Successful surgical treatment of oculomotor palsy due to schwannoma of the cavernous sinus in a 7-year-old girl: a case report.

Oculomotor nerve schwannoma in children not associated with neurofibromatosis is a rare disease, with 26 pediatric cases reported so far. There is no established treatment plan. A 7-year-old girl presented with oculomotor nerve palsy. Surgical reduction of the tumor combined with postoperative gamma knife surgery preserved the oculomotor nerve, improved oculomotor nerve function, and achieved tumor control during the observation period of 20 months. The combination of partial surgical resection and gamma knife surgery as a treatment strategy for oculomotor nerve schwannoma resulted in a good outcome.

Preplanned Partial Surgical Removal Followed by Low-Dose Gamma Knife Radiosurgery for Large Vestibular Schwannomas.

OBJECTIVE: The present study evaluated outcomes after preplanned partial surgical removal of a large vestibular schwannoma (VS) followed by low-dose Gamma Knife surgery (GKS). METHODS: Between January 2000 and May 2015, 47 patients with a unilateral VS (median maximum diameter 32 mm) underwent preplanned partial tumor removal at our clinic. GKS for a residual lesion was done within a median time interval of 3 months. The median prescription dose was 12 Gy. The median length of subsequent follow-up was 74 months. RESULTS: The actuarial tumor growth control rates without a need for additional management at 3, 5, and 15 years after GKS were 92%, 86%, and 86%, respectively. At the time of the last follow-up, the function of the ipsilateral facial nerve corresponded to House-Brackmann grade I in 92% of patients. Significant improvement of ipsilateral hearing was noted in two patients after partial tumor removal and in one after GKS. Among 16 patients who presented with ipsilateral serviceable hearing, it was preserved immediately after surgery in 81% of cases and at the time of the last follow-up in 44%. Salvage surgical treatment was required in 9% of patients. CONCLUSION: Preplanned partial surgical removal followed by low-dose GKS provides a high level of functional preservation in patients with a large VS.

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.

Stereotactic radiosurgery in elderly patients with brain metastases: comparison with non-elderly patients using database of a multi-institutional prospective observational study (JLGK0901-Elderly).

PURPOSE: Stereotactic radiosurgery (SRS) has been increasingly used for elderly patients with brain metastases (BMs). However, no studies based on a large sample size have been reported. To compare SRS treatment results between elderly and non-elderly patients, we performed a subset study of elderly patients using our prospectively-accumulated multi-institution study database (JLGK0901 Study, Lancet Oncol 15:387-395, 2014). METHODS: During the 2009-2011 period, 1194 eligible patients undergoing gamma knife SRS alone for newly diagnosed BMs were enrolled in this study from 23 gamma knife facilities in Japan. Observation was discontinued at the end of 2013. The 1194 patients were divided into the two age groups, 693 elderly ( ≥ 65 years) and 501 non-elderly ( < 65 years) patients. Our study protocol neither set an upper age limit nor required dose de-escalation. RESULTS: Median post-SRS survival time was significantly shorter in the elderly than in the non-elderly patient group (10.3 vs 14.3 months, HR 1.380, 95% CI 1.218-1.563, p < 0.0001). However, regarding all secondary endpoints including neurological death, neurological deterioration, SRS-related complications, leukoencephalopathy, local recurrence, newly-developed tumors, meningeal dissemination, salvage SRS, whole brain radiotherapy and surgery and decreased mini-mental state examination scores, the elderly patient group was not inferior to the non-elderly patient group. In the 693 elderly patients, there was no post-SRS median survival time difference between those with 5-10 versus 2-4 tumors (10.8 vs 8.9 months, HR 0.936, 95% CI 0.744-1.167, p = 0.5601). CONCLUSIONS: We conclude that elderly BM patients are not unfavorable candidates for SRS alone treatment.

Effects of C-reactive protein on the expression of matrix metalloproteinases and their inhibitors via Fcγ receptors on 3T3-L1 adipocytes.

