profile compared to those of a control group treated with other types of flow diverters. METHODS: We included 31 and 53 consecutive flow diversion procedures performed using the SE and other commercial flow diverters, respectively, to treat intracranial aneurysms at our institution. We used two commercial flow diversion systems in the comparison group: the pipeline embolization device and Surpass Streamline. RESULTS: In the SE group, technical failures occurred in three (9.7%) cases, due to either incomplete wall apposition (n = 1, 3.2%) or stent migration (n = 2, 6.5%). Major complications occurred in four (12.9%) cases: delayed rupture of the target aneurysm (n = 1, 3.2%), major ischemic stroke (n = 1, 3.2%), sudden death from an unidentified cause (n = 1, 3.2%), and parent artery occlusion with stent thrombosis (n = 1, 3.2%). Balloon angioplasty was performed in eight (25.8%) cases. On post-procedure MRI, a DWI-positive lesion was detected in three (9.7%) cases. After multivariate adjustment, the SE group was independently associated with less procedural time of ≥ 90 min (adjusted OR, 0.09; 95% CI, 0.03-0.29; p < 0.001), balloon angioplasty (adjusted OR, 0.22; 95% CI, 0.07-0.75; p = 0.015), and DWI-positive lesions (adjusted OR, 0.04; 95% CI, 0.01-0.19; p < 0.001). CONCLUSION: The SE is safe and easy to deploy.

Postoperative complications of microvascular decompression for hemifacial spasm: lessons from experience of 2040 cases.

Microvascular decompression (MVD) is an effective and safe treatment option that offers the prospect of definitive cure for hemifacial spasm (HFS). However, there are potential risks of complications for MVD associated with retromastoid suboccipital craniectomy (RmSOC) and cranial nerves in particular. The purpose of this study was to identify clinical characteristics of possible complications after MVD for HFS and to establish appropriate management concept of these complications. We retrospectively reviewed medical records of 2040 patients who underwent RmSOC with MVD for HFS at Samsung medical center between January 1998 and March 2013. Of 2040 patients, 2027 were followed (99.4%). Of the 2027 patients, 1841 (90.8%) exhibited complete relief or minimal symptoms, and 113 (5.6%) reported improved spasm but had mild remnant symptoms. After operation, the most frequently developed complications were facial nerve palsy (8.19%), followed by middle ear effusion (4.90%) and hearing loss (3.63%). There were two cases of supratentorial subdural hemorrhage, three cases of infarction. MVD was found to be safe and effective treatment for HFS, in consistent with previous reports. Some of the complications such as facial nerve palsy, middle ear effusion, and hearing loss are relatively common. However, they have mild clinical courses that are usually transient.

Cerebellar retraction and hearing loss after microvascular decompression for hemifacial spasm.

BACKGROUND: This retrospective study evaluated the length of cerebellar retraction and the changes of intraoperative brainstem auditory evoked potential (BAEP) during microvascular decompression (MVD), and assessed the predictive value of the hearing loss as a prognostic indicator for the treatment outcome of hemifacial spasm (HFS). METHODS: This series included 1,518 consecutive patients affected with HFS who underwent MVD, during which BAEP was monitored. Patients were divided into two groups based on whether hearing loss occurred following decompression or not. Each patient underwent a similar procedure performed by one neurosurgeon. The two patients groups were matched with regard to sex, age, and degree of spasm. RESULTS: Among the 1,518 patients, 106 (6.98 %) displayed functional hearing changes. Hearing loss was permanent in 12 patients (0.79 %). Of the 1,412 patients with stationary hearing compared with preoperative audiometry, 96 patients were selected who were individually matched with respect to sex, age, and degree of spasm. BAEP changed immediately after cerebellar retraction in 7 of 12 hearing-loss patients, suggesting the importance of retraction on hearing outcomes. The distance from the cerebellar surface of the petrous temporal bone to the neurovascular compression point was measured. The median distance of cerebellar retraction in the hearing-loss group was 13.77 mm, which was longer than the median distance in the control group. CONCLUSIONS: Preoperative measurement of the cerebellar retraction distance can be a valuable clue to predict and prevent postoperative hearing loss in MVD for HFS.

Outcome of conventional treatment and prognostic factor in elderly glioblastoma patients.

