Region-specific DNA hydroxymethylation along the malignant progression of IDH-mutant gliomas

The majority of low-grade isocitrate dehydrogenase-mutant (IDHmt ) gliomas undergo malignant progression (MP), but their underlying mechanism remains unclear. IDHmt gliomas exhibit global DNA methylation, and our previous report suggested that MP could be partly attributed to passive demethylation caused by accelerated cell cycles. However, during MP, there is also active demethylation mediated by ten-eleven translocation, such as DNA hydroxymethylation. Hydroxymethylation is reported to potentially contribute to gene expression regulation, but its role in MP remains under investigation. Therefore, we conducted a comprehensive analysis of hydroxymethylation during MP of IDHmt astrocytoma. Five primary/malignantly progressed IDHmt astrocytoma pairs were analyzed with oxidative bisulfite and the Infinium EPIC methylation array, detecting 5-hydroxymethyl cytosine at over 850,000 locations for region-specific hydroxymethylation assessment. Notably, we observed significant sharing of hydroxymethylated genomic regions during MP across the samples. Hydroxymethylated CpGs were enriched in open sea and intergenic regions (p < 0.001), and genes undergoing hydroxymethylation were significantly associated with cancer-related signaling pathways. RNA sequencing data integration identified 91 genes with significant positive/negative hydroxymethylation-expression correlations. Functional analysis suggested that positively correlated genes are involved in cell-cycle promotion, while negatively correlated ones are associated with antineoplastic functions. Analyses of The Cancer Genome Atlas clinical data on glioma were in line with these findings. Motif-enrichment analysis suggested the potential involvement of the transcription factor KLF4 in hydroxymethylation-based gene regulation. Our findings shed light on the significance of region-specific DNA hydroxymethylation in glioma MP and suggest its potential role in cancer-related gene expression and IDHmt glioma malignancy.

A Case of Trigeminal Neuralgia in an Adult Patient With Lambdoid Synostosis

Trigeminal neuralgia (TN) is characterized by sudden, brief intense pain in the distribution of the unilateral trigeminal nerve (TGN). Neurovascular compression (NVC) of the TGN is the most common cause of TN. Recent studies have suggested that a structural anomaly of the posterior cranial fossa might be involved in the development of TN, and several studies have documented the association between NVC-related TN and congenital posterior cranial deformities in adults. We present the case of a 56-year-old woman with NVC-related TN and unilateral lambdoid synostosis (ULS), along with a literature review, to investigate the relationship between TN and structural anomalies of the posterior fossa. This is the first report of TN in an adult with ULS. Mild and asymptomatic cases of lambdoid synostosis might have a higher incidence of NVC-related TN in association with posterior cranial fossa deformities.

Spinal Dissemination of Pineal Parenchymal Tumors of Intermediate Differentiation Over 10 Years After Initial Treatment: A Case Report

Pineal parenchymal tumors (PPTs) are rare, accounting for less than 0.3% of all primary central nervous system (CNS) tumors. Pineal parenchymal tumors of intermediate differentiation (PPTID) (WHO grade 2 or 3) show an intermediate prognosis between pineocytoma and pineoblastoma. The clinical course is unknown, and the optimal treatment for PPTID, especially for recurrence, has not been determined. We report a case of PPTID with spinal dissemination over 10 years after treatment and survival for four years. A 56-year-old woman presented with headaches and diplopia. Computerized tomography (CT) and magnetic resonance imaging (MRI) revealed a pineal mass, but leptomeningeal dissemination was not identified on whole-spine MRI. Microsurgical gross total tumor resection (GTR) was performed, and the pathological diagnosis was PPTID (grade 3). In addition, a later study found it to harbor a KBTBD4 mutation. She underwent whole-brain radiation therapy with a focal boost. The patient was unable to continue chemotherapy for severe myelosuppression after the first course of treatment. Eleven years after the surgery, she was unable to walk, and a whole-spine MRI revealed multiple masses at C3-4, T4, and cauda equina. Fluorodeoxyglucose-positron emission tomography (FDG-PET) revealed accumulations of the same lesions. No recurrence was observed in the brain. A biopsy of the caudal portion was performed, and the histopathological findings were the same as those of the initial surgery. Spinal dissemination was refractory to chemotherapy but responded to whole spine radiotherapy with focal boost, and she remained tumor-free for four years. We considered good local control with a combination of GTR and subsequent radiation therapy to contribute to long-term survival. The timing of spinal radiation administration is controversial because of the tendency for late cerebrospinal dissemination. The importance of long-term follow-up of the spine and head is emphasized. In PPTID cases with good local control, withholding spinal radiation until spinal dissemination occurs may become a long-term treatment plan.

Postoperative disappearance of leptomeningeal enhancement around the brainstem in glioblastoma

PURPOSE

Leptomeningeal enhancement (LME) suggests leptomeningeal dissemination (LMD) of tumor cells, which is a complication of end-stage glioblastoma, and is associated with a poor prognosis. However, magnetic resonance imaging (MRI) occasionally indicates the disappearance of peri-brainstem LME after surgical resection of glioblastoma. Since preoperative LMD may affect treatment indications, we aimed to analyze the clinical significance of preoperative LME of the brainstem in glioblastoma.

METHODS

We retrospectively collected clinical and radiological data from consecutive patients with glioblastoma and preoperative LME of the brainstem, who were treated at our hospital between 2017 and 2020.

RESULTS

Among 112 patients with glioblastoma, nine (8%) showed preoperative LME of the brainstem. In comparison with tumors without LME, tumor size was significantly associated with the preoperative LME of the brainstem (p = 0.016). In addition, there was a trend toward significance for a relationship between deep tumor location and preoperative LME of the brainstem (p = 0.058). Notably, among six patients who underwent surgical resection for glioblastoma with LME of the brainstem, four showed significant radiological disappearance of the LME on postoperative MRI. This suggests that the LME did not result from LMD in these cases. Moreover, these four patients lived longer than would be expected from the presence of LMD. However, this LME disappearance was not observed after biopsy or chemoradiotherapy.

CONCLUSIONS

These findings suggest that preoperative LME does not necessarily indicate the presence of untreatable LMD; moreover, LME may disappear after surgical tumor resection. Thus, transient preoperative LME could be attributed to other mechanisms, including impaired venous flow due to intratumoral arteriovenous shunts, which can be resolved by reducing the tumor burden.

Long-term outcomes of multidisciplinary treatment combining surgery and stereotactic radiotherapy with Novalis for craniopharyngioma

Craniopharyngiomas are difficult to resect completely, recurrence is frequent, and hypothalamic/pituitary function may be affected after surgery. Therefore, the ideal treatment for craniopharyngiomas is local control with preservation of hypothalamic and pituitary functions. The purpose of this study is to retrospectively evaluate the long-term efficacy and adverse events of stereotactic radiotherapy (SRT) with Novalis for craniopharyngioma. This study included 23 patients with craniopharyngiomas who underwent surgery between 2006 and 2021 and underwent SRT as their first irradiation after surgery. The median post-irradiation observation period was 88 months, with the overall survival rates of 100 % at 10 years and 85.7 % at 20 years. One patient died of adrenal insufficiency 12 years after irradiation. The local control rate of the cystic component was 91.3 % at 5 years, 83.0 % at 15 years, with no increase in the solid component. No delayed impairment of visual or pituitary function due to irradiation was observed. No new hypothalamic dysfunction was observed after radiation therapy. No delayed adverse events such as brain necrosis, cerebral artery stenosis, cerebral infarction, or secondary brain tumors were also observed. SRT was safe and effective over the long term in patients irradiated in childhood as well as adults, with no local recurrence or adverse events. We believe that surgical planning for craniopharyngioma with stereotactic radiotherapy in mind is effective in maintaining a good prognosis and quality of life.

Exploring the impact of super-resolution deep learning on MR angiography image quality

PURPOSE

The aim of this study is to assess the effect of super-resolution deep learning-based reconstruction (SR-DLR), which uses k-space properties, on image quality of intracranial time-of-flight (TOF) magnetic resonance angiography (MRA) at 3 T.

METHODS

This retrospective study involved 35 patients who underwent intracranial TOF-MRA using a 3-T MRI system with SR-DLR based on k-space properties in October and November 2022. We reconstructed MRA with SR-DLR (matrix = 1008 × 1008) and MRA without SR-DLR (matrix = 336 × 336). We measured the signal-to-noise ratio (SNR), contrast, and contrast-to-noise ratio (CNR) in the basilar artery (BA) and the anterior cerebral artery (ACA) and the sharpness of the posterior cerebral artery (PCA) using the slope of the signal intensity profile curve at the half-peak points. Two radiologists evaluated image noise, artifacts, contrast, sharpness, and overall image quality of the two image types using a 4-point scale. We compared quantitative and qualitative scores between images with and without SR-DLR using the Wilcoxon signed-rank test.

RESULTS

The SNRs, contrasts, and CNRs were all significantly higher in images with SR-DLR than those without SR-DLR (p < 0.001). The slope was significantly greater in images with SR-DLR than those without SR-DLR (p < 0.001). The qualitative scores in MRAs with SR-DLR were all significantly higher than MRAs without SR-DLR (p < 0.001).

CONCLUSION

SR-DLR with k-space properties can offer the benefits of increased spatial resolution without the associated drawbacks of longer scan times and reduced SNR and CNR in intracranial MRA.

Transcriptomic and epigenetic dissection of spinal ependymoma (SP-EPN) identifies clinically relevant subtypes enriched for tumors with and without NF2 mutation

Ependymomas encompass multiple clinically relevant tumor types based on localization and molecular profiles. Tumors of the methylation class "spinal ependymoma" (SP-EPN) represent the most common intramedullary neoplasms in children and adults. However, their developmental origin is ill-defined, molecular data are scarce, and the potential heterogeneity within SP-EPN remains unexplored. The only known recurrent genetic events in SP-EPN are loss of chromosome 22q and NF2 mutations, but neither types and frequency of these alterations nor their clinical relevance have been described in a large, epigenetically defined series. Transcriptomic (n = 72), epigenetic (n = 225), genetic (n = 134), and clinical data (n = 112) were integrated for a detailed molecular overview on SP-EPN. Additionally, we mapped SP-EPN transcriptomes to developmental atlases of the developing and adult spinal cord to uncover potential developmental origins of these tumors. The integration of transcriptomic ependymoma data with single-cell atlases of the spinal cord revealed that SP-EPN display the highest similarities to mature adult ependymal cells. Unsupervised hierarchical clustering of transcriptomic data together with integrated analysis of methylation profiles identified two molecular SP-EPN subtypes. Subtype A tumors primarily carried previously known germline or sporadic NF2 mutations together with 22q loss (bi-allelic NF2 loss), resulting in decreased NF2 expression. Furthermore, they more often presented as multilocular disease and demonstrated a significantly reduced progression-free survival as compared to SP-EP subtype B. In contrast, subtype B predominantly contained samples without NF2 mutation detected in sequencing together with 22q loss (monoallelic NF2 loss). These tumors showed regular NF2 expression but more extensive global copy number alterations. Based on integrated molecular profiling of a large multi-center cohort, we identified two distinct SP-EPN subtypes with important implications for genetic counseling, patient surveillance, and drug development priorities.

A Rare Case of Adult Poorly Differentiated Chordoma of the Skull Base With Rapid Progression and Systemic Metastasis: A Review of the Literature

Chordoma is a rare tumor that arises from chordal tissue during fetal life. Recently, the concept of poorly differentiated chordoma, a subtype of chordoma characterized by loss of SMARCB1/INI1 with a poorer prognosis than conventional chordomas, was established. It predominantly occurs in children and is rare in adults. Here, we report a rare adult case of poorly differentiated chordoma of the skull base with a unique course that rapidly systemically metastasized and had the shortest survival time of any adult chordoma reported to date. The patient was a 32-year-old male with a chief complaint of diplopia. MRI showed a widespread neoplastic lesion with the clivus as the main locus. Endoscopic extended transsphenoidal tumor resection was performed. Pathological findings showed that the tumor was malignant, and immunohistochemistry revealed a Ki-67 labeling index of 80%, diffusely positive brachyury, and loss of INI1 expression. The final diagnosis was poorly differentiated chordoma. Postoperatively, the residual tumor in the right cavernous sinus showed rapid growth. The patient was promptly treated with gamma knife three fractions. The residual tumor regressed, but the tumor developed systemic metastasis in a short period, and the patient died seven months after diagnosis. This report of a rapidly progressing and fatal adult poorly differentiated chordoma shows the highest Ki-67 labeling index reported to date. Prompt multidisciplinary treatment should be considered when the Ki-67 labeling index is high.

Inhalational Anesthesia Reduced Transient Neurological Events After Revascularization Surgery for Moyamoya Disease

BACKGROUND AND OBJECTIVES

The choice between inhalational and total intravenous anesthesia (TIVA) in revascularization surgery for Moyamoya disease (MMD) remains a topic of debate. Anesthesia methods have changed with the advent of new anesthetics. This study investigated whether modern anesthesia methods affected the development of neurological symptoms after revascularization surgery for MMD.

METHODS

This single-center retrospective study included 63 adult patients (82 hemispheres) with MMD treated with direct and indirect bypass surgeries at our hospital between 2013 and 2022. Patients were divided into inhalational anesthesia (IA) and TIVA groups based on the anesthesia maintenance method. Baseline patient characteristics; postoperative neurological symptoms, including hyperperfusion syndrome, cerebral infarction, and transient neurological events (TNEs); and cortical hyperintensity belt (CHB) sign scores (5-point scale from 0 to 4) on postoperative magnetic resonance imaging were compared between the two groups. The operation methods, anesthetics, and intraoperative hemodynamic and ventilatory parameters were compared between patients with and without TNEs.

RESULTS

The IA and TIVA groups comprised 39 and 43 hemispheres, respectively. The frequency of postoperative hyperperfusion syndrome and cerebral infarction did not differ between the groups, but the number of TNEs in the IA group (5/39; 13%) was significantly lower than that in the TIVA group (16/43; 37%). Multivariate logistic regression analysis revealed that TNEs were associated with TIVA (odds ratio, 3.91; 95% CI, 1.24-12.35; P = .02). The median [IQR] postoperative CHB sign score in the IA group (2 [1-3]) was significantly lower than that in the TIVA group (4 [3-4]).

CONCLUSION

The IA group had fewer postoperative TNEs and lower CHB sign scores than the TIVA group. Although further studies are needed, this study provides insights into the prevention of TNEs with IA and reconsideration of the optimal anesthesia for MMD.

Accelerating TOF-MRA: The impact of the combined use of compressed sensitivity encoding and spiral imaging

PURPOSE

To evaluate the image quality of the combined technique of compressed sensitivity encoding (CS) and spiral imaging in time-of-flight magnetic resonance angiography (TOF-MRA), which is approximately 2.5 times faster than conventional methods.

METHODS

Twenty volunteers underwent four TOF-MRA sequences: sensitivity encoding (SENSE) with acceleration factor of 4 (acquisition time: 4:55 min), CS with acceleration factor of 10.9, and spiral and CS-spiral (both 1:55 min). A quantitative image analysis (signal-to-noise ratio [SNR], contrast, and full width at half maximum [FWHM] edge criterion measurements) was performed on four TOF sequences. For qualitative image analysis, two board-certified radiologists evaluated the overall depiction of the proximal, intermediate, and distal branches in CS, spiral, and CS-spiral images using SENSE as a reference.

RESULTS

The SNR of BA in spiral and CS-spiral imaging was significantly lower than that in SENSE (p = 0.009). The contrasts of ACA and BA in CS-spiral were significantly higher and those in spiral were significantly lower than those in SENSE (p < 0.001). The FWHM in the CS image was significantly higher than that of SENSE; however, no significant differences were observed between the spiral or CS-spiral and SENSE. In qualitative analysis, the depiction of proximal vascular branches was significantly impaired in spiral than in others and that of distal vascular branches was significantly impaired in CS than in others (p < 0.001).

CONCLUSIONS

In TOF-MRA, which is approximately 2.5 times faster than conventional methods, the combined use of CS and spiral imaging demonstrated an improvement in image quality compared to either CS or spiral imaging alone.

SUMMARY STATEMENT

The image quality of Compressed SENSE and spiral imaging is particularly poor in the proximal and distal vascular branches, respectively at an extremely high acceleration factor; however, CS-spiral provided stable image quality in all regions as compared with the SENSE technique.

Feasibility study of super-resolution deep learning-based reconstruction using k-space data in brain diffusion-weighted images

PURPOSE

The purpose of this study is to evaluate the influence of super-resolution deep learning-based reconstruction (SR-DLR), which utilizes k-space data, on the quality of images and the quantitation of the apparent diffusion coefficient (ADC) for diffusion-weighted images (DWI) in brain magnetic resonance imaging (MRI).

METHODS

A retrospective analysis was performed on 34 patients who had undergone DWI using a 3 T MRI system with SR-DLR reconstruction based on k-space data in August 2022. DWI was reconstructed with SR-DLR (Matrix = 684 × 684) and without SR-DLR (Matrix = 228 × 228). Measurements were made of the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) in white matter (WM) and grey matter (GM), and the full width at half maximum (FWHM) of the septum pellucidum. Two radiologists assessed image noise, contrast, artifacts, blur, and the overall quality of three image types using a four-point scale. Quantitative and qualitative scores between images with and without SR-DLR were compared using the Wilcoxon signed-rank test.

RESULTS

Images with SR-DLR showed significantly higher SNRs and CNRs than those without SR-DLR (p < 0.001). No statistically significant variances were found in the apparent diffusion coefficients (ADCs) in WM and GM between images with and without SR-DLR (ADC in WM, p = 0.945; ADC in GM, p = 0.235). Moreover, the FWHM without SR-DLR was notably lower compared to that with SR-DLR (p < 0.001).

CONCLUSION

SR-DLR has the potential to augment the quality of DWI in DL MRI scans without significantly impacting ADC quantitation.

Simplified Transradial Access for Aneurysms Treatment: A Guiding System Using Solo Distal Access Catheter and Anatomical Considerations

OBJECTIVE

The recent shift from transfemoral access to transradial access in neurointervention has led to gaps in guiding systems. We propose a useful guiding system, the solo distal access catheter system without a conventional guiding catheter or a sheath in transradial access for aneurysms treatment. We also assessed the anatomical features required for suitable patient selection.

METHODS

We retrospectively collected data from consecutive patients with aneurysms treated with the solo distal access catheter system at our institution between April 2022 and April 2023, and evaluated the anatomical factors that appeared to affect the procedure.

RESULTS

Of the 20 patients who underwent transradial access, 11 were treated using the solo distal access catheter system, and 10 (90.9%) completed the procedure. No radial artery occlusion was detected. The entry angle of the target vessel ranged from 37° to 139°, and the mean proximal parent artery diameter was 9.34 ± 1.48 mm. A double subclavian innominate curve was observed in 3 of 5 patients whose target vessels were the right common carotid artery.

CONCLUSIONS

Using a solo distal access catheter as a guiding system for treating aneurysm proved effective and feasible with appropriate patient selection. Anatomical assessment of the entry angle of the target vessel, proximal parent artery diameter, and tortuosity may be important factors for the success of this method.

Intracranial aneurysms treated with stent-assisted coil embolization: evaluation with four-dimensional ultrashort-TE MR angiography

OBJECTIVES

As a novel follow-up method for intracranial aneurysms treated with stent-assisted coil embolization (SACE), we developed four-dimensional magnetic resonance angiography (MRA) with minimized acoustic noise utilizing ultrashort-echo time (4D mUTE-MRA). We aimed to assess whether 4D mUTE-MRA is useful for the evaluation of intracranial aneurysms treated with SACE.

METHODS

This study included 31 consecutive patients with intracranial aneurysm treated with SACE who underwent 4D mUTE-MRA at 3 T and digital subtraction angiography (DSA). For 4D mUTE-MRA, five dynamic MRA images with a spatial resolution of 0.5 × 0.5 × 0.5 mm3 were obtained every 200 ms. Two readers independently reviewed the 4D mUTE-MRA images to evaluate the aneurysm occlusion status (total occlusion, residual neck, and residual aneurysm) and the flow in the stent using a 4-point scale (from 1 [not visible] to 4 [excellent]). The interobserver and intermodality agreement was assessed using κ statistics.

RESULTS

On DSA images, 10 aneurysms were classified as total occlusion, 14 as residual neck, and 7 as residual aneurysm. In terms of aneurysm occlusion status, the intermodality and interobserver agreement was excellent (κ = 0.92 and κ = 0.96, respectively). For the flow in the stents on 4D mUTE-MRA, the mean score was significantly higher for single stents than multiple stents (p < .001) and for open-cell type stents than closed-cell type (p < .01).

CONCLUSIONS

4D mUTE-MRA is a useful tool with a high spatial and temporal resolution for the evaluation of intracranial aneurysms treated with SACE.

KEY POINTS

• In the evaluation of intracranial aneurysms treated with SACE on 4D mUTE-MRA and DSA, the intermodality and interobserver agreement in aneurysm occlusion status was excellent. • 4D mUTE-MRA shows good to excellent visualization of flow in the stents, especially for cases treated with a single or open-cell stent. • 4D mUTE-MRA can provide hemodynamic information related to embolized aneurysms and the distal arteries to stented parent arteries.

Wnt/β‑catenin signaling is a novel therapeutic target for tumor suppressor CYLD‑silenced glioblastoma cells

Tumor suppressor cylindromatosis (CYLD) dysfunction by its downregulation is significantly associated with poor prognosis in patients with glioblastoma (GBM), the most aggressive and malignant type of glioma. However, no effective treatment is currently available for patients with CYLD‑downregulated GBM. The aim of the present study was to identify the crucial cell signaling pathways and novel therapeutic targets for CYLD downregulation in GBM cells. CYLD knockdown in GBM cells induced GBM malignant characteristics, such as proliferation, metastasis, and GBM stem‑like cell (GSC) formation. Comprehensive proteomic analysis and RNA sequencing data from the tissues of patients with GBM revealed that Wnt/β‑catenin signaling was significantly activated by CYLD knockdown in patients with GBM. Furthermore, a Wnt/β‑catenin signaling inhibitor suppressed all CYLD knockdown‑induced malignant characteristics of GBM. Taken together, the results of the present study revealed that Wnt/β‑catenin signaling is responsible for CYLD silencing‑induced GBM malignancy; therefore, targeting Wnt/β‑catenin may be effective for the treatment of CYLD‑negative patients with GBM with poor prognosis.

Aneurysmal Inflow Rate Coefficient Predicts Ultra-early Rebleeding in Ruptured Intracranial Aneurysms: Preliminary Report of a Computational Fluid Dynamics Study

Rebleeding from a ruptured intracranial aneurysm has poor outcomes. Although numerous factors are associated with rebleeding, studies on computational fluid dynamics (CFD) on hemodynamic parameters associated with early rebleeding are scarce. In particular, no report of rebleeding in ultra-early phase exists. We aimed to elucidate the specific hemodynamic parameters associated with ultra-early rebleeding using CFD. In this study, the rebleeding group included patients with aneurysmal subarachnoid hemorrhage (aSAH) that rebled within 6 h from the onset. The control group included patients without rebleeding, observed for >10 h following the initial rupture. Clinical images after initial rupture and before rebleeding were used to build 3D vessel models for hemodynamic analysis focusing on the following parameters: time-averaged wall shear stress (WSS), normalized WSS, low shear area, oscillatory shear index, relative residence time, pressure loss coefficient, and aneurysmal inflow rate coefficient (AIRC). Five and 15 patients in the rebleeding and control groups, respectively, met the inclusion criteria. The World Federation of Neurosurgical Surgeons grade was significantly higher in the rebleeding group (p = 0.0088). Hemodynamic analysis showed significantly higher AIRC in the rebleeding group (p = 0.042). The other parameters were not significantly different between groups. There were no significant differences or correlations between SAH severity and AIRC. AIRC was identified as a hemodynamic parameter associated with ultra-early rebleeding of ruptured intracranial aneurysms. Thus, AIRC calculation may enable the prediction of ultra-early rebleeding.

Distinct patterns of copy number alterations may predict poor outcome in central nervous system germ cell tumors

We have previously reported that 12p gain may predict the presence of malignant components and poor prognosis for CNS germ cell tumor (GCT). Recently, 3p25.3 gain was identified as an independent predictor of poor prognosis for testicular GCT. Eighty-one CNS GCTs were analyzed. Copy number was calculated using methylation arrays. Five cases (6.2%) showed 3p25.3 gain, but only among the 40 non-germinomatous GCTs (NGGCTs) (5/40, 12.5%; p = 0.03). Among NGGCTs, those with a yolk sac tumor component showed a significantly higher frequency of 3p25.3 gain (18.2%) than those without (1.5%; p = 0.048). NGGCTs with gain showed significantly shorter progression-free survival (PFS) than those without (p = 0.047). The 3p25.3 gain and 12p gain were independent from each other. The combination of 3p25.3 gain and/or 12p gain was more frequent among NGGCTs with malignant components (69%) than among those without (29%; p = 0.02). Germinomas containing a higher number of copy number alterations showed shorter PFS than those with fewer (p = 0.03). Taken together, a finding of 3p25.3 gain may be a copy number alteration specific to NGGCTs and in combination with 12p gain could serve as a marker of negative prognosis or treatment resistance. Germinoma with frequent chromosomal instability may constitute an unfavorable subgroup.

Pretreatment with Clodronate Improved Neurological Function by Preventing Reduction of Posthemorrhagic Cerebral Blood Flow in Experimental Subarachnoid Hemorrhage

BACKGROUND

Brain perivascular macrophages (PVMs) are potential treatment targets for subarachnoid hemorrhage (SAH), and previous studies revealed that their depletion by clodronate (CLