Gamma Knife Thalamotomy for Essential Tremor: A Retrospective Analysis.

BACKGROUND: Gamma knife (GK) thalamotomy has been used as a treatment option for essential tremor (ET). Numerous studies on GK use in ET treatment have reported more varied responses and complication rates. METHODS: Data from 27 patients with ET who underwent GK thalamotomy were retrospectively analyzed. The Fahn-Tolosa-Marin Clinical Rating Scale for Tremor, handwriting, and spiral drawing were evaluated. Postoperative adverse events and magnetic resonance imaging findings were also evaluated. RESULTS: The mean age at GK thalamotomy was 78.1 ± 4.2 years. The mean follow-up period was 32.5 ± 19.4 months. The preoperative postural tremor, handwriting, and spiral drawing scores were 3.4 ± 0.6, 3.3 ± 1.0, and 3.2 ± 0.8, respectively, all of which showed significant improvements to 1.5 ± 1.2 (55.9% improvement, P < 0.001), 1.4 ± 1.1 (57.6% improvement, P < 0.001), and 1.6 ± 1.3 (50% improvement, P < 0.001), respectively, at the available final follow-up evaluations. Three patients presented with no improvement in tremor. Six patients presented with adverse effects, including complete hemiparesis, foot weakness, dysarthria, dysphagia, lip numbness, and finger numbness, at the final follow-up period. Two patients presented with serious complications, including complete hemiparesis due to massive widespread edema and chronic encapsulated expanding hematoma. One patient died of aspiration pneumonia following severe dysphagia secondary to chronic encapsulated expanding hematoma. CONCLUSIONS: GK thalamotomy is an efficient procedure for treating ET. Careful treatment planning is necessary to reduce complication rates. The prediction of radiation complications will increase the safety and effectiveness of GK treatment.

Efficacy of 3D evaluation of unruptured paraclinoid aneurysms within Leksell GammaPlan® for determination of their intradural localization.

BACKGROUND: Determination of the intradural unruptured paraclinoid aneurysm localization is difficult, but critical for selection of the optimal treatment strategy. OBJECTIVE: To assess efficacy of the three-dimensional (3D) evaluation of unruptured paraclinoid aneurysms within Leksell GammaPlan® (LGP; Elekta AB; Stockholm, Sweden) for determination of their intradural localization. METHODS: Overall, 125 incidentally diagnosed unruptured paraclinoid aneurysms in 118 patients (mean age, 55 years) underwent 3D evaluation of their localization within LGP using post-contrast thin-slice constructive interference in steady state (CISS) images, which in 41 cases were additionally co-registered and fused with the axial computed tomography angiography (CTA) source images. RESULTS: According to the evaluation within LGP, paraclinoid aneurysms were considered intradural, transitional, and extradural in 75, 25, and 25 cases respectively. Overall, 51 of 75 aneurysms deemed to be intradural, underwent microsurgical management, and intraoperative visual inspection confirmed their intradural localization in 45 cases, whereas it was transitional in 3, and extradural in 3. If during preoperative 3D evaluation within LGP only post-contrast CISS images were used, prediction of the pure intradural localization of aneurysm was correct in 88 % of cases (95 % CI: 79-97 %), and of the pure or partial (i.e., transitional) intradural localization in 94 % of cases (95 % CI: 88-100 %), whereas it was 100 % if co-registration and fusion of the contrast-enhanced CISS and CTA source images was done. CONCLUSION: Intradural localization of the unruptured paraclinoid aneurysms may be effectively predicted based on their 3D evaluation within LGP using post-contrast thin-slice CISS and CTA source images, which may help with clinical decision-making.

Mixed pial and dural arteriovenous fistula after craniotomy: case report and literature review.

