Predictors of long-term tumor control after stereotactic radiosurgery for Koos grade 4 vestibular schwannomas.

PURPOSE: To evaluate the predictors of long-term tumor control following stereotactic radiosurgery (SRS) for Koos grade 4 vestibular schwannomas (VSs). METHODS: Overall, 203 sporadic VS patients with compression of the brainstem were treated with SRS. The median tumor volume was 6.7 cm3 (range, 2.0-28.9 cm3) and the median marginal dose was 12 Gy (range, 9-13.5 Gy). RESULTS: The median follow-up period was 152 months (range, 12-277 months). Tumor control (TC) rates at 3, 5, and 10 years were 89%, 85%, and 82%, respectively. Operation-free survival (OFS) rates at 3, 5, and 10 years were 92%, 85%, and 83%, respectively. Middle cerebellar peduncle (MCP) compression on pre-SRS magnetic resonance imaging scans was significant for both TC (p < 0.001, hazard ratio 1.332) and OFS (p < 0.001, hazard ratio 1.306). The 3-, 5-, and 10-year OFS rates were 98%, 94%, and 92% in the low-risk group (MCP compression < 9.8 mm and > 48 years old), and 58%, 25%, and 17% in high-risk group (MCP compression ≥ 9.8 mm and ≤ 48 years old), respectively. Ten patients (4.9%) developed delayed cyst-related complications. Eleven patients (5.4%) developed newly developed or worsened trigeminal neuralgia. No patient developed persistent facial palsy as an adverse radiation effect. A ventricular peritoneal shunt was required in six patients (3%) who developed hydrocephalus after SRS. CONCLUSION: SRS is an acceptable treatment option in selected patients with Koos grade 4 VSs. Risk group classification based on patient age and MCP compression is useful in decision-making of Koos grade 4 VSs.

Impact of breast cancer subtype on clinical outcomes after Gamma Knife radiosurgery for brain metastases from breast cancer: a multi-institutional retrospective study (JLGK1702).

INTRODUCTION: Brain metastasis (BM) is one of the most important issues in the management of breast cancer (BC), since BMs are associated with neurological deficits. However, the importance of BC subtypes remains unclear for BM treated with Gamma Knife radiosurgery (GKS). Thus, we conducted a multicenter retrospective study to compare clinical outcomes based on BC subtypes, with the aim of developing an optimal treatment strategy. METHODS: We studied 439 patients with breast cancer and 1-10 BM from 16 GKS facilities in Japan. Overall survival (OS) was analyzed by the Kaplan-Meier method, and cumulative incidences of systemic death (SD), neurologic death (ND), and tumor progression were estimated by competing risk analysis. RESULTS: OS differed among subtypes. The median OS time (months) after GKS was 10.4 in triple-negative (TN), 13.7 in Luminal, 31.4 in HER2, and 35.8 in Luminal-HER2 subtype BC (p < 0.0001). On multivariate analysis, poor control of the primary disease (hazard ratio [HR] = 1.84, p < 0.0001), active extracranial disease (HR = 2.76, p < 0.0001), neurological symptoms (HR 1.44, p = 0.01), and HER2 negativity (HR = 2.66, p < 0.0001) were significantly associated with worse OS. HER2 positivity was an independent risk factor for local recurrence (p = 0.03) but associated with lower rates of ND (p = 0.03). TN histology was associated with higher rates of distant brain failure (p = 0.03). CONCLUSIONS: HER2 positivity is related to the longer OS after SRS; however, we should pay attention to preventing recurrence in Luminal-HER2 patients. Also, TN patients require meticulous follow-up observation to detect distant metastases and/or LMD.

Salvage gamma knife radiosurgery for active brain metastases from small-cell lung cancer after whole-brain radiation therapy: a retrospective multi-institutional study (JLGK1701).