BACKGROUND: Glioblastoma (GBM) is the most life-threatening primary brain tumour. Especially in elderly patients, a poorer outcome is noticeable. Until now, the effectiveness of the conventional active treatment has been controversial. The purpose of this study is to find the optimal treatment for elderly patients with newly diagnosed GBM. METHOD: The authors retrospectively reviewed 301 patients who were diagnosed with GBM at a single centre from January 2006 to December 2010. All patients were divided into younger and elderly groups based on the cut-off age of 65 years, and the treatment outcome was analysed. RESULTS: Of 301 patients, 67 (23.3 %) patients were 65 years old or older, and 234 (77.7 %) patients were younger than 65 years. In the elderly group, 49 patients received surgical resection and 18 patients received biopsy. Forty-seven patients (70.1 %) underwent concomitant chemoradiotherapy (CCRT) and 38 patients (56.7 %) underwent adjuvant temozolomide (TMZ) chemotherapy. The median overall survival (OS) of elderly patients was 12.0 months and the progression-free survival (PFS) was 8.5 months. The median OS of elderly patients who underwent CCRT and adjuvant TMZ chemotherapy increased to 16.2 months. On the multivariate analysis, tumour infiltration (p = 0.005), and resection (p = 0.001) were significant independent prognostic factors in elderly patients. The grade 3 or 4 complication rate was not statistically different between the younger group (n = 22, 9.4 %) and the elderly group (n = 8, 12 %). CONCLUSION: Elderly patients diagnosed with GBM had a survival benefit and a low complication rate with the conventional treatment. Therefore, elderly patients should be encouraged to receive the conventional active treatment.

Evaluation of the Significance of Persistent Remnant Filling and Enlargement After Flow Diversion for Intracranial Aneurysms.

BACKGROUND: This study aimed to evaluate the clinical course after flow diversion (FD) treatment with a focus on aneurysms with remnant sac filling, by analyzing angiographic outcomes, aneurysm volume, and clinical events. METHODS: We retrospectively reviewed the medical records of 61 patients who underwent FD for intracranial aneurysms between July 2014 and June 2021. RESULTS: The majority of aneurysms (52.5%) were located in the internal carotid artery, with a median diameter of 16.6 mm and neck size of 9.3 mm. Remnant filling was observed in 17 aneurysms (27.9%) more than 18 months after FD, 10 (16.4%) of these aneurysms underwent enlargement, which occurred only in cases with subtotal filling or entry remnant states. Eleven patients experienced major adverse events, and three exhibited unfavorable functional outcomes. The incidence of major adverse events and unfavorable functional outcomes was significantly higher in the aneurysm enlargement group than that in the no-filling or stable remnant filling groups (P < 0.001). Aneurysmal diameter and the presence of incorporated branches were independent predictors of aneurysm enlargement, while the presence of incorporated branches was the only independent predictor of persistent remnant filling. CONCLUSIONS: Aneurysm enlargement after FD is not uncommon, particularly when the aneurysm is large, has incorporated vessels, or does not undergo occlusion within 12 months, often culminating in major adverse events and unfavorable functional outcomes. In addition to investigating angiographic results, it is necessary to evaluate the changes in aneurysm size and clinical events when assessing the efficacy of FD.

Comparing the safety and effectiveness of overlapping stents with flow diverters for unruptured vertebral artery dissecting aneurysms.

BACKGROUND: Endovascular treatment for vertebral artery dissecting aneurysms (VADAs) includes overlapping stents and flow diverters. This study compared the safety and effectiveness of overlapping stents and flow diverters for unruptured VADAs. METHODS: We retrospectively enrolled patients with unruptured VADAs who underwent overlapping stents or flow diverters at two tertiary hospitals in South Korea. The primary clinical outcome was the occurrence of stroke. The primary angiographic outcomes (>12 months) were categorized as regression, no decrease in size, recanalization, or stent occlusion, of which only regression was defined as a favorable angiographic outcomes. RESULTS: Of the 146 patients with VADAs, 25 (17.1%) had flow diverters and 121 (82.9%) had overlapping stents. For the primary angiographic outcomes over 12 months, the rate of favorable angiographic outcomes for flow diverters was 81.8% and for overlapping stents (triple stents) was 98.8% (P=0.006). In the multivariale analysis, after adjusting for partially thrombosed aneurysms, aneurysm shape, non-dominant vessel, posterior inferior cerebellar artery involvement, and procedure type, overlapping stents (triple stents) was not associated with favorable angiographic outcomes compared with flow diverters (OR 7.040, 95% CI 0.549 to 90.294; P=0.134), but partially thrombosed aneurysms was inversely associated with favorable angiographic outcomes (OR 0.056, 95% CI 0.005 to 0.589; P=0.016). The primary clinical outcome followed up to the last angiography did not occur in all patients. CONCLUSION: There was no difference in safety and effectiveness between overlapping stents and flow diverters in unruptured VADAs. Further endovascular treatment studies are needed regarding the association of partially thrombosed aneurysms with unfavorable angiographic outcomes.