Dural arteriovenous fistula (AVF) is known to occur after craniotomy, but mixed pial and dural AVF after craniotomy has not been reported. A 45-year-old man who had undergone surgical clipping of an unruptured aneurysm 2 years previously presented with small subcortical hemorrhage from mixed pial and dural AVF. Surgical disconnection could not be cured completely due to the granulomatous tissue around the aneurysm, and the presence of an undetected shunt. Postoperative digital subtraction angiography showed a new pial AVF supplied by the middle cerebral artery pial branches. Many branches were associated with the remnant aneurysm and pial AVF, so we did not try to embolize the fistula. Gamma knife surgery was performed as adjuvant radiotherapy, which achieved angiographically complete occlusion of the shunt points. Multimodal approaches including surgery, endovascular intervention, and radiotherapy are needed for radiological and clinical cure of mixed pial and dural AVF. Long-term follow up is essential.

Long-Term Results of Gamma Knife Radiosurgery for Trigeminal Neuralgia.

OBJECTIVE: Although the short- to medium-term efficacy of Gamma Knife therapy for drug-resistant essential trigeminal neuralgia has been reported, long-term evaluations are limited. We evaluated patient data obtained at least 10 years post-treatment and examined the significance of this treatment using new end points. METHODS: Among 249 consecutive patients with essential trigeminal neuralgia who were treated with Gamma Knife radiosurgery (retrogasserian target/4-mm single isocenter/90 Gy at 100%) at our institution between January 2003 and October 2011, 103 patients who were followed up for at least 10 years (mean, 174 [120-219] months) after treatment and whose data were amenable to accurate evaluation, were included in this retrospective study. Herein, we used the Barrow Neurological Institute (BNI) pain intensity scale as a clinical evaluation method for pain and the BNI numbness scale to evaluate complications (namely facial dysesthesia). RESULTS: The initial and final follow-up pain attack cessation (BNI pain intensity score I-IIIa) rate was 82.5% (85 of 103) and 58.2% (60 of 103), respectively. Furthermore, sensory impairment (BNI numbness score ≥ II) at the last follow-up was observed in 24.3% (25 of 103) of the cases, while very bothersome status (BNI numbness score IV) was observed in 2.9% of the cases. CONCLUSIONS: Gamma Knife radiosurgery for essential trigeminal neuralgia showed good therapeutic effects during long-term follow-up. Serious complications of significant concern in the short- to mid-term follow-up, resolved spontaneously. Therefore, the indications for treatment should be expanded to include patients who strongly desire Gamma Knife therapy.

Chronic Encapsulated Expanding Hematoma After Gamma Knife Thalamotomy for Essential Tremor.

There have been no previous reports of chronic encapsulated expanding hematoma after Gamma Knife thalamotomy. The present case underwent Gamma Knife thalamotomy for essential tremor at the age of 78 years. Three- and 12-month posttreatment magnetic resonance imaging (MRI) showed small T2 high-intensity lesions on the target and along with the internal capsule. Hemiparesis developed 17 months after the treatment. Twenty months post treatment, T2-MRI showed a hypointense mass across the target and internal capsule. Gradual expansion of the mass was confirmed on MRI at 26-38 months. A 54-month posttreatment MRI showed marked expansion of the mass with multiple cysts surrounded by a T2-hypointense rim. Gadolinium-enhanced T1-MRI showed partial enhancement of the mass. MRI findings suggested a radiation-induced cavernoma. Hemiparesis, dysesthesia, and pain on the right side of the body persisted even after steroid therapy for several months. Long-term careful observation is necessary after Gamma Knife thalamotomy.

Outcome After Resection of Craniopharyngiomas and the Important Role of Stereotactic Radiosurgery in Their Management.

