Fully Automated MRI Segmentation and Volumetric Measurement of Intracranial Meningioma Using Deep Learning.

BACKGROUND: Accurate and rapid measurement of the MRI volume of meningiomas is essential in clinical practice to determine the growth rate of the tumor. Imperfect automation and disappointing performance for small meningiomas of previous automated volumetric tools limit their use in routine clinical practice. PURPOSE: To develop and validate a computational model for fully automated meningioma segmentation and volume measurement on contrast-enhanced MRI scans using deep learning. STUDY TYPE: Retrospective. POPULATION: A total of 659 intracranial meningioma patients (median age, 59.0 years; interquartile range: 53.0-66.0 years) including 554 women and 105 men. FIELD STRENGTH/SEQUENCE: The 1.0 T, 1.5 T, and 3.0 T; three-dimensional, T1 -weighted gradient-echo imaging with contrast enhancement. ASSESSMENT: The tumors were manually segmented by two neurosurgeons, H.K. and C.-K.P., with 10 and 26 years of clinical experience, respectively, for use as the ground truth. Deep learning models based on U-Net and nnU-Net were trained using 459 subjects and tested for 100 patients from a single institution (internal validation set [IVS]) and 100 patients from other 24 institutions (external validation set [EVS]), respectively. The performance of each model was evaluated with the Sørensen-Dice similarity coefficient (DSC) compared with the ground truth. STATISTICAL TESTS: According to the normality of the data distribution verified by the Shapiro-Wilk test, variables with three or more categories were compared by the Kruskal-Wallis test with Dunn's post hoc analysis. RESULTS: A two-dimensional (2D) nnU-Net showed the highest median DSCs of 0.922 and 0.893 for the IVS and EVS, respectively. The nnU-Nets achieved superior performance in meningioma segmentation than the U-Nets. The DSCs of the 2D nnU-Net for small meningiomas less than 1 cm3 were 0.769 and 0.780 with the IVS and EVS, respectively. DATA CONCLUSION: A fully automated and accurate volumetric measurement tool for meningioma with clinically applicable performance for small meningioma using nnU-Net was developed. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Endoscopic biopsy of pineal tumors: two burr hole trans-foramen of Monro approach and endonasal trans-tuber cinereum approach.

INTRODUCTION: The pineal region is a challenging area for neurosurgeons due to its innate anatomical features, such as its deep location, surrounding large draining veins, and adjacent critical neural structures. DISCUSSION: There is a high proportion of malignant tumors in the pineal gland, especially in children, and they are frequently accompanied by obstructive hydrocephalus. These cases require that surgical procedures can make a pathological diagnosis to guide further treatment strategies and immediately resolve increased intracranial pressure. Simultaneous endoscopic third ventriculostomy and biopsy have been regarded as the first-line surgical intervention before establishing a definite treatment plan. However, it is not always successful because various factors affect the surgical procedures, such as the location and extent of the tumor, degree of ventriculomegaly, location and size of the massa intermedia, and size of the foramen of Monro. CONCLUSION: Here, we briefly reviewed the points to be considered in endoscopic biopsy of pineal tumors and introduced an alternative surgical procedure, the endoscopic endonasal trans-tuber cinereum approach, to surmount the anatomical hurdles.

Safety of endoscopic endonasal biopsy for the pituitary stalk-hypothalamic lesions.