PURPOSE: To evaluate the efficacy of gamma knife radiosurgery (GKS) for brain metastases (BMs) from small-cell lung cancer after whole-brain radiotherapy (WBRT). METHODS: We retrospectively analyzed the usefulness and safety of GKS in 163 patients from 15 institutions with 1-10 active BMs after WBRT. The usefulness and safety of GKS were evaluated using statistical methods. RESULTS: The median age was 66 years, and 79.1% of patients were men. The median number and largest diameter of BM were 2.0 and 1.4 cm, respectively. WBRT was administered prophylactically in 46.6% of patients. The median overall survival (OS) was 9.3 months, and the neurologic mortality was 20.0%. Crude incidences of local control failure and new lesion appearance were 36.6% and 64.9%, respectively. A BM diameter ≥ 1.0 cm was a significant risk factor for local progression (hazard ratio [HR] 2.556, P = 0.039) and neurologic death (HR 4.940, P = 0.031). Leukoencephalopathy at the final follow-up was more prevalent in the therapeutic WBRT group than in the prophylactic group (P = 0.019). The symptom improvement rate was 61.3%, and neurological function was preserved for a median of 7.6 months. Therapeutic WBRT was not a significant risk factor for OS, neurological death, local control, or functional deterioration (P = 0.273, 0.490, 0.779, and 0.560, respectively). Symptomatic radiation-related adverse effects occurred in 7.4% of patients. CONCLUSIONS: GKS can safely preserve neurological function and prevent neurologic death in patients with 1-10 small, active BMs after prophylactic and therapeutic WBRT.

[A Case of Unilateral Multiple Cerebral Edema 4 Weeks after Coil Embolization].

Coil embolization for cerebral aneurysms can lead to various complications, such as aneurysm rupture and cerebral embolism. In recent years, foreign substance embolisms-caused by peeling off of coating materials from therapeutic devices-have been described. We report here a case of unilateral multiple cerebral edema four weeks after coil embolization. A 44-year-old woman presented with a subarachnoid hemorrhage from a right internal carotid-posterior communicating artery aneurysm, for which coil embolization was performed. Four weeks after the embolization, she developed numbness in the left side of her mouth and in her left upper extremity. Magnetic resonance images showed multiple edematous lesions in the right cerebral hemisphere. Subsequent treatment with steroids improved her symptoms and edematous cerebral lesions. Although definitive diagnosis by biopsy was not performed, her clinical course and imaging findings resembled a foreign substance embolism by hydrophilic coating. It is important to note that delayed cerebral edema due to foreign substance embolisms might occur after endovascular treatments.

Long-term hearing outcomes after gamma knife surgery in patients with vestibular schwannoma with hearing preservation: evaluation in 92 patients with serial audiograms.

The treatment strategy for patients with vestibular schwannoma (VS) is controversial, and data concerning the long-term hearing outcomes > 5 years after gamma knife surgery (GKS) are limited. The long-term hearing outcomes after GKS were evaluated in VS patients with hearing preservation. Ninety-two VS patients with a pure tone average (PTA) ≤ 50 dB were evaluated. The median age was 54 years; the median tumor volume was 1.5 cm3. The tumors were treated with a median margin dose of 12 Gy and a median mean cochlear dose of 4.0 Gy. At the time of GKS, 65 patients retained a PTA of 0-30 dB, and 27 had a PTA of 31-50 dB. The median follow-up period was 106 months. At the final follow-up, 2 (2%) developed tumor progression. During the median audiogram follow-up of 83 months, the PTA was ≤ 30 dB in 22 patients (24%) and 31-50 dB in 27 patients (29%); 43 patients (47%) worsened to a PTA > 50 dB. Hearing preservation rates were 66, 57, and 44% at 3, 5, and 10 years, respectively. In multivariate analysis, the mean cochlear dose (P < 0.001) and pre-GKS PTA (P = 0.045) were significant for hearing preservation. GKS was an effective treatment option for VS patients with a PTA ≤ 50 dB. As a lower cochlear dose and better pre-GKS PTA contributed to long-term hearing preservation, prophylactic GKS before hearing deterioration or tumor growth would be a treatment of choice if patients provided informed consent.

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.

[Meteorological Factors that Affect Stroke Onset].

BACKGROUND: To date, there have been many publications concerning relationship of meteorological condition and stroke onset. However, little is known about detailed meteorological factors that affect stroke onset. With hospital characteristics that most inpatients at our institution lived around Komaki, we examined the relationship between stroke onset and meteorological factors based on detailed meteorological data of Komaki. MATERIALS AND METHODS: Between April 1, 2012 and March 31, 2015, 1351 stroke patients admitted to Komaki City Hospital were enrolled in this study. These patients were classified into hypertensive intracranial hemorrhage(ICH), subarachnoid hemorrhage(SAH), and cerebral infarction(CI). Meteorological conditions such as season, weather, temperature, atmospheric pressure, and humidity were evaluated as factors that affect stroke onset. RESULTS: The incidence of ICH was lower in summer, and the minimum daily temperature was significantly related to ICH onset. The incidence of SAH was significantly related to the temperature difference compared to that on the previous day. When the mean temperature was lower than that on the previous day, the incidence of SAH was higher. No meteorological factor was found to affected the incidence of CI in this study. CONCLUSIONS: This study indicated that seasons and temperatures affect stroke onset.

Multisession gamma knife surgery for large brain metastases.

This study aimed to explore the safety and efficacy of multisession gamma knife surgery (GKS) for large brain metastases with a volume of 10 cm3 or larger. Fifty-six patients who had 65 brain metastases with a volume of at least 10 cm3 were treated with multisession GKS. Three-session GKS at a prescription dose of 10 Gy to the tumor margin per session with a 2-week interval between doses was performed in 3 patients. Other patients were treated with 2-session GKS at a prescription dose of 10-13 Gy to the tumor margin per session with an interval of 1-4 weeks. The median tumor volume was 21 cm3. The median survival was 7 months. The 6-, 12-, and 18-month survival rates were 62, 42, and 31%, respectively. The progression-free survival rates at 6, 12, and 18 months were 93, 80, and 74%, respectively. At the time of the first and last GKS sessions, the median tumor volumes were 21 and 15 cm3, respectively, which decreased to 5 cm3 with a median follow-up period of 6 months. Seventy-four percent of evaluated patients who had pre-GKS clinical symptoms obtained symptomatic improvement in a mean interval of 2 months. Multisession GKS was a safe and effective alternative to surgical resection for patients who had brain metastases with a tumor volume of 10 cm3 or larger. Although long-term results remain unclear, multisession GKS may be a suitable palliative treatment to preserve neurological function.

Efficacy of intraoperative irrigation with artificial cerebrospinal fluid in chronic subdural hematoma surgery: study protocol for a multicenter randomized controlled trial.

BACKGROUND: The surgical techniques for treatment of chronic subdural hematoma (CSDH), a common neurosurgical condition, have been discussed in a lot of clinical literature. However, the recurrence proportion after CSDH surgery remains high, ranging from 10 to 20%. The standard surgical procedure for CSDH involves a craniostomy to evacuate the hematoma, but irrigating the hematoma cavity during the procedure is debatable. The authors hypothesized that the choice of irrigation fluid might be a key factor affecting the outcomes of surgery. This multicenter randomized controlled trial aims to investigate whether intraoperative irrigation using artificial cerebrospinal fluid (ACF) followed by the placement of a subdural drain would yield superior results compared to the placement of a subdural drain alone for CSDH. METHODS: The study will be conducted across 19 neurosurgical departments in Japan. The 1186 eligible patients will be randomly allocated to two groups: irrigation using ACF or not. In either group, a subdural drain is to be placed for at least 12 h postoperatively. Similar to what was done in previous studies, we set the proportion of patients that meet the criteria for ipsilateral reoperation at 7% in the irrigation group and 12% in the non-irrigation group. The primary endpoint is the proportion of patients who meet the criteria for ipsilateral reoperation within 6 months of surgery (clinical worsening of symptoms and increased hematoma on imaging compared with the postoperative state). The secondary endpoints are the proportion of reoperations within 6 months, the proportion being stratified by preoperative hematoma architecture by computed tomography (CT) scan, neurological symptoms, patient condition, mortality at 6 months, complications associated with surgery, length of hospital stay from surgery to discharge, and time of the surgical procedure. DISCUSSION: We present the study protocol for a multicenter randomized controlled trial to investigate our hypothesis that intraoperative irrigation with ACF reduces the recurrence proportion after the removal of chronic subdural hematomas compared with no irrigation. TRIAL REGISTRATION: ClinicalTrials.gov jRCT1041220124. Registered on January 13, 2023.

Bevacizumab for refractory adverse radiation effects after stereotactic radiosurgery.

To retrospectively evaluate the clinical benefit and imaging response of bevacizumab when used to treat refractory adverse radiation effects (ARE) after stereotactic radiosurgery. Twenty-nine patients with brain tumors or vascular malformations developed clinical and/or imaging evidence of ARE after SRS and were treated using bevacizumab. Patients received an average dose of 7.4 mg/kg over a mean of 5.7 weeks at a median of 16 months following SRS. Initial diagnosis, SRS dose, bevacizumab treatment protocols, magnetic resonance imaging T2/FLAIR and T1 paramagnetic contrast enhanced edema volumes were compared before and after bevacizumab administration. Ninety percent (18/20) with clinically symptomatic ARE had neurological improvement after bevacizumab therapy. Twenty-six patients had a decrease of 62 % of T2/FLAIR volumes and a 50 % decrease in magnetic resonance imaging intravenous contrast enhancement volumes. Two patients showed progression of the T2/FLAIR and contrast enhancement volumes. One patient had progression of post-Gd-enhancement but regression of T2/FLAIR volume. Symptoms recurred in 11 of the 20 patients after discontinuing therapy. Patients who experienced a return of enhancement received a lower marginal dose during SRS. Our experience provides additional evidence that bevacizumab reduces both symptoms and reactive imaging changes in patients with ARE. After SRS, refractory ARE unresponsive to initial corticosteroids or other agents may benefit from a bevacizumab trial. The necessary duration and optimum dose of therapy is unknown and provides a further impetus to conduct a prospective trial.

Effect of embolization before stereotactic radiosurgery for brain arteriovenous malformations: a case-control study with propensity score matching.

OBJECTIVE: The aim of this study was to evaluate whether endovascular embolization prior to stereotactic radiosurgery (SRS) has a negative impact on nidus obliteration for patients with arteriovenous malformations (AVMs). METHODS: A total of 704 eligible patients with AVM who did not undergo prior surgery or radiotherapy were evaluated. Of these patients, 593 were treated with SRS only, and 111 were treated with embolization followed by SRS (E+SRS). Most patients in the E+SRS group (88%) underwent embolization with n-butyl-2-cyanoacrylate. In the comparison of radiosurgical outcomes between patients treated with SRS only and E+SRS, these groups were matched in a 1:1 ratio using propensity score matching to eliminate differences in basic characteristics. The primary outcome was to compare the nidus obliteration rates between the SRS-only and E+SRS groups. The secondary outcomes were the comparison of cumulative hemorrhage rates and the incidence of cyst formation or chronic encapsulated hematoma after SRS between these groups. RESULTS: In the unmatched cohorts, the actuarial 3-, 5-, and 8-year nidus obliteration rates after a single SRS session were 49.6%, 69.4%, and 74.1% in the SRS-only group, respectively, and 30.7%, 50.9%, and 68.6% in the E+SRS group, respectively (p = 0.001). In the matched cohort of 98 patients in each group, the rates were 47.1%, 62.0%, and 69.6% in the SRS-only group and 32.5%, 55.3%, and 75.0% in the E+SRS group, respectively (p = 0.24). There was no significant difference in either cumulative hemorrhage or the incidence of cyst formation or chronic encapsulated hematoma between the groups. CONCLUSIONS: Pre-SRS embolization did not affect nidus obliteration rates, cumulative hemorrhage rates, or the incidence of cyst formation or chronic encapsulated hematoma as late adverse radiation effects in patients with AVM treated with SRS.

Hemifacial spasm caused by multiple vascular attachments due to remote compression effects of a dermoid cyst in the cerebellar hemisphere: illustrative case.

BACKGROUND: Dermoid cysts located laterally in the posterior fossa are rare. The authors report the case of a dermoid cyst in the cerebellar hemisphere presenting with hemifacial spasm (HFS) caused by multiple vascular attachments due to remote compression effects. OBSERVATIONS: A 48-year-old man presented with left HFS. Computed tomography showed a mass lesion in the left cerebellar hemisphere with calcification and erosion of skull bone. Magnetic resonance imaging showed no contrast enhancement of the lesion and a dural defect. The lesion compressed the brainstem and cerebellopontine cistern, but no vascular attachments to the facial nerve were seen. Tumor removal and microvascular decompression were performed. The lesion was composed of soft tissue containing oil-like liquid and hairs, and the border of the cerebellar arachnoid was clear. There were multiple vascular attachments to the root exit zone, facial nerve, and brainstem. After displacing these arteries, the intraoperative abnormal muscle response disappeared. Histopathological findings showed stratified squamous epithelium, keratin flakes, calcifications, and hairs. The HFS disappeared completely and has remained absent for 27 months. LESSONS: The dermoid cyst originating from occipital bone compressed the cerebellar hemisphere, displacing multiple vessels and leading to HFS. Tumor removal and the removal of all vascular factors can completely resolve HFS.