OBJECTIVE: Experience with management of craniopharyngiomas (CPH) was evaluated retrospectively. METHODS: Between 1981 and 2012, 100 patients underwent removal of a CPH (the main surgical group), and an original tumor grading system was applied to these cases. The mean length of follow-up was 121 months. Additionally, 17 patients underwent removal of a CPH between 2012 and 2017 (the supplementary surgical group), and in 6 of them, CyberKnife radiosurgery was performed on a residual tumor (in 5 cases) or at the time of recurrence (in 1 case). RESULTS: In the main surgical group, the gross total resection (GTR) rate was 81%. The early and late disease-specific postoperative mortality rates were 0% and 2%, respectively. Tumor recurrence was never noted after GTR. There was a statistically significant increase in the Karnofsky Performance Scale (KPS) score after surgery. The tumor surgical grade was inversely associated with both the pre- and postoperative KPS scores, and was lower in cases operated on via the transnasal transsphenoidal approach, but was unrelated to the GTR rate. In the supplementary surgical group, the GTR rate was 65%. CyberKnife radiosurgery consistently resulted in tumor shrinkage. CONCLUSION: GTR is the preferred management option for CPH. The original surgical grading system developed at Tokyo Women's Medical University may be helpful for clinical decision-making. CyberKnife radiosurgery for residual and recurrent CPH is associated with high tumor response rates.

Gamma Knife Radiosurgery for Pituitary Adenomas Invading the Cavernous Sinus: Tokyo Women's Medical University Experience.

Total surgical removal of a pituitary adenoma (PA) invading the cavernous sinus (CS) is challenging and carries a significant risk of postoperative complications. As an alternative treatment strategy, after incomplete resection, such tumors may undergo stereotactic radiosurgery-in particular, Gamma Knife surgery (GKS). Treatment planning based on advanced neuroimaging (e.g., thin-slice 3-dimensional postcontrast constructive interference in steady state (CISS) images) allows clear visualization of the target microanatomy, which results in highly conformal and selective radiation delivery to the lesion with preservation of adjacent functionally important neurovascular structures. In the Tokyo Women's Medical University experience of GKS for 43 nonfunctioning and 46 hormone-secreting PA invading the CS, with a minimum follow-up period of 5 years (mean 76 months, range 60-118 months), the tumor control rate has reached 97%, and a significant volume reduction (≥50%) has been seen in 24% of lesions. In cases of hormone-secreting neoplasms, normalization (in 18 patients; 39%) or improvement (in 22 patients; 48%) of endocrinological function has been noted. Importantly, such effects have been sufficiently durable. Complications have been extremely rare and limited to transient cranial nerve palsy (in 2% of cases). Notably, no patient in our series has had a new pituitary hormone deficit after irradiation. Thus, subtotal resection followed by GKS may be considered a valuable alternative to aggressive surgery for a PA invading the CS.

Gamma Knife Radiosurgery for Symptomatic Cavernous Malformations: Tokyo Women's Medical University Experience.

OBJECTIVE: This retrospective study evaluated the results of Gamma Knife surgery (GKS) for symptomatic cavernous malformations (CM) of the brain. METHODS: From 1993 till 2014, 11 patients (mean age 44 years) with a symptomatic CM underwent GKS at Tokyo Women's Medical University. In six cases, the disease manifested with hemorrhaging. Seizures and a neurological deficit were noted in four patients each. The CM were located in the brainstem (in 5 cases), basal ganglia (in 2 cases), thalamus (in 2 cases), and cerebral lobe (in 2 cases). The mean lesion volume was 1.46 cc. The mean marginal dose was 15.3 Gy. The mean length of follow-up after GKS was 78.5 months. RESULTS: At the last follow-up, the general status was considered excellent, fair, and poor in 8 patients (73%), 1 patient (9%), and 2 patients (18%), respectively. The annual hemorrhage rates per case-year were 2.94% from birth till GKS, 20.20% from the first hemorrhage till GKS, 4.54% within the first 2 years after GKS, and 1.39% within the entire follow-up period after GKS. Two patients attained seizure-free status after treatment. CONCLUSION: GKS may be considered as a possible management option for symptomatic CM, since it reduces the subsequent hemorrhage risk after the initial bleeding episode. Moreover, in some patients, cessation of symptomatic epilepsy after treatment may be expected.

Pituitary Radiosurgery for Management of Intractable Pain: Tokyo Women's Medical University Experience and Literature Review.