PURPOSE: The indications for and the optimal biopsy approach in pituitary stalk-hypothalamic (PsH) lesions are controversial. Biopsies through an endoscopic endonasal approach (EEA) for PsH lesions have often been considered to cause the infundibulo-tuberal syndrome. The purpose of this study was to analyze the surgical and endocrinological safety of EEA biopsies for PsH lesions. METHODS: A total of 39 consecutive patients who underwent an EEA biopsy between June 2011 and August 2020 in a single institute were retrospectively analyzed. The ophthalmological and endocrinological outcomes were assessed before and after surgery. RESULTS: PsH lesions were confirmed to be diverse pathological diagnoses, ranging from lymphocytic hypophysitis to diffuse midline glioma, and the most common pathologic diagnosis was a germinoma (18 patients, 46.2%). No patients developed visual deterioration after the biopsy. In patients without preoperative panhypopituitarism, 13 out of 28 patients (46.4%) developed new anterior pituitary hormonal deficiencies after the biopsy. When the tissue was collected from the stalk, the endocrinological deterioration rate was 100% (6 of 6 patients), while the rate was 31.8% (7 of 22 patients) when tissue could be harvested from an extra-stalk lesion. The rate of newly developed permanent diabetes insipidus after surgery was 40.9% (9 of 22 patients). The median surgery time was 125 min, and there was no postoperative CSF leakage or infections noted. CONCLUSIONS: An EEA biopsy for PsH lesions is a safe and efficient surgical method unless the tissue is collected from the stalk.

Serum copeptin levels at day two after pituitary surgery and ratio to baseline predict postoperative central diabetes insipidus.

PURPOSE: Central diabetes insipidus is a complication that may occur after pituitary surgery and has been difficult to predict. This study aimed to identify the cutoff levels of serum copeptin and its optimal timing for predicting the occurrence of central diabetes insipidus in patients who underwent transsphenoidal surgery. METHODS: This was a prospective observational study of patients who underwent transsphenoidal surgery for pituitary gland or stalk lesions. Copeptin levels were measured before surgery, 1 h after extubation, and on postoperative days 1, 2, 7, and 90. RESULTS: Among 73 patients, 14 (19.2%) and 13 (17.8%) patients developed transient and permanent central diabetes insipidus, respectively. There was no significant difference in copeptin levels before surgery and 1 h after extubation; copeptin levels on postoperative days 1, 2, 7, and 90 were significantly lower in patients with permanent central diabetes insipidus than in those without central diabetes insipidus. Copeptin measurement on postoperative day 2 exhibited the highest performance for predicting permanent central diabetes insipidus among postoperative days 1, 2, and 7 (area under the curve [95% confidence interval] = 0.754 [0.632-0.876]). Serum copeptin level at postoperative day 2(< 3.1 pmol/L) showed a sensitivity of 92.3% and a negative predictive value of 97.1%. The ratio of copeptin at postoperative day 2 to baseline (< 0.94) presented a sensitivity of 84.6% and a negative predictive value of 94.9%. The copeptin levels > 3.4 and 7.5 pmol/L at postoperative day 2 and 7 may have ruled out the occurrence of CDI with a negative predictive value of 100%. CONCLUSION: The copeptin level at postoperative day 2 and its ratio to baseline can predict the occurrence of permanent central diabetes insipidus after pituitary surgery.

Diffusion Tensor Imaging and Neurite Orientation Dispersion and Density Imaging Assessment of Optic Pathway Function in Patients With Anterior Visual Pathway Compression.

BACKGROUND: In patients with sellar or parasellar tumors, it is crucial to evaluate visual field impairment in the preoperative stage and to predict visual field improvement after the surgery. The purpose of this study was to investigate the associations of diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) parameters in the optic radiations with preoperative and postoperative visual field impairment. METHODS: This prospective study included 81 participants with sellar or parasellar tumors. Multishell diffusion imaging and a visual field impairment score (VFIS) were acquired before and after the surgery. The multishell diffusion-weighted imaging was acquired to measure the neurite density and neurite orientation dispersion, as well as the diffusivity. DTI parameters were fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, and radial diffusivity (RD). NODDI provided intracellular volume fraction (Vic), the orientation dispersion index, and isotropic volume fraction (Viso). The associations of DTI and NODDI parameters in the optic radiations with VFIS were investigated, adjusting for age, tumor height, and symptom duration. RESULTS: Among 162 optic radiations, 117 were functionally impaired in the preoperative stage. FA and Vic had significant negative correlations, whereas MD and RD had significant positive correlations with the VFIS (all P < 0.001). In the preoperative stage, lower FA (P = 0.001; odds ratio = 0.750) and Vic (P = 0.003; OR = 0.827) and higher MD (P = 0.007; OR = 1.244) and RD (P < 0.001; OR = 1.361) were significantly associated with the presence of visual field impairment. For the degree of postoperative improvement, preoperative lower Vic (P = 0.034; OR = 0.910) and higher MD (P = 0.037; OR = 1.103) and RD (P = 0.047; OR = 1.090) were significantly associated with more postoperative improvement. CONCLUSIONS: DTI and NODDI parameters in the optic radiations were correlated with VFIS and associated with preoperative visual field impairments and postoperative improvement. It may help in predicting visual field improvement after the surgery in patients with sellar or parasellar tumors.