Secondary aneurysmal bone cyst of the frontal bone with fibrous dysplasia showing rapid expansion: a case report.

A 19-year-old woman presented with swelling of the left forehead without pain. She did not have any relevant past or family history. Computed tomography showed destruction of the outer cortex of the frontal bone. A solitary mass lesion with a fluid collection was detected with magnetic resonance imaging. Because the swelling of the left forehead had enlarged rapidly with osteolytic changes, surgical removal of the lesion was performed. The lesion appeared to be enveloped in a fibrous capsule. The soft lesion was removed from the frontal bone. The outer frontal bone was absent, although the inner frontal bone was preserved. Then, the frontal bone was resected with margins from the edge of the erosion. The dura mater under the lesion was intact. A cranioplasty was performed using titanium mesh. On histological examination, the trabecular bones revealed irregular shapes and arrangements, indicating fibrous dysplasia. There was a continuous high-cell-concentration pathological lesion outside the fibrous dysplasia. There were numerous cells, such as mononuclear cells, osteoclast-like multinucleated giant cells, foam cells, and red blood cells. The osteoclast-like multinucleated giant cells and other cells did not show significant nuclear atypia. Immunostaining with H3.3G34W was negative, and the ubiquitin-specific peptidase 6/Tre-2 gene showed no rearrangements. The histopathological diagnosis was secondary aneurysmal bone cyst with fibrous dysplasia. Additional postsurgical therapy was not performed. There has been no evidence of recurrence of the lesion for two years.

Gamma Knife Radiosurgery for Metastatic Brain Tumors from Uterine Cervical and Endometrial Carcinomas: Histopathological Analysis of Survival and Local Control. A Japanese Multi-Institutional Cooperative and Retrospective Cohort Study.

OBJECTIVE: A retrospective comparative analysis of the outcomes of gamma knife radiosurgery (GKRS) for brain metastases from uterine cervical carcinoma (CC) and endometrial carcinoma (EC), investigated the efficacy and prognostic factors for survival and local tumor control. Histopathological analysis was also performed. METHODS: The authors retrospectively reviewed 61 patients with 260 tumors of CC and 73 patients with 302 tumors of EC who had undergone GKRS. RESULTS: The survival times after GKRS had no difference between CC and EC. Uncontrolled primary cancer was significant unfavorable factor. CC resulted in significantly higher neurological death and post-GKRS neurological deterioration. New lesions appeared intracranially after GKRS, with no significant difference between CC and EC. Local tumor control rates at 6, 12, and 24 months after GKRS were 90.0%, 86.6%, and 78.0% for CC and 92.2%, 87.9%, and 86.4% for EC. Primary cancer of CC, more than 7 cm3 volume, and prescription dose less than 20 Gy were significantly correlated in control failure. Local tumor control rates were significantly lower for squamous cell carcinoma in CC. No significant differences were found between histopathological subtypes of EC. CONCLUSIONS: This study established a relationship between the efficacy of GKRS for CC and EC brain metastases and the histopathological. Though, survival time after GKRS has no difference between CC and EC, CC was significantly higher neurogenic death and neurological deterioration after GKRS. Squamous cell carcinoma had a significantly lower rate of local tumor control among all CC, thereby resulting in CC having lower local tumor control than EC.

Efficacy of Magnetic Resonance Contrast-Enhanced Vessel Wall Imaging as an Ancillary Examination for Subarachnoid Hemorrhage With Bleeding Points Difficult to Determine on Conventional Vascular Imaging: A Report of Three Cases.

Here, we have demonstrated the efficacy of magnetic resonance contrast-enhanced vessel wall imaging (CE-VWI) as an ancillary examination for subarachnoid hemorrhage with bleeding points difficult to confirm by conventional vascular imaging. Case 1 had a ruptured small aneurysm with a size of 1.8 × 1.1 mm at the origin of left anterior choroidal artery. CE-VWI showed enhancement of the apex of the aneurysm. Surgical clipping was performed by a mini-clip. In Case 2, a ruptured small aneurysm, 2.1 × 1.9 mm, was detected at right middle cerebral artery bifurcation. CE-VWI showed enhancement of the aneurysmal wall. Endovascular coil embolization was performed. In Case 3, irregular dilatation of left internal carotid artery (ICA) was detected. CE-VWI demonstrated enhancement of the dilatation wall. The lesion was deemed to be a dissection of the ICA or a blood blister-like aneurysm. Endovascular treatment using intracranial stent placement was performed, and the patient has had no rebleeding events for one and a half years. In all cases, conventional vascular imaging detected scanty morphological changes, and CE-VWI information provided reliable confirmation of the lesions as bleeding points.

Intravascular Large B-Cell Lymphoma Diagnosed by Open Brain Biopsy and Achievement of Remission After Early Initiation of Chemotherapy: Case Report.

A 60-year-old man presented with progressive disturbance of consciousness. His father had died of malignant lymphoma, while his mother and sister died of acute leukemia. Magnetic resonance imaging (MRI) revealed multiple high-intensity lesions in the bilateral cerebral hemispheres on diffusion-weighted images. Serum soluble interleukin 2 receptor was 5,640 U/mL. Screenings of blood antibodies known to rise in autoimmune diseases were all normal. Cerebrospinal fluid examinations demonstrated slight elevation of protein and glucose, while the oligoclonal band and myelin basic protein were not elevated. Biopsies of bone marrow and random skin did not show any malignant features. His consciousness gradually deteriorated over a week, with lesions in his right frontal, left temporal, and bilateral parietal lobes shown to be growing. Therefore, open brain biopsy was performed, and one block of the right frontal lesion was harvested. Histological examination revealed atypical large cells only in the capillaries. Although immunohistochemical examinations showed positive staining for CD20, they were negative for CD3. Histopathological diagnosis was intravascular large B-cell lymphoma. After undergoing six cycles of intravenous chemotherapy with rituximab, cyclophosphamide, doxorubicin, and prednisone, his consciousness and neurological symptoms improved, and he appeared to achieve remission. Two years later, there have been no apparent recurrences, and the brain lesions have disappeared.

Long-Term Risks of Hemorrhage and Adverse Radiation Effects of Stereotactic Radiosurgery for Brain Arteriovenous Malformations.

BACKGROUND: The information about long-term risks of hemorrhage and late adverse radiation effects (AREs) after stereotactic radiosurgery for brain arteriovenous malformations (AVMs) is lacking. OBJECTIVE: To evaluate the long-term risks of hemorrhage and late ARE rates in patients with AVM treated with Gamma Knife surgery (GKS). METHODS: We examined 1249 patients with AVM treated with GKS. The Spetzler-Martin grade was I in 313 patients (25%), II in 394 (32%), III in 458 (37%), and IV/V in 84 (7%). The median treatment volume was 2.5 cm3, and the median marginal dose was 20 Gy. RESULTS: The median follow-up period was 61 months. The 5- and 10-year nidus obliteration rates were 63% and 82%, respectively. The 5- and 10-year cumulative hemorrhage rates were 7% and 10%, respectively. The annual hemorrhage rate was 1.5% for the first 5 years post-GKS, which decreased to 0.5% thereafter. During the follow-up period, 42 symptomatic cyst formations/chronic encapsulated hematomas ([CFs/CEHs], 3%) and 3 radiation-induced tumors (0.2%) were observed. The 10- and 15-year cumulative CF/CEH rates were 3.7% and 9.4%, respectively. CONCLUSION: GKS is associated with reduced hemorrhage risk and high nidus obliteration rates in patients with AVM. The incidence of late AREs tended to increase over time. The most common ARE was CF/CEH, which can be safely removed; however, careful attention should be paid to the long-term development of fatal radiation-induced tumors.

Intracranial Idiopathic Acute Epidural Hematoma Presenting with a Stroke-like Attack and Rapid Neurological Deterioration: A Case Report.

A 36-year-old woman presented with sudden onset of a right-sided headache that awoke her from sleep. She had no episodes of trauma or abuse. She was initially able to speak, but fell into a coma within an hour. The right pupil was dilated, with slow pupillary reflexes to light on both sides, and she showed left hemiparalysis. Computed tomography scan showed a right acute epidural hematoma, approximately 4 cm in thickness, and there were no findings of trauma such as skin wounds, subcutaneous hematomas, or skull fractures. In the emergency room, decompression of intracranial pressure by one burr hole was performed, and her dilated right pupil improved to normal size. She was then moved to the operating room, and hematoma removal was performed by craniotomy. Her blood pressure trended downward despite rapid blood transfusion and vasopressor therapy. There were no abnormal findings apparent intraoperatively, except for oozing from the whole surface of the dura mater and epidural space. Her consciousness improved postoperatively, and her left hemiparalysis improved within a few days. No causative diseases, risk factors, or vascular abnormalities were found on laboratory and radiological surveys. Two months postoperatively, the bone flap was removed because of infection. Eight months postoperatively, a cranioplasty using artificial skull was performed, and her postoperative course was uneventful. One year after the initial surgery, she has no neurological deficits, and there has been no recurrence of epidural hematoma.

Achieving good neurological outcome by combining decompressive craniectomy for acute subdural hematoma and transarterial embolization of intraperitoneal injured arteries for multiple severe trauma: a case report.

A 22-year-old woman jumped from the 4th floor of her apartment in an attempt to commit suicide. Whole-body computed tomography showed multiple injuries, including right acute subdural hematoma, left hemopneumothorax, several fractures, intraperitoneal hemorrhage, and spleen injury. Her consciousness deteriorated rapidly, and her right pupil was dilated. Furthermore, she had unstable vital signs including blood pressure of approximately 70/40 mmHg, pulse about 150/minute, respiratory rate 25/minute, and percutaneous oxygen saturation of 90% on 10 L oxygen. Intratracheal intubation and insertion of a thoracostomy tube were performed in the emergency room. Due to concomitant brain herniation and hemorrhagic shock, simultaneous decompressive craniectomy for acute subdural hematoma and transarterial embolization of intraperitoneal injured arteries were performed in our hybrid operating room. Despite rapid blood transfusions, the blood pressure did not increase. After starting embolization of the injured arteries of the spleen, the blood pressure increased, thereby making it possible to remove the acute subdural hematoma, and hemostasis was then achieved. Four hours later, the acute subdural hematoma and intracranial pressure increased again, and re-operation was performed in the normal operating room. Cranioplasty and clavicular fracture reduction were performed 14 days later. She recovered enough to talk and walk, and her consciousness stabilized. Interviews with her and her family by a psychiatrist determined that abnormal behaviors had first appeared 2 months earlier. She was diagnosed with acute and transient psychotic disorders, and treatment was started. The patient was discharged home 1 month later with mild disability of her higher-order brain function.

Primary Dural Mucosa-associated Lymphoid Tissue Lymphoma Mimicking Falx Meningioma: A Case Report.

An 85-year-old woman presented with ataxia and deterioration of cognitive functions. She had no history of autoimmune diseases or viral infections. Magnetic resonance imaging showed a solitary mass lesion at the cerebral falx on contrast-enhanced T1-weighted imaging. Gross total resection of the lesion involving the dura mater was performed by bifrontal craniotomy. Histological examination showed diffuse infiltration of small lymphocytes and plasma cells. There was also some proliferation of large lymphocytes with folded nuclei, high-density chromatin, and inconspicuous nucleoli. The large atypical B lymphocytes did not demonstrate diffuse dense sheet findings. Meningothelial components were not detected. Immunohistochemistry was positive for pan B-cell antigens. The analysis of the kappa/lambda ratio indicated kappa immunoglobulin light chain-restricted B-cell proliferation. The final histopathological diagnosis was mucosa-associated lymphoid tissue lymphoma. Systemic screening examinations were then performed. Histological findings of the bone marrow showed normal findings without atypical lymphocytes. A chromosomal study of the bone marrow showed 46, XX. 18F fluoro-2-deoxyglucose positron emission tomography showed high accumulations at the left pterygoid muscle and the right transverse processes of the thoracic vertebrae, and mild accumulation at the right ilium bone, which indicated disseminated lesions. One year later, thickening of the dura mater was detected. Therefore, gamma knife surgery was performed. Two years later, she was alive without neurological deterioration, and magnetic resonance imaging showed no evidence of recurrence.