Surgical or chemical hypophysectomy has historically shown good effectiveness in management of intractable pain but has often been accompanied by serious complications. In contrast, high-dose irradiation of the pituitary gland and stalk provides comparable analgesic effects and is associated with minimal morbidity. Although its physiological mechanism remains elusive, pituitary radiosurgery using the Gamma Knife has demonstrated high clinical efficacy and safety in cases of both cancer pain and noncancer pain. According to the available data, this treatment provides at least a temporary analgesic effect in >80% of patients, usually within hours to days after the procedure. Although the pain relief is most prominent and durable in cases of metastatic bone disease, it is not limited to that pathological condition or to cases of hormone-dependent cancers. Nevertheless, the low-quality studies reported to date cannot support any meaningful clinical recommendations on use of pituitary radiosurgery. Therefore, additional well-elaborated clinical and basic investigations, preferably performed in a multi-institutional and prospective fashion, are clearly needed and may bolster further developments of this highly promising treatment modality.

Results of surgical treatment after Gamma Knife radiosurgery for cerebral arteriovenous malformations: patient series.

BACKGROUND: Gamma Knife radiosurgery (GKRS) is a safe and effective treatment, but it has a risk of bleeding. Herein, the authors describe their experience with some patients who required surgical removal of cerebral arteriovenous malformations (AVMs) located mainly in eloquent areas of the brain after GKRS, and they consider the advantages of surgical removal after GKRS. OBSERVATIONS: Twelve patients who had undergone surgical removal of AVMs after GKRS at Tokyo Women's Medical University between April 2013 and July 2019 were selected for analysis. All participants underwent GKRS as first-line therapy for AVMs located in an eloquent region or if requested by the patient. Complete obliteration was achieved in 7 patients, and the size of the nidus decreased in 3 patients during the follow-up period. The Spetzler-Martin grade decreased in 11 patients. Three patients experienced symptomatic intracerebral hemorrhage before and after confirmation of complete obliteration of the nidus via GKRS, and 7 patients experienced some neurological deficits because of an encapsulated expanding hematoma. All patients underwent resection of the nidus without complications. The preoperative neurological deficits improved in 6 patients and remained unchanged in 6 patients. LESSONS: This report indicates that performing GKRS before surgery may be useful for future multimodal therapy.

A Case of Meningioma Originating from the Oculomotor Nerve.

BACKGROUND: Schwannoma originating from the oculomotor nerve has been reported. However, meningioma originating from this nerve was unknown. CASE DESCRIPTION: A 22-year-old woman presented with a unique case of meningioma originating from the oculomotor nerve manifesting as periorbital pain and diplopia beginning 4 months previously. Oculomotor nerve schwannoma was suggested by several pretreatment examinations. Tumor resection was considered risky for preservation of the oculomotor nerve function; therefore, gamma knife surgery (GKS) was performed. Six months later, she suffered right complete ptosis and worsened blurry vision. Corticosteroid was administered, but her symptoms did not improve. Magnetic resonance imaging showed the tumor lesion had grown larger. We decided to resect the tumor lesion because of her uncontrolled periorbital pain. The tumor had occupied the oculomotor cistern and was gross totally removed. Histologic diagnosis was surprisingly transitional meningioma. The tumor lesion occupied the oculomotor cistern and was refractory to GKS, with a progressive clinical course, which is more suggestive of meningioma than schwannoma, although extremely rare. Her periorbital pain and blurry vision gradually regressed, whereas complete oculomotor nerve palsy persisted. CONCLUSIONS: In such a case, tumor resection after GKS should be considered.

Gamma Knife Surgery for Residual or Recurrent Craniopharyngioma After Surgical Resection: A Multi-institutional Retrospective Study in Japan.