Sevoflurane anesthesia rather than propofol anesthesia is associated with 3-month postoperative hypocortisolism in patients undergoing endoscopic transsphenoidal surgery for non-functional pituitary adenoma with preoperative normal hypothalamic-pituitary-adrenal axis.

PURPOSE: The effects of anesthetic technique on intermediate-term postoperative adrenocorticotropic hormone (ACTH) functional outcomes have not been fully determined in non-functioning pituitary adenoma (NFPA) patients. Postoperative hypocortisolism is potentially life-threatening and requires steroid replacement after pituitary surgery. The present study determined whether sevoflurane anesthesia was predictive of 3-month postoperative hypocortisolism in NFPA patients with preoperative normal hypothalamic-pituitary-adrenal (HPA) axis. METHODS: Demographics, preoperative pituitary hormone status, intraoperative data, and tumor characteristics were retrospectively collected from 429 NFPA patients, who had preoperative normal HPA axis and underwent endoscopic transsphenoidal surgery. Patients were divided into two groups based on intraoperative anesthetic technique: sevoflurane-based inhalation anesthesia group (n = 74) and propofol-based intravenous anesthesia group (n = 355). After propensity score matching, 73 patients were selected in each group and the incidence of 3-month postoperative hypocortisolism (primary outcome measure) was compared between the two groups. RESULTS: The incidence of 3-month postoperative hypocortisolism was higher in the sevoflurane anesthesia group than the propofol anesthesia group before (n = 20[27.0%] vs. n = 49[13.8%], P = 0.008) and after (n = 20 [27.4%] vs. n = 5 [6.8%], P = 0.002) propensity score matching, respectively. Sevoflurane anesthetic use (odds ratio [95% CI] 5.37[1.80-15.98], P = 0.003) and postoperative steroid administration (2.89 [1.06-7.92], P = 0.039) were predictors of 3-month postoperative hypocortisolism. CONCLUSION: In patients with preoperative normal HPA axis undergoing endoscopic transsphenoidal surgery for NFPA, sevoflurane anesthesia and postoperative steroid administration were associated with the development of 3-month postoperative hypocortisolism. A large-scale prospective study is needed to confirm the negative association between sevoflurane anesthesia and postoperative ACTH functional outcome.

Absolute quantification of tumor-infiltrating immune cells in high-grade glioma identifies prognostic and radiomics values.

PURPOSE: To understand the tumor immune microenvironment precisely, it is important to secure the quantified data of tumor-infiltrating immune cells, since the immune cells are true working unit. We analyzed unit immune cell number per unit volume of core tumor tissue of high-grade gliomas (HGG) to correlate their immune microenvironment characteristics with clinical prognosis and radiomic signatures. METHODS: The number of tumor-infiltrating immune cells from 64 HGG core tissue were analyzed using flow cytometry and standardized. After sorting out patient groups according to diverse immune characteristics, the groups were tested if they have any clinical prognostic relevance and specific radiomic signature relationships. Sparse partial least square with discriminant analysis using multimodal magnetic resonance images was employed for all radiomic classifications. RESULTS: The median number of CD45 + cells per one gram of HGG core tissue counted 865,770 cells which was equivalent to 8.0% of total cells including tumor cells. There was heterogeneity in the distribution of immune cell subpopulations among patients. Overall survival was significantly better in T cell-deficient group than T cell-enriched group (p = 0.019), and T8 dominant group than T4 dominant group (p = 0.023). The number of tumor-associated macrophages (TAM) and M2-TAM was significantly decreased in isocitrate dehydrogenase mutated HGG. Radiomic signature classification showed good performance in predicting immune phenotypes especially with features extracted from apparent diffusion coefficient maps. CONCLUSIONS: Absolute quantification of tumor-infiltrating immune cells confirmed the heterogeneity of immune microenvironment in HGG which harbors prognostic impact. This immune microenvironment could be predicted by radiomic signatures non-invasively.

Cephalocaudal tumor diameter is a predictor of diabetes insipidus after endoscopic transsphenoidal surgery for non-functioning pituitary adenoma.

PURPOSE: Diabetes insipidus (DI) develops commonly after endoscopic transsphenoidal surgery (ETS). We retrospectively investigated the incidence, onset, duration and predictors of DI after ETS in patients with non-functioning pituitary adenoma (NFPA). METHODS: A total of 168 patients who underwent ETS to remove NFPAs were included. Various perioperative data on demographics, comorbidities, previous treatments, perioperative hormone deficiencies, tumor characteristics, surgery, anesthesia, intraoperative fluid balance, perioperative laboratory findings, postoperative complications, readmission and hospital length of stay were collected and analyzed. Patients were diagnosed with DI and treated with desmopressin when they showed urine output > 5 mL/kg/hr with a serum sodium concentration > 145 mmol/L or an increase ≥ 3 mmol/L in serum sodium concentration between two consecutive tests after surgery. DI was considered permanent when desmopressin was prescribed for > 6 months after surgery. RESULTS: Seventy-seven (45.8%) patients experienced postoperative DI and 10 (6.0%) patients suffered from permanent DI. The median onset of DI and the median duration of transient DI were postoperative day 1 and 5 days, respectively. In multivariable logistic regression analysis, cephalocaudal tumor diameter (odds ratio [95% confidence interval] 2.59 [1.05-6.36], P = 0.038) was related to postoperative DI. In receiver operating characteristic analysis, its area under the curve was 0.68 (95% confidence interval 0.59-0.76, P < 0.001). Its optimal cutoff value that maximized the sum of sensitivity and specificity for postoperative DI was 2.7 cm. CONCLUSIONS: Postoperative DI was observed in 45.8% of patients undergoing ETS to remove NFPAs. A large cephalocaudal tumor diameter was predictive of postoperative DI in such patients.

Development of an inside-out augmented reality technique for neurosurgical navigation.

OBJECTIVE: With the advancement of 3D modeling techniques and visualization devices, augmented reality (AR)-based navigation (AR navigation) is being developed actively. The authors developed a pilot model of their newly developed inside-out tracking AR navigation system. METHODS: The inside-out AR navigation technique was developed based on the visual inertial odometry (VIO) algorithm. The Quick Response (QR) marker was created and used for the image feature-detection algorithm. Inside-out AR navigation works through the steps of visualization device recognition, marker recognition, AR implementation, and registration within the running environment. A virtual 3D patient model for AR rendering and a 3D-printed patient model for validating registration accuracy were created. Inside-out tracking was used for the registration. The registration accuracy was validated by using intuitive, visualization, and quantitative methods for identifying coordinates by matching errors. Fine-tuning and opacity-adjustment functions were developed. RESULTS: ARKit-based inside-out AR navigation was developed. The fiducial marker of the AR model and those of the 3D-printed patient model were correctly overlapped at all locations without errors. The tumor and anatomical structures of AR navigation and the tumors and structures placed in the intracranial space of the 3D-printed patient model precisely overlapped. The registration accuracy was quantified using coordinates, and the average moving errors of the x-axis and y-axis were 0.52 ± 0.35 and 0.05 ± 0.16 mm, respectively. The gradients from the x-axis and y-axis were 0.35° and 1.02°, respectively. Application of the fine-tuning and opacity-adjustment functions was proven by the videos. CONCLUSIONS: The authors developed a novel inside-out tracking-based AR navigation system and validated its registration accuracy. This technical system could be applied in the novel navigation system for patient-specific neurosurgery.

Long-term Outcome of Microscopic Transsphenoidal Surgery for Prolactinomas as an Alternative to Dopamine Agonists.

BACKGROUND: Although long-term dopamine agonist (DA) therapy is recommended as a first-line treatment for prolactinoma, some patients may prefer surgical treatment because of the potential adverse effects of long-term medication, or the desire to become pregnant. This study aimed to determine whether surgical treatment of prolactinomas could be an alternative to DA therapy. METHODS: In this retrospective study, 96 consecutive patients (74 female, 22 male) underwent primary pituitary surgery without long-term DA treatment for prolactinomas at a single institution from 1990 to 2010. All patients underwent primary surgical treatment in the microscopic transsphenoidal approach (TSA). RESULTS: The median age and median follow-up period were 31 (16-73) years and 139.1 (12.2-319.6) months, respectively. An initial overall remission was accomplished in 47.9% (46 of 96 patients, 33 macroadenomas, and 13 microadenomas) of patients. DA dose reduction was achieved in all patients after TSA. A better remission rate was independently predicted by lower diagnostic prolactin levels and by a greater extent of surgical resection. Overall remission at the last follow-up was 33.3%, and the overall recurrence rate was 30.4%. The permanent complication rate was 3.1%, and there was no mortality. CONCLUSION: TSA can be considered a safe and potentially curative treatment for selective microprolactinomas as an alternative to treatment with a long-term DA.

Endoscopic endonasal skull base surgery for pediatric brain tumors.

PURPOSE: The utility of endoscopic endonasal skull base surgery (EES) in various pathologic entities in adults has been published in the literature. However, the role of EES in children has not been clearly elucidated. We evaluated the feasibility of EES in children with brain tumors. METHODS: We retrospectively reviewed clinical features, surgical outcomes, and complications in children who underwent EES for intracranial and skull base tumors at a single institution from July 2010 to October 2018. RESULTS: A total of 82 patients underwent EESs for 77 intracranial and 5 skull base bony tumors. The mean age at diagnosis was 11.4 years (range 4-18 years), and the mean follow-up period was 46.8 months. The most common tumors were craniopharyngioma in the intracranial tumor and chordoma in the skull base. Gross total resection was the goal of surgery in 55 patients and achieved in 90.9%. The vision was improved in 76.1% of patients with visual impairments. Preoperatively, various endocrinological deficiencies were revealed in 73.7% of 76 patients with hypothalamus-pituitary lesions, and the hyposomatotropism was most common. Endocrinological status was improved only in 10. Aseptic or bacterial meningitis (7.3%) was the most common surgical complication, and the cerebrospinal fluid leakage rate was 2.4%. CONCLUSIONS: EES provides favorable neurological outcomes with acceptable risk for children with brain tumors. The high incidence of endocrinological deficits in cases with hypothalamus-pituitary lesions emphasizes the importance of judicious pre- and postoperative evaluation.

Optimal strategy of gamma knife radiosurgery for craniopharyngiomas.

OBJECT: To analyze the outcomes of gamma knife radiosurgery (GKS) for craniopharyngiomas and elucidate the optimal strategy. METHODS: Between 1998 and 2016, 35 patients underwent GKS for the treatment of 40 recurrent or residual craniopharyngiomas. Among 40 GKSs, 22 procedures were single-session GKSs and 18 procedures were fractionated GKSs. In cases of single-session GKS, the median marginal dose was 15 Gy (range 10-20 Gy). In cases of fractionated GKS, the median marginal dose was 6 Gy (range 5-7.5 Gy) of three fractions. The radiation dose was calculated to the biologic equivalent dose (BED) using α/ß ratios of 10 and 2. RESULT: The location of the tumor, the distance between the optic nerve and tumor (> 10 mm), BED 10 (> 35 Gy), and BED2 (> 80 Gy) were statistically significant with overall response rate (P = 0.008, 0.02, 0.03, and 0.002, respectively). There was a statistically significant difference in progression-free survival according to the distance between the optic nerve and tumor (> 10 mm) and the location of tumor (P = 0.03 and 0.03, respectively). Multivariate logistic regression analysis showed the hypothalamus group had an odds ratio of 0.04 compared with the suprasellar group for tumor progression. The group with BED2 > 80 Gy had an odds ratio of 0.049 compared with the group with BED2 < 80 Gy. CONCLUSION: A sufficient dose is required for treating craniopharyngiomas using single-session and fractionated GKS. The outcomes of GKS can be predicted according to the location of tumor, the distance between the optic nerve and tumor and BED value.

The efficacy of medical treatment in patients with acromegaly in clinical practice.

Although somatostatin analogues (SSAs) are recommended as the first-line medical therapy for acromegaly, dopamine agonists (DAs) are also a therapeutic option for treatment. We aimed to assess and compare the efficacies of DAs and SSAs in treating acromegaly in clinical practice. We included 89 patients with acromegaly who took DAs (bromocriptine [BCT], n = 63; cabergoline [CAB], n = 11) or SSAs (n = 15) as a primary medical therapy for more than 3 months in the Seoul National University Hospital. The CAB (45.5%) and SSA (33.3%) groups achieved random GH levels of <2.5 ng/mL and the normal IGF-1 levels were significantly higher than in the BCT group (11.1%) (p = 0.009). We further included all the patients with acromegaly (n = 132) who had taken CAB, BCT, and SSAs as first- or second-line medical therapy. The CAB group showed similar efficacy as the SSA group in terms of the GH and insulin-like growth factor-1 (IGF-1) levels (57.6% for random GH level <2.5 ng/mL, 42.4% for normal IGF-1 levels, 36.4% for both). Logistic regression analysis revealed that medications, age, GH level, or IGF-1 level before medication, hyperprolactinemia, and prior gamma-knife surgery or radiation therapy, did not affect the therapeutic response. High pretreatment GH levels predicted poor treatment outcomes (odds ratio [95% confidence interval] = 0.95 [0.90-0.99]). CAB was effective in treating acromegaly at a relatively lower cost in patients with low pretreatment GH levels.

A Retrospective Analysis of the Outcomes of Dural Arteriovenous Fistulas Treated with Gamma Knife Radiosurgery: A Single-Institution Experience.

BACKGROUND: Gamma knife radiosurgery (GKRS) has recently been used as a treatment modality for dural arteriovenous fistula (DAVF). OBJECTIVE: To retrospectively analyze the outcomes of GKRS for DAVF at a single institute. METHODS: Between 1998 and 2016, a total of 20 patients underwent GKRS for DAVF. After excluding 4 patients with > 12 months of follow-up, 16 patients were enrolled in this study. Twelve patients had undergone embolization prior to GKRS. The most common location was the cavernous sinus (CS). The median clinical and radiological follow-up durations were 87.5 (range 24-186) months and 44.5 (range 14-174) months. RESULTS: Ten (62.5%) of the 16 DAVFs were obliterated; 8 were confirmed on angiography. Five cases resulted in small, residual DAVFs, and one case remained unchanged. The obliteration rate of GKRS for CS DAVF was significantly higher than that for non-CS DAVF (100 vs. 40%; p = 0.034). Fifteen out of 16 patients (94%) had a favorable outcome, and the remaining patient had an unfavorable outcome. Hemorrhage after GKRS occurred in only 1 patient, who presented with seizure. CONCLUSIONS: GKRS is a safe and effective treatment modality for DAVF in combination with a traditional treatment option such as endovascular embolization or microsurgery.

Best candidates for dopamine agonist withdrawal in patients with prolactinomas.

PURPOSE: Dopamine agonist (DA) therapy is recommended as the first-line treatment for prolactinomas. However, it requires long treatment duration, and a high recurrence rate after DA withdrawal has been reported. We aimed to elucidate the predictors for long-term remission following DA withdrawal and propose the best candidates who can achieve complete remission after DA withdrawal. METHODS: In a retrospective cohort study, we included 89 patients with prolactinoma who have withdrawn DAs with normal prolactin (PRL) levels at Seoul National University Hospital, from 2000 to 2016. Patient's data were retrieved from the electronic medical records. RESULTS: The median age and median treatment duration of the study patients were 33 (15-73) years and 69.5 (8.3-277.4) months, respectively. The recurrence rate after drug withdrawal was 57.3% during the 23.9 (3.0-176.8) month follow-up period. Age, gender, baseline PRL level, and baseline maximum tumor diameter were similar between the remission and recurrence group. In the Cox-proportional hazard model analysis, the significant predictors for remission were nadir PRL level of <1 ng/dL (hazard ratio [95% confidence interval] = 0.37 [0.18-0.74]), invisible tumors on magnetic resonance imaging (MRI) (0.42 [0.24-0.74]), and treatment duration of >72 months (0.54 [0.30-0.96]). Of the subjects who met all the three criteria, 66.7% achieved long-term remission. CONCLUSIONS: Patients who have no tumor visible on MRI, have a nadir PRL level <1 ng/dL during drug treatment, and received drug treatment for >6 years may be the best candidates for DA withdrawal.

Gamma Knife Surgery for Recurrent or Residual Supratentorial Primitive Neuroectodermal Tumors.

BACKGROUND: Supratentorial primitive neuroectodermal tumors (PNETs) are highly malignant and rare tumors of the central nervous system. OBJECTIVES: The aim of this study was to determine the role of Gamma Knife surgery (GKS) as a salvage treatment option for patients with recurrent or residual supratentorial PNETs. METHODS: Between 1998 and 2014, 11 patients with supratentorial PNETs were retrospectively analyzed. This series consisted of 7 male and 4 female patients. The median age was 17 years. All patients received surgical resection followed by adjuvant therapy. The median time from operation to the first GKS treatment was 72.5 months. The median tumor volume was 17.5 cm3, and the median marginal dose was 11.5 Gy. RESULTS: 15 (65%) of the 23 tumors had been controlled. The actuarial local tumor control rate was 91% at 3 months, 73% at 6 months, and 44% at 12 months. At the time of analysis, 9 (82%) of the patients had died. The median survival time after the first GKS session was 17 months. The median survival time from the initial diagnosis was 65 months. No adverse radiation effect after GKS treatment occurred in any patient. CONCLUSIONS: GKS treatment might be an effective salvage treatment option for recurrent or residual supratentorial PNETs after multimodal treatment.

Evaluation of the degree of arteriovenous shunting in intracranial arteriovenous malformations using pseudo-continuous arterial spin labeling magnetic resonance imaging.

INTRODUCTION: Intracranial arteriovenous malformations (AVMs) display venous signals on arterial spin labeling (ASL) magnetic resonance (MR) imaging due to the presence of arteriovenous shunting. Our aim was to quantitatively correlate AVM signal intensity on ASL with the degree of arteriovenous shunting estimated on digital subtraction angiography (DSA) in AVMs. METHODS: MR imaging including pseudo-continuous ASL at 3 T and DSA were obtained on the same day in 40 patients with intracranial AVMs. Two reviewers assessed the nidus and venous signal intensities on ASL images to determine the presence of arteriovenous shunting. Interobserver agreement on ASL between the reviewers was determined. ASL signal intensity of the AVM lesion was correlated with AVM size and the time difference between normal and AVM venous transit times measured from the DSA images. RESULTS: Interobserver agreement between two reviewers for nidus and venous signal intensities was excellent (κ = 0.80 and 1.0, respectively). Interobserver agreement regarding the presence of arteriovenous shunting was perfect (κ = 1.0). AVM signal intensity showed a positive relationship with the time difference between normal and AVM venous transit times (r = 0.638, P < 0.001). AVM signal intensity also demonstrated a positive relationship with AVM size (r = 0.561, P < 0.001). CONCLUSION: AVM signal intensity on ASL in patients with AVM correlates well with the degree of early vein opacification on DSA, which corresponds to the degree of arteriovenous shunting.

Langerhans cell histiocytosis causing acute optic neuropathy.