Surgical Strategy for Ethmoidal Dural Arteriovenous Fistula.

OBJECTIVE: Ethmoidal dural arteriovenous fistula (DAVF) is a rare type of intracranial DAVF. The aim of this study was to report our experience with a unilateral approach and discuss its effectiveness for ethmoidal DAVF treatment. METHODS: The study included 19 patients who underwent surgical treatment for ethmoidal DAVF between January 1999 and May 2021. RESULTS: Median age of patients was 59.7 years; 16 (84%) patients were male. Three patients had a ruptured ethmoidal DAVF. Preoperative digital subtraction angiography showed that all ethmoidal DAVFs were supplied by the bilateral external carotid artery branches. In 18 (95%) patients, cortical draining veins were located on the unilateral side. Bilateral lesions were identified in only 1 (5%) patient. The frontobasal approach was performed in 5 patients (26%), the pterional approach was performed in 5 (26%) patients, and the lateral supraorbital approach was performed in 9 (47%) patients; median procedural times were 198 minutes, 172 minutes, and 111 minutes, respectively. Cortical draining vein was successfully disconnected in all 19 patients with 20 ethmoidal DAVFs. Complete obliteration of ethmoidal DAVF was confirmed in all patients, with no postoperative complications. No recurrence or related clinical events were reported in 13 (68%) patients over 12 months of clinical and radiological follow-up. CONCLUSIONS: We reconfirmed excellent outcomes of surgical treatment for ethmoidal DAVFs. Three different surgical strategies were attempted, and each had pros and cons. The lateral supraorbital approach is an efficient surgical option for unilateral ethmoidal DAVFs. Careful preoperative examination for the presence of bilateral drainage is essential.

Vessel Wall Changes on Serial High-Resolution MRI and the Use of Cilostazol in Patients With Adult-Onset Moyamoya Disease.

BACKGROUND AND PURPOSE: The natural course of adult-onset moyamoya disease (MMD) is unknown, and there is no medical treatment that halts its progression. We hypothesized that progressive shrinkage of large intracranial arteries occurs in adult-onset MMD, and that cilostazol inhibits this process. METHODS: Serial high-resolution magnetic resonance imaging (HR-MRI) was performed on 66 patients with MMD: 30 patients received cilostazol, 21 received other antiplatelets, and 15 received no antiplatelets or had poor compliance to them. Serial HR-MRI was performed (interval between MRI scans: 29.67±18.02 months, mean±SD), and changes in outer diameter, luminal stenosis, and vascular enhancement were measured. Factors affecting HR-MRI changes were evaluated, including vascular risk factors and the ring finger protein 213 gene variant. RESULTS: The progression of stenosis to occlusion, recurrent ischemic stroke, and the development of new stenotic segments were observed in seven, seven, and three patients, respectively. Serial HR-MRI indicated that the degree of stenosis increased with negative remodeling (outer diameter shrinkage). Patients who received cilostazol presented significantly larger outer diameters and lower degrees of stenosis compared with other groups (p=0.005 and p=0.031, respectively). After adjusting for clinical and genetic factors, only cilostazol use was independently associated with negative remodeling (odds ratio=0.29, 95% confidence interval=0.10-0.84, p=0.023). While vascular enhancement was observed in most patients (61 patients), the progression of enhancement or the occurrence of new vascular enhancement was rarely observed on follow-up HR-MRI (6 and 1 patients, respectively). CONCLUSIONS: Adult-onset MMD induces progressive shrinkage of large intracranial arteries, which cilostazol treatment may prevent. Further randomized clinical trials are warranted. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02074111.

Treatment Outcomes After Single-Device Flow Diversion for Large or Giant Aneurysms.

OBJECTIVE: We aimed to evaluate the efficacy and safety of single-device flow diversion in patients with aneurysms measuring ≥15 mm in diameter. METHODS: For this retrospective study, we extracted medical record data for patients with unruptured intracranial aneurysms, who underwent flow diversion, at the authors' institution between July 2014 and August 2019. The primary effectiveness outcome was defined as angiographic occlusion of the target aneurysm within 18 months without major (>50%) parent artery stenosis, major adverse events, or additional treatment. RESULTS: Thirty-five aneurysms in 35 patients were analyzed. Most aneurysms (n = 29, 82.9%) involved the anterior circulation. The median aneurysmal diameter was 18.3 mm, and the median neck size was 7.6 mm. Eleven (31.4%) aneurysms were considered giant (≥25 mm). The primary effectiveness outcome was achieved in 20 (57.1%) patients at a median of 10 months (interquartile range, 4.3-12.5) after flow diversion. Major adverse events occurred in 6 (17.1%) patients, including remote intraparenchymal hemorrhages (n = 2), a major ischemic stroke (n = 1), a delayed rupture of the target aneurysm (n = 1), and clinical deterioration caused by aggravated mass effect (n = 2). Multivariate logistic regression analysis found 2 independent predictors of the primary effectiveness outcome: the aneurysmal diameter (odds ratio, 0.71; 95% confidence interval, 0.54-0.86; P = 0.004) and the parent-vessel angle (odds ratio, 0.97; 95% confidence interval, 0.93-0.99; P = 0.017). CONCLUSIONS: Single-device flow diversion was shown to be ineffective for large or giant intracranial aneurysms with a high parent vessel angle.

How Cerebral Vessel Tortuosity Affects Development and Recurrence of Aneurysm: Outer Curvature versus Bifurcation Type.

BACKGROUND AND PURPOSE: Previous studies have assessed the relationship between cerebral vessel tortuosity and intracranial aneurysm (IA) based on two-dimensional brain image analysis. We evaluated the relationship between cerebral vessel tortuosity and IA according to the hemodynamic location using three-dimensional (3D) analysis and studied the effect of tortuosity on the recurrence of treated IA. METHODS: We collected clinical and imaging data from patients with IA and disease-free controls. IAs were categorized into outer curvature and bifurcation types. Computerized analysis of the images provided information on the length of the arterial segment and tortuosity of the cerebral arteries in 3D space. RESULTS: Data from 95 patients with IA and 95 controls were analyzed. Regarding parent vessel tortuosity index (TI; P<0.01), average TI (P<0.01), basilar artery (BA; P=0.02), left posterior cerebral artery (P=0.03), both vertebral arteries (VAs; P<0.01), and right internal carotid artery (P<0.01), there was a significant difference only in the outer curvature type compared with the control group. The outer curvature type was analyzed, and the occurrence of an IA was associated with increased TI of the parent vessel, average, BA, right middle cerebral artery, and both VAs in the logistic regression analysis. However, in all aneurysm cases, recanalization of the treated aneurysm was inversely associated with increased TI of the parent vessels. CONCLUSIONS: TIs of intracranial arteries are associated with the occurrence of IA, especially in the outer curvature type. IAs with a high TI in the parent vessel showed good outcomes with endovascular treatment.

Intracranial Aneurysms in Young Adult Patients: Surgical and Endovascular Treatment Outcomes.

BACKGROUND: Despite its relative rarity, the potential for loss of productive years makes aneurysmal subarachnoid hemorrhage (SAH) a considerably important entity in young adult patients (20-39 years of age). This study aimed to analyze outcomes of microsurgery (MS) and endovascular treatment (EVT) for saccular intracranial aneurysms (IAs) in young adult patients. METHODS: A total of 276 young adult patients with 315 IAs, treated with MS or EVT between January 2001 and December 2015, were studied. Major recurrence and treatment-related complications were the primary outcome measures. Functional outcomes in patients with SAH were also assessed. RESULTS: Major recurrence occurred in 21 cases (6.7%). Younger age (adjusted hazard ratio [aHR], 3.77; 95% confidence interval [CI], 1.45-9.83; P = 0.007), ruptured IA (aHR, 6.44; 95% CI, 2.09-19.89; P = 0.001), size (aHR, 1.84; 95% CI, 1.06-3.18; P = 0.030), and EVT (aHR, 7.21; 95% CI, 2.44-21.35; P < 0.001) were independently related to major recurrence. Treatment-related complications occurred in 5 cases (1.6%) and did not differ between the MS and EVT groups (P > 0.999). Unfavorable outcomes (modified Rankin scale score ≥2) were identified in 30 patients (19.6%) with SAH, and only Hunt and Hess grade was independently associated with unfavorable functional outcome. CONCLUSIONS: Both MS and EVT are safe for treating IAs in young adult patients. MS showed better durability of treatment and may be preferred over EVT in young patients in view of their longer life expectancy compared with older patients.

Prospective Screening of Extracranial Systemic Arteriopathy in Young Adults with Moyamoya Disease.

Background RNF213 is a major susceptibility gene for moyamoya disease (MMD), characterized by chronic progressive steno-occlusion of the intracranial arteries. However, coincidental extracranial arteriopathy is sporadically described in a few cases and in children with MMD. Methods and Results This study prospectively enrolled 63 young adults (aged 20-49 years) without a known history of systemic vascular diseases who were confirmed to have definite (bilateral, n=54) or probable (unilateral, n=9) MMD, as per typical angiographic findings. Coronary and aorta computed tomography angiography was performed to characterize extracranial arteriopathy and investigate its correlation with clinical characteristics and MMD status, including the RNF213 p.Arg4810Lys variation (c.14429G>A, rs112735431). Altogether, 11 of 63 patients (17%) had significant (>50%) stenosis in the coronary (n=6), superior mesenteric (n=2), celiac (n=2), renal (n=1), and/or internal iliac artery (n=1). One patient showed both mesenteric and iliac artery stenosis. Patients with extracranial arteriopathy were more likely to have diabetes mellitus and posterior cerebral artery involvement. Moreover, a higher prevalence of extracranial arteriopathy was observed in the presence of the RNF213 p.Arg4810Lys variant (67% in homozygotes). After controlling for diabetes mellitus and posterior cerebral artery involvement, the p.Arg4810Lys variant was independently associated with extracranial arteriopathy (additive model; P=0.035; adjusted odds ratio, 4.57; 95% CI, 1.11-27.20). Conclusions Young adults with MMD may have concomitant extracranial arteriopathy in various locations. Patients with RNF213 variants, especially the p.Arg4810Lys homozygous variant, should be screened for systemic arteriopathy.

Idiopathic hypertrophic spinal pachymeningitis with an osteolytic lesion.

Idiopathic hypertrophic spinal pachymeningitis (IHSP) is a chronic, progressive, inflammatory disorder characterized by marked fibrosis of the spinal dura mater with unknown etiology. According to the location of the lesion, it might induce neurologic deficits by compression of spinal cord and nerve root. A 58-year old female with a 3-year history of progressive weakness in both lower extremities was referred to our institute. Spinal computed tomography (CT) scan showed an osteolytic lesion involving base of the C6 spinous process with adjacent epidural mass. Magnetic resonance imaging (MRI) revealed an epidural mass involving dorsal aspect of cervical spinal canal from C5 to C7 level, with low signal intensity on T1 and T2 weighted images and non-enhancement on T1 weighted-enhanced images. We decided to undertake surgical exploration. At the operation field, there was yellow colored, thickened fibrous tissue over the dura mater. The lesion was removed totally, and decompression of spinal cord was achieved. Symptoms improved partially after the operation. Histopathologically, fibrotic pachymeninges with scanty inflammatory cells was revealed, which was compatible with diagnosis of idiopathic hypertrophic pachymeningitis. Six months after operation, motor power grade of both lower extremities was normal on physical examination. However, the patient still complained of mild weakness in the right lower extremity. Although the nature of IHSP is generally indolent, decompressive surgery should be considered for the patient with definite or progressive neurologic symptoms in order to prevent further deterioration. In addition, IHSP can present as an osteolytic lesion. Differential diagnosis with neoplastic disease, including giant cell tumor, is important.

Spinal metastasis of thymic carcinoma as a rare manifestation: a summary of 7 consecutive cases.

BACKGROUNDS: Thymic carcinomas are very rare tumors that are often associated with extrathoracic metastasis to other organs. However, it is well known that thymic carcinomas rarely metastasize to the spine, and the prognosis, treatment, and natural course of this disease are not yet standardized. METHODS: We describe seven thymic carcinoma patients with spinal metastasis who were diagnosed and treated in our institute from January 2006 to December 2011. We performed surgical treatment and adjuvant chemotherapy and/or radiation therapy, in consideration of each individual disease's course, and we regularly followed up the patients. RESULTS: Of the seven patients, five were male and two were female. Six had metastases in the thoracic spine, and one had metastases in the lumbar spine. An extradural lesion was found in five patients, and two patients had both extradural and intradural lesions. The period from the primary diagnosis to spinal metastases varied widely (range, 1.23-14 years). After surgery, all patients showed an improvement of back pain and radicular pain. Two patients were lost to follow-up, but the other five maintained ambulatory function until their final follow-up. Four patients died because of pulmonary complications accompanied with the disease's progression. One patient died from uncontrolled brain metastases. After surgery, the median survival was 204±111.43 days. CONCLUSION: Because metastasis to the spine from thymic carcinoma is very rare, there are no treatment guidelines. Nevertheless, we suggest that appropriate surgical management of the metastatic lesion is necessary for the preservation of the patient's quality of life during survival.

Clinical features and treatment outcome of chordoid meningiomas in a single institute.

OBJECTIVE: Meningioma is the second most common primary central nervous system neoplasm. In contrast, chordoid meningioma is rare; due to the paucity of cases, little is known about its clinical features or treatment outcomes. The objectives of this study were to describe the clinical characteristics and outcomes for patients with chordoid meningioma. METHODS: In total, 16 patients, with newly diagnosed chordoid meningioma who underwent surgical excision between 1999 and 2012 were included. We retrospectively evaluated the medical records, radiological findings, and pathological findings. The median follow-up period was 56.5 (range, 3-170) months. The MIB-1 labeling index ranged from 1 to 26.60% (median, 5.04). RESULTS: Simpson grade I, II, and III resections were performed in four, nine, and three patients, respectively. The overall recurrence rate was 37.5%. Overall progression-free survival (PFS) after resection was 94.7 months (95% CI=62.9-126.6). Of the 4 patients with Simpson grade I resection, recurrence occurred in one patient. Among the Simpson grade II and III resection groups, eight patients underwent adjuvant radiation therapy and they showed significantly longer PFS (121 months, 95% CI=82.1-159.9) than the patients who underwent surgery alone (40.5 months, 95% CI=9.6-71.3) by the log-rank test (p<0.05). CONCLUSION: Chordoid meningiomas are difficult to manage and have a high rate of recurrence. Complete resection of the tumor is a key determinant of better outcomes. Adjuvant radiation therapy is recommended, eparticulary when Simpson grade I resection was not achieved.

Fractionated gamma knife radiosurgery for benign perioptic tumors: outcomes of 38 patients in a single institute.

BACKGROUND: This study was performed to evaluate the efficacy and safety of fractionated Gamma Knife radiosurgery (GKRS) for perioptic lesions. METHODS: Thirty-eight patients with perioptic tumors were treated at our institute from May 2004 to December 2008. All patients had a lesion in close contact with the optic apparatus. Twenty-four of these patients had undergone surgical resection before fractionated GKRS. Radiation was delivered in four sessions with 12 hours intervals between sessions. The mean target volume was 3,851 mm(3) and the median cumulative marginal dose was 20 Gy. The median follow-up was 38.2 months. Visual acuity and visual fields were analyzed according to visual impairment score using the German Ophthalmological Society guidelines. RESULTS: Tumor control was achieved in 35 (94.6%) of the 37 patients with available follow-up images. Progressive tumor growth was observed in two craniopharyngioma patients (5.4%). Favorable visual outcomes in the postoperative period were achieved in 94.7% of cases (36/38). Sixteen patients showed visual function after fractionated GKRS, twenty cases were stationary, and two patients showed visual function deterioration after GKRS. CONCLUSION: GKRS is a safe and effective alternative to either surgery or fractionated radiotherapy for selected benign lesions that are adjacent to the optic apparatus.