The association between obesity and inflammation is well documented in epidemiological studies. Proteolysis of extracellular matrix (ECM) proteins is involved in adipose tissue enlargement, and matrix metalloproteinases (MMPs) collectively cleave all ECM proteins. Here, we examined the effects of C-reactive protein (CRP), an inflammatory biomarker, on the expression of MMPs and tissue inhibitors of metalloproteinases (TIMPs), which are natural inhibitors of MMPs, in adipocyte-differentiated 3T3-L1 cells. We analyzed the expression of Fcγ receptor (FcγR) IIb and FcγRIII, which are candidates for CRP receptors, and the effects of anti-CD16/CD32 antibodies, which can act as FcγRII and FcγRIII blockers on CRP-induced alteration of MMP and TIMP expression. Moreover, we examined the effects of CRP on the activation of mitogen-activated protein kinase (MAPK) signaling, which is involved in MMP and TIMP expression, in the presence or absence of anti-CD16/CD32 antibodies. Stimulation with CRP increased MMP-1, MMP-3, MMP-9, MMP-11, MMP-14, and TIMP-1 expression but did not affect MMP-2, TIMP-2, and TIMP-4 expression; TIMP-3 expression was not detected. Adipocyte-differentiated 3T3-L1cells expressed FcγRIIb and FcγRIII; this expression was upregulated on stimulation with CRP. Anti-CD16/CD32 antibodies inhibited CRP-induced expression of MMPs, except MMP-11, and TIMP-1. CRP induced the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and p38 MAPK but did not affect SAPK/JNK phosphorylation, and Anti-CD16/CD32 attenuated the CRP-induced phosphorylation of p38 MAPK, but not that of ERK1/2. These results suggest that CRP facilitates ECM turnover in adipose tissue by increasing the production of multiple MMPs and TIMP-1 in adipocytes. Moreover, FcγRIIb and FcγRIII are involved in the CRP-induced expression of MMPs and TIMP-1 and the CRP-induced phosphorylation of p38, whereas the FcγR-independent pathway may regulate the CRP-induced MMP-11 expression and the CRP-induced ERK1/2 phosphorylation.

Frequency Ratio of (199)Hg and (87)Sr Optical Lattice Clocks beyond the SI Limit.

We report on a frequency ratio measurement of a (199)Hg-based optical lattice clock referencing a (87)Sr-based clock. Evaluations of lattice light shift, including atomic-motion-dependent shift, enable us to achieve a total systematic uncertainty of 7.2×10(-17) for the Hg clock. The frequency ratio is measured to be νHg/νSr=2.629 314 209 898 909 60(22) with a fractional uncertainty of 8.4×10(-17), which is smaller than the uncertainty of the realization of the International System of Units (SI) second, i.e., the SI limit.

Stereotactic radiosurgery for patients with multiple brain metastases (JLGK0901): a multi-institutional prospective observational study.

BACKGROUND: We aimed to examine whether stereotactic radiosurgery without whole-brain radiotherapy (WBRT) as the initial treatment for patients with five to ten brain metastases is non-inferior to that for patients with two to four brain metastases in terms of overall survival. METHODS: This prospective observational study enrolled patients with one to ten newly diagnosed brain metastases (largest tumour <10 mL in volume and <3 cm in longest diameter; total cumulative volume ≤15 mL) and a Karnofsky performance status score of 70 or higher from 23 facilities in Japan. Standard stereotactic radiosurgery procedures were used in all patients; tumour volumes smaller than 4 mL were irradiated with 22 Gy at the lesion periphery and those that were 4-10 mL with 20 Gy. The primary endpoint was overall survival, for which the non-inferiority margin for the comparison of outcomes in patients with two to four brain metastases with those of patients with five to ten brain metastases was set as the value of the upper 95% CI for a hazard ratio (HR) of 1·30, and all data were analysed by intention to treat. The study was finalised on Dec 31, 2012, for analysis of the primary endpoint; however, monitoring of stereotactic radiosurgery-induced complications and neurocognitive function assessment will continue for the censored subset until the end of 2014. This study is registered with the University Medical Information Network Clinical Trial Registry, number 000001812. FINDINGS: We enrolled 1194 eligible patients between March 1, 2009, and Feb 15, 2012. Median overall survival after stereotactic radiosurgery was 13·9 months [95% CI 12·0-15·6] in the 455 patients with one tumour, 10·8 months [9·4-12·4] in the 531 patients with two to four tumours, and 10·8 months [9·1-12·7] in the 208 patients with five to ten tumours. Overall survival did not differ between the patients with two to four tumours and those with five to ten (HR 0·97, 95% CI 0·81-1·18 [less than non-inferiority margin], p=0·78; pnon-inferiority<0·0001). Stereotactic radiosurgery-induced adverse events occurred in 101 (8%) patients; nine (2%) patients with one tumour had one or more grade 3-4 event compared with 13 (2%) patients with two to four tumours and six (3%) patients with five to ten tumours. The proportion of patients who had one or more treatment-related adverse event of any grade did not differ significantly between the two groups of patients with multiple tumours (50 [9%] patients with two to four tumours vs 18 [9%] with five to ten; p=0·89). Four patients died, mainly of complications relating to stereotactic radiosurgery (two with one tumour and one each in the other two groups). INTERPRETATION: Our results suggest that stereotactic radiosurgery without WBRT in patients with five to ten brain metastases is non-inferior to that in patients with two to four brain metastases. Considering the minimal invasiveness of stereotactic radiosurgery and the fewer side-effects than with WBRT, stereotactic radiosurgery might be a suitable alternative for patients with up to ten brain metastases. FUNDING: Japan Brain Foundation.

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.

[Spontaneous cerebrospinal fluid rhinorrhea associated with long-standing overt ventriculomegaly in adults (LOVA)].

OBJECTIVE: Spontaneous cerebrospinal fluid rhinorrhea associated with aqueductal stenosis is rare. CSF diversion is reported to be a failure in the majority of cases. The combination of the repair of the skull base and CSF diversion is reported to be successful. We describe a case successfully treated by intradural repair with ventricular drainage followed by endoscopic third ventriculostomy. CLINICAL PRESENTATION: A 28-year-old woman presented with rhinorrhea, and occasional attacks of headache, vomiting, and unconsciousness for two years. She had been diagnosed as arrested hydrocephalus for 10 years. Magnetic resonance imaging revealed triventriculomegaly with ballooning of the floor of the third ventricle, tonsilar herniation, right anterior horn herniation into the cribriform plate, and bilateral temporal lobe herniation into the temporal base. INTERVENTION: A ventricular drain was inserted followed by dissection of the herniated brain and repair of the enlarged cribriform foramen with periosteal flap. Make sure that the bacterial culture negative, endoscopic third ventriculostomy has been performed. There is no recurrence of hydrocephalus and rhinorrhea for two years. CONCLUSION: Direct communication between the lateral ventricle and the nasal/paranasal sinus is a rare complication of aqueductal stenosis and LOVA. Surgical repair of the skull base followed by cerebrospinal fluid diversion with endoscopic third ventriculostomy was a safe and reliable method.

Outcomes of Gamma Knife radiosurgery for skull base chondrosarcomas: a multi-institutional retrospective study.

OBJECTIVE: Radiotherapy has an essential role in the management of skull base chondrosarcomas (SBCs) after resection. This multi-institutional study evaluated the outcomes of Gamma Knife radiosurgery (GKRS) for histopathologically proven SBCs. METHODS: Data of patients who underwent GKRS for SBCs at Gamma Knife centers in Japan were retrospectively collected. Patients without a histopathological diagnosis and those who had intracranial metastases from extracranial chondrosarcomas were excluded. Histologically, grade III and some nonconventional variants were identified as aggressive types. The cumulative local control rates (LCRs) and disease-specific survival (DSS) rates were calculated using the Kaplan-Meier method. Factors potentially affecting the LCR were evaluated using the Cox proportional hazards model for bivariate and multivariate analyses. The incidence of radiation-induced adverse effects (RAEs) was calculated as crude rates, and factors associated with RAEs were examined using Fisher's exact test. RESULTS: Fifty-one patients were enrolled, with a median age of 38 years. Thirty patients (59%) were treated with upfront GKRS for residual SBCs after resection (n = 27) or biopsy (n = 3), and 21 (41%) underwent GKRS as a salvage treatment for recurrence. The median tumor volume was 8 cm3. The overall LCRs were 87% at 3 years, 78% at 5 years, and 67% at 10 years after GKRS. A better LCR was associated with a higher prescription dose (p = 0.039) and no history of repeated recurrence before GKRS (p = 0.024). The LCRs among patients with the nonaggressive histological type and treatment with ≥ 16 Gy were 88% at 3 years, 83% at 5 years, and 83% at 10 years. The overall survival rates after GKRS were 96% at 5 years and 83% at 10 years. Although RAEs were observed in 3 patients (6%), no severe RAEs with Common Terminology Criteria for Adverse Events grade 3 or higher were identified. No significant factor was associated with RAEs. CONCLUSIONS: GKRS for SBCs has a favorably low risk of RAEs and could be a reasonable therapeutic option for SBC in multimodality management. A sufficient GKRS prescription dose is necessary for higher LCRs. Histological grading and subtype evaluations are important for excluding exceptional SBCs. Patients with conventional SBCs have a long life expectancy and should be observed for life after treatment.

A Practical Grading Scale for Predicting Outcomes of Radiosurgery for Dural Arteriovenous Fistulas: JLGK 1802 Study.

BACKGROUND AND PURPOSE: To assess the long-term outcomes of intracranial dural arteriovenous fistula (DAVF) treated with stereotactic radiosurgery (SRS) alone or embolization and SRS (Emb-SRS) and to develop a grading system for predicting DAVF obliteration. METHODS: This multi-institutional retrospective study included 200 patients with DAVF treated with SRS or Emb-SRS. We investigated the long-term obliteration rate and obliteration-associated factors. We developed a new grading system to estimate the obliteration rate. Additionally, we compared the outcomes of SRS and Emb-SRS by using propensity score matching. RESULTS: The 3- and 4-year obliteration rates were 66.3% and 78.8%, respectively. The post-SRS hemorrhage rate was 2%. In the matched cohort, the SRS and Emb-SRS groups did not differ in the rates of obliteration (P=0.54) or post-SRS hemorrhage (P=0.50). In multivariable analysis, DAVF location and cortical venous reflux (CVR) were independently associated with obliteration. The new grading system assigned 2, 1, and 0 points to DAVFs in the anterior skull base or middle fossa, DAVFs with CVR or DAVFs in the superior sagittal sinus or tentorium, and DAVFs without these factors, respectively. Using the total points, patients were stratified into the highest (0 points), intermediate (1 point), or lowest (≥2 points) obliteration rate groups that exhibited 4-year obliteration rates of 94.4%, 71.3%, and 60.4%, respectively (P<0.01). CONCLUSIONS: SRS-based therapy achieved DAVF obliteration in more than three-quarters of the patients at 4 years of age. Our grading system can stratify the obliteration rate and may guide physicians in treatment selection.

[Transsphenoidal surgery for pituitary tumors from microsurgery to the endoscopic surgery: single surgeon's experience].

We reviewed results of the surgical outcome of pituitary tumors treated via the transsphenoidal approach between January, 1994 and January, 2010 at our institution. This data included 100 patients (124 procedures) treated through the sublabial transsphenoidal approach and 45 patients (54 procedures) treated through the endoscopic endonasal (bilateral nostrils) transsphenoidal approach performed by a single surgeon. The extent of tumor removal was significantly improved with endoscopic surgery; adjuvant gamma knife radiosurgery was needed for 65% of patients undergoing microsurgery vs. 30% for patients who had endoscopic surgery (p<0.0001). Patients who underwent endoscopic surgery had less intraoperative blood loss (mean volume: 100 mL for microsurgery patients vs. 30 mL for endoscopic surgery patients, p<0.0001), less pain, and less need for postoperative hormone replacement therapy (19% for microsurgery patients vs. 6% for endoscopic surgery patients; p<0.05). CSF leakage and meningitis were experienced in one microsurgery patient (1%) and one endoscopic surgery patient (2.2%). Endoscopic surgery is a reasonable alternative to microsurgery and our experience supports the concept that an otolaryngologist/neurosurgeon team skilled in endoscopic techniques and pituitary surgery can safely make the transition from microsurgery to endoscopic surgery.

Gamma Knife Radiosurgery for Concurrent Trigeminal Neuralgia and Glossopharyngeal Neuralgia.

An 82-year-old female had suffered right facial pain since 37 years of her age. The trigeminal neuralgia (TN) was controlled by carbamazepine and peripheral nerve block. The local block was effective for two to three years once performed, and as it became less effective, the patient took carbamazepine. Four months before gamma knife radiosurgery (GKRS), TN worsened. Analysis of her blood sample revealed autoimmune hemolytic anemia. It was suspected to be related to carbamazepine, and the patient stopped taking carbamazepine. The patient suffered pharyngeal pain and had difficulty swallowing for two months before GKRS. Tube feeding was started one month before GKRS. The patient was considered in pain due to TN and glossopharyngeal neuralgia (GPN). We performed GKRS continuously on the right cisternal portion of the trigeminal nerve at a maximum radiosurgical dose of 85 Gy for TN, and on the right cisternal portion of the glossopharyngeal nerve at a maximum dose of 80 Gy for GPN on the same day. The facial pain improved the day after GKRS. Seven days after treatment, the patient could swallow without pharyngeal pain, and the gastric tube was removed. Thirteen months after GKRS, the TN re-occurred but was controlled by carbamazepine 400 mg per day. GPN did not recur at that time. Simultaneous GKRS for concurrent TN and GPN is a less invasive and useful treatment option for non-candidates for surgical interventions.

A single nucleotide polymorphism in the FADS1/FADS2 gene is associated with plasma lipid profiles in two genetically similar Asian ethnic groups with distinctive differences in lifestyle.

Recent genome-wide association studies (GWASs) showed that single nucleotide polymorphisms (SNPs) in FADS1/FADS2 were associated with plasma lipid concentrations in populations with European ancestry. We investigated the associations between the SNPs in FADS1/FADS2 and plasma concentrations of triglycerides, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in two Asian groups, i.e., Japanese and Mongolians. The genotype of rs174547 (T/C), found to be associated with triglyceride and HDL-C concentrations in the GWAS, was determined in 21,004 Japanese and 1,203 Mongolian individuals. Genotype-phenotype association was assessed by using multiple linear regression models, assuming an additive model of inheritance. The copy number of the rs174547 C allele was significantly associated with increased triglyceride levels (P = 1.5 x 10(-6)) and decreased HDL-C levels (P = 0.03) in the Japanese population. On the other hand, in the Mongolian population, the rs174547 C allele copy number was strongly associated with decreased LDL-C levels (P = 2.6 x 10(-6)), but was not associated with triglyceride and HDL-C levels. The linkage disequilibrium pattern and haplotype structures of SNPs around the FADS1/FADS2 locus showed no marked dissimilarity between Japanese and Mongolian individuals. The present data indicate that the FADS1/FADS2 locus can be added to the growing list of loci involved in polygenic dyslipidemia in Asians. Furthermore, the variable effects of FADS1/FADS2 on plasma lipid profiles in Asians may result from differences in the dietary intake of polyunsaturated fatty acids, which serve as substrates for enzymes encoded by FADS1/FADS2.

[Experience in the treatment for intracranial arteriovenous shunts in children].

PURPOSE: To report our experiences in the treatment for intracranial arteriovenous shunts (AV shunts) in the pediatric population. MATERIAL AND METHODS: Twelve children with intracranial AV shunts were treated with endovascular embolization between December 1993 and March 2008. These comprised two cases of vein of Galen aneurysmal malformation, three of dural sinus malformation, two of infantile dural AV shunt, five of pial AV fistula including two of vein of Galen aneurysmal dilatation. There were eleven boys and one girl. The age at the first embolization ranged from day 0 to 9 years. We reviewed their clinical features and outcomes. RESULTS: Six patients including four neonates presented with congestive heart failure, one infant with macrocrania and three children with headache, seizure or ataxia. The number of endovascular embolization ranged from one to five per patient. These included eighteen transarterial embolizations and ten transvenous embolizations. All patients except for one who died eventually from pulmonary hemorrhage showed improvement in their symptoms. Although only five patients achieved complete occlusion of AV shunts, six patients including them developed normally. CONCLUSION: Intracranial AV shunts in the pediatric population present characteristic clinical features depending on the age of the presentation. Endovascular embolization is currently the treatment of choice for them. It is more important to obtain normal development than to achieve normal morphological appearance. It is also important to understand the difference of pathophysiological features of these diseases in the pediatric and adult population.

Staged Gamma Knife Radiosurgery for Large Skull Base Meningiomas.

PURPOSE: The authors have been treating skull base meningiomas using relatively low-dose gamma knife radiosurgery (GKS, ≤ 12 Gy) with acceptable tumor growth control and low morbidity. In the present study, volume-staged, low-dose GKS was performed for large skull base meningiomas with a maximum diameter > 4 cm. In this article, a treatment strategy for volume-staged GKS and results for large skull base meningiomas are described. METHODS: Data from 27 patients with large skull base meningiomas histopathologically diagnosed as WHO grade I or diagnosed by imaging, who underwent volume-staged GKS between March 1995 and September 2018, were reviewed. Among these patients, 24 were followed-up for > six months. The tumor was located in the parasellar region in nine patients, cavernous sinus region in four, petroclival region in four, petrocavernous sinus region in four, cerebellopontine angle region in two, and in the tent in one. The mean tumor diameters ranged from 31 to 47.8 mm (median 39.4 mm), with tumor volumes between 14.7 and 49.5 cm3 (median 27.5 cm3). RESULTS: The prescribed radiation dose was 8-12 Gy (median 10 Gy). The treatment interval between the first and second GKS was three to nine months (median 5.5 months). The median duration of follow-up after the first GKS was 84 months (range 6-204 months). Tumor volume decreased in nine (37.5%) patients, remained stable in nine (37.5%), and increased (local failure) in six (25%). The actuarial progression-free local control rate was 88% at three years, 78% at five years, 70% at 10 years, and 70% at 15 years. Neurological status improved in three (12.5%) patients, was unchanged in 16 (66.5%), and deteriorated in five (21%). Permanent radiation injury occurred in one (4%) patient. CONCLUSION: Volume-staged GKS demonstrated the usefulness for large skull meningiomas > 4 cm in diameter, over a long-term follow-up period.