PURPOSE: Langerhans cell histiocytosis (LCH) arising from the skull base is a rare acute optic neuropathy cause. We describe a clinical approach for the purpose of optic nerve decompression and simultaneous lesion excision. This is the first case of visual improvement following decompression operation via endoscopic endonasal approach for acute optic neuropathy that is produced by LCH. METHODS: An 11-year-old boy presented with a 2-week history of visual deterioration. Radiological evidence of compressive optic neuropathy by an expansile soft tissue mass around the optic canal was observed. The patient underwent an endoscopic endonasal optic nerve decompression and subtotal tumor removal. RESULTS: His visual impairment improved dramatically after the operation. CONCLUSIONS: Acute optic neuropathy can be elicited by LCH arising in the sphenoid-ethmoid bone. Early decompression is the key to vision salvage. An endoscopic endonasal approach may be a good therapeutic option in this situation.

Stereotactic radiosurgery for cavernous sinus hemangiomas.

We performed this retrospective study to analyze the outcome of patients with cavernous sinus hemangioma (CSH) after stereotactic radiosurgery (SRS). We analyzed 19 patients with CSHs who were treated with SRS between 1998 and 2011. The median age of the patients was 50 years (range, 35-73 years), and 16 (84.2%) of the patients were female. SRS was performed as a primary treatment for 18 patients and to treat a residual lesion after surgical resection in one patient. Nine (47.4%) patients had cranial neuropathies in 14 cranial nerves before SRS, whereas five (26.3%) patients were initially asymptomatic. The mean volume of the CSHs was 6.1 ± 7.2 cm(3) (range, 0.3-32.3 cm(3)), and the median marginal dose at the 50% isodose line was 14.5 Gy (range, 11.5-16.0 Gy). The mean follow-up period was 37 months (range, 12-85 months). At the last follow-up, the lesion volume had decreased in all patients. The average tumor volume had decreased to 26% (range, 0-70%) of the initial volume at the last follow-up MRI. The first follow-up MRI, performed 6.1 ± 1.0 months after the SRS, showed that the tumor volume had decreased to 41% (range, 0-88%) of the initial volume. All 14 of the cranial neuropathies observed before SRS had improved, with complete remission in 12 (85.7%) cranial nerves and partial remission in two (14.3%). There were no radiation-induced neuropathies or complications during the follow-up period. SRS appears to be an effective and safe treatment modality for the management of CSHs.

Extended endoscopic endonasal approach for recurrent or residual adult craniopharyngiomas.

BACKGROUND: The aim of this study was to evaluate the effectiveness of the extended endoscopic endonasal transsphenoidal approach (TSA) for recurrent or residual craniopharyngiomas, focusing on the extent of tumor resection and complications resulting from surgery at a single institution. METHODS: Twelve adult patients (six men and six women) underwent extended endoscopic endonasal TSA for a recurrent or residual craniopharyngioma after a previous surgical intervention at a single institution by a single surgeon. The mean number of surgeries patients had undergone before TSA was 1.3 (range, 1-3). The mean period between patients' most recent surgery and extended TSA was 55.9 months (range, 1-184). The mean preoperative (that is, pre-extended TSA) tumor volume was 2.87 cm³. The mean follow-up period was 15.8 months (range, 4-32). We reviewed clinical and radiological features in each case, focusing on the degree of tumor resection as well as endocrinological and ophthalmological outcomes. RESULTS: Gross total resection was achieved in ten patients (83.3 %), and the mean resection rate was 87 % in the other two cases. There were no significant differences between pre- and postoperative endocrine function, except in one patient who suffered postoperative panhypopituitarism resulting in pituitary stalk resection, which was necessary because of obvious tumor involvement. Three patients suffered transient diabetic insipidus (DI). With respect to ophthalmological outcomes, three patients showed improvement, two others showed decline, and the remainder showed no significant changes. CONCLUSION: The extended endoscopic endonasal transsphenoidal approach is an effective and safe surgical approach for treating recurrent or residual craniopharyngioma.