Objective The optimal treatment for a craniopharyngioma has been controversial. Complete resection is ideal, but it has been difficult to obtain total resection in many cases because of intimate proximity to critical structures such as the optic pathway, hypothalamus, and pituitary gland. A growing number of studies have demonstrated the utility of radiosurgery in controlling residual or recurrent craniopharyngioma. However, most of them are small series. The aim of this multi-institutional study was to clarify the efficacy and safety of Gamma Knife (Elekta, Stockholm, Sweden) surgery for patients with a craniopharyngioma. Methods This was a multi-institutional retrospective study by 16 medical centers of the Japan Leksell Gamma Knife Society. Data on patients with craniopharyngiomas treated with Gamma Knife Surgery (GKS) between 1991 and 2013 were obtained from individual institutional review board-approved databases at each center. A total of 242 patients with craniopharyngioma were included in this study. The mean age of the patients was 41 (range, 3 to 86) years. The median follow-up time was 61.4 months (range, 3 to 180 months). The mean radiosurgery target volume was 3.1 ml (range, 0.03-22.3 ml), and the mean marginal dose was 11.4 Gy (range, 8-20.4 Gy). Results Two-hundred twenty patients were alive at the time of the last follow-up visit. The three-, five-, and 10-year overall survival rates after GKS were 95.4%, 92.5%, and 82.0%, respectively. The three-, five-, and 10-year progression-free survival rates after GKS were 73.1%, 62.2%, and 42.6% respectively. The rate of radiation-induced complications was 6.2%. Conclusion GKS is effective for controlling the tumor growth of craniopharyngiomas with an acceptable complication rate.

Can pediatric Gamma Knife radiosurgery be managed under monitored anesthesia care? A case presentation and proposal from anesthesiologists.

Gamma Knife radiosurgery is generally performed under procedural sedation and analgesia. However, there are some risks regarding the patient's respiratory function and the specifics of its management, since the presence of a stereotactic frame may impede access to the patient's airway and interfere with direct visual observation by medical personnel. Monitored anesthesia care, which is a specific anesthesia service for diagnostic or therapeutic procedures that involve various levels of sedation, analgesia and anxiolysis, is recognized as producing less physiologic disturbance while allowing a more rapid recovery than general anesthesia. The selection of suitable candidates and medications, as well as the early detection of respiratory deterioration are considered to be essential for patient safety.

Gamma Knife Radiosurgery for Metastatic Brain Tumors from Malignant Melanomas: A Japanese Multi-Institutional Cooperative and Retrospective Cohort Study (JLGK1501).

BACKGROUND: The incidences of metastatic brain tumors from malignant melanomas have increased and survival has been prolonged by novel molecular targeted agents and immunotherapy. However, malignant melanomas are uncommon in Asian populations. OBJECTIVES: We retrospectively analyzed treatment efficacy and identified prognostic factors impacting tumor control and survival in Japanese melanoma patients with brain metastases treated with gamma knife radiosurgery (GKRS). METHODS: We retrospectively reviewed the medical records of 177 patients with 1,500 tumors who underwent GKRS for brain metastases from malignant melanomas. This study was conducted by the Japanese Leksell Gamma Knife Society (JLGK1501). RESULTS: Six and 12 months after GKRS, the cumulative incidences of local tumor recurrence were 9.2 and 13.8%. Intratumoral hemorrhage (p < 0.0001) and larger tumor volume (p = 0.001) in GKRS were associated with significantly poorer local control outcomes. The use of immune checkpoint inhibitors before GKRS was significantly associated with symptomatic adverse events (p = 0.037). The median overall survival time after the initial GKRS was 7.3 months. Lower Karnofsky performance status scores (p = 0.016), uncontrolled primary cancer (p < 0.0001), and multiple brain metastases (p = 0.014) significantly influenced unfavorable overall survival outcomes. The cumulative incidences of neurological death 6 and 12 months after GKRS were 9.7 and 17.4%, those of neurological deterioration were 14.2 and 19.6%, and those of new tumor appearance were 34.5 and 40.5%. CONCLUSIONS: The results of the present multicenter study suggest that GKRS is a relatively effective and safe modality for control of tumor progression in Japanese patients with brain metastases from malignant melanomas.

Gamma Knife treatment of malignant infantile brain tumors - Case report.

Stereotactic radiosurgery (SRS) is a treatment option, which is capable of pinpoint irradiation and thus, reduce the potential late complications. However, any type of radiation therapy is not recommended for brain tumor patients under the age of 3 years. SRS is not routinely recommended for patients than 2 years of age in consideration of infant skull brittleness for frame fixation, and lack of treatment evidence for the safety and effects of stereotactic radiosurgery in infants. We experienced the case of Gamma Knife treatment upon an infantile pineoblastoma where repeated tumor excision had already been perfromed and chemotherapy resistance was apparent. Radiosurgery resulted in symptom improvement and dramatic tumor shrinkage on MRI after radiosurgery. Therefore, here we report on the difficulty and usefulness of Gammaknife radiosurgery in this infant patient.

Effects of Surgery With Salvage Stereotactic Radiosurgery Versus Surgery With Whole-Brain Radiation Therapy in Patients With One to Four Brain Metastases (JCOG0504): A Phase III, Noninferiority, Randomized Controlled Trial.

Purpose Whereas whole-brain radiotherapy (WBRT) has been the standard treatment of brain metastases (BMs), stereotactic radiosurgery (SRS) is increasingly preferred to avoid cognitive dysfunction; however, it has not been clearly determined whether treatment with SRS is as effective as that with WBRT or WBRT plus SRS. We thus assessed the noninferiority of salvage SRS to WBRT in patients with BMs. Patients and Methods Patients age 20 to 79 years old with performance status scores of 0 to 2-and 3 if caused only by neurologic deficits-and with four or fewer surgically resected BMs with only one lesion > 3 cm in diameter were eligible. Patients were randomly assigned to WBRT or salvage SRS arms within 21 days of surgery. The primary end point was overall survival. A one-sided α of .05 was used. Results Between January 2006 and May 2014, 137 and 134 patients were enrolled in the WBRT and salvage SRS arms, respectively. Median overall survival was 15.6 months in both arms (hazard ratio, 1.05; 90% CI, 0.83 to 1.33; one-sided P for noninferiority = .027). Median intracranial progression-free survival of patients in the WBRT arm (10.4 months) was longer than that of patients in the salvage SRS arm (4.0 months). The proportions of patients whose Mini-Mental Status Examination and performance status scores that did not worsen at 12 months were similar in both arms; however, 16.4% of patients in the WBRT arm experienced grade 2 to 4 cognitive dysfunction after 91 days postenrollment, whereas only 7.7% of those in the SRS arm did ( P = .048). Conclusion Salvage SRS is noninferior to WBRT and can be established as a standard therapy for patients with four or fewer BMs.

Development of a Preoperative Simulation Technique for Carotid Endarterectomy in Patients with Contrast Contraindications.

BACKGROUND: Vascular and osteological parameters, such as the heights of the carotid bifurcation and distal end of the plaque, are important preoperative considerations for patients undergoing carotid stenosis procedures, such as carotid endarterectomy. However, for patients with contraindications to contrast media, such as allergies or nephropathies, 3-dimensional computed tomography angiography (3D-CTA) is unavailable, and preoperative evaluation remains challenging. In the present study, we aimed to develop a preoperative simulation for use in patients with contrast-contraindicated carotid stenosis. METHODS: Images from noncontrast neck computed tomography scans and magnetic resonance imaging obtained without the Leksell stereotactic frame were uploaded to GammaPlan. Following delineation of various structures, preoperative simulations were performed to determine the relationships between vascular and osteological structures. We applied this technique in 10 patients with carotid stenosis to verify the accuracy of the simulation. RESULTS: In all patients, the GammaPlan simulation successfully visualized the heights of the carotid bifurcation and distal end of the plaque without the use of contrast medium. Furthermore, information regarding the location of internal arterial structures, such as calcifications and unstable plaques, could be incorporated into GammaPlan images. We verified simulation accuracy by comparing the simulation results with 3D-CTA and operative findings. CONCLUSIONS: Simulations created using GammaPlan can be used to obtain accurate vascular and osteological information regarding the heights of the carotid bifurcation and distal end of the plaque, without the use of contrast medium. The reconstruction of delineated structures using this technique may be effective for preoperative evaluation in patients with contrast-contraindicated carotid stenosis.