Intracavernous Hemangiopericytoma: Case Report and Review of the Literature.

Intracavernous hemangiopericytoma/solitary fibrous tumor is an extremely rare tumor, with only seven cases reported. We present a case of intracavernous hemangiopericytoma/solitary fibrous tumor and review all cases reported in the literature. A 67-year-old man experienced numbness over the left half of the face. Magnetic resonance imaging revealed a left intracavernous tumor extending into Meckel's cave and the posterior fossa. We performed gamma knife surgery (GKS) which a prescribed dose to the tumor of 12 Gy, but tumor recurred 43 months after GKS. We performed partial tumor resection via a subtemporal interdural approach. The pathological diagnosis was hemangiopericytoma. Postoperatively, we performed second GKS with a prescribed dose of 15 Gy. Diplopia and ptosis improved markedly and the tumor initially reduced in size, but tumor regrowth was seen again 29 months after second GKS. Third GKS was performed with a prescribed dose of 15 Gy. Recurrence was not seen at 18 months after third GKS, but was identified about 2 years after third GKS. We performed fourth GKS with a prescribed dose to the residual tumor of 16 Gy. We report a rare case of intracavernous hemangiopericytoma originating in the cavernous sinus, but distinguishing between hemangiopericytoma and schwannoma is difficult for round, intracavernous tumors showing homogeneous enhancement without flow voids. GKS might be one of the options for residual and recurrent intracavernous hemangiopericytomas.

Oil Gel-Based Phantom for Evaluating Quantitative Accuracy of Speed of Sound Measured in Ultrasound Computed Tomography.

To evaluate the quantitative accuracy of the measured speed of sound in ultrasound computed tomography for breast imaging, it is necessary to use a phantom with inclusions whose speed of sound is known. Accordingly, a phantom with known-speed-of-sound inclusions (e.g., containing water and saltwater solution) under the control of temperature was developed. In addition, an oil gel was used as the phantom material for mimicking wave refraction from fatty breast tissue to dense breast tissue. The oil gel was generated by adding SEBS (styrene-ethylene/butylene-styrene, 10% w/w) to paraffin oil. The oil gel-based phantom has a cylindrical shape and contains rod-shaped inclusions that can be filled with water or saltwater solution (3.5% w/w sodium chloride in water). When temperature increases, the speed of sound in the water increases, while that in the oil gel decreases; in particular, the speed of sound in the oil gel was higher than that in the water at temperatures <20.6°C, while the speed of sound in the oil gel was lower than that in the water at temperatures >20.6°C. It has been reported that the speed of sound in dense breast tissue is higher than that in water, while that in fatty breast tissue is lower than that in water. Ultrasound is refracted owing to the difference between the speed of sound in the breast tissue and that in the background water. By controlling the temperatures of the oil gel and water, the oil gel-based phantom simulates the refraction of an ultrasound wave from fatty breast tissue to dense breast tissue. For 43 d, the variation ranges of the speed of sound and attenuation in the oil gel in the reconstructed images were 0.7 m/s and 0.03 dB/MHz/cm, respectively. The concentration of the saltwater solution in the polyacrylamide gel-based phantom decreased from 1% (w/w) to 0.48% (w/w) after 24 h, while that in the oil-gel-based phantom was constant. In addition, magnetic resonance imaging of the oil gel-based phantom revealed that NiSO4 solution was stably contained in the phantom for 42 d. It is therefore concluded that the liquid cannot penetrate the oil gel. This oil gel-based phantom with such high temporal stability is suitable for multicenter distribution and may be used for standardization of data acquisition and image reconstruction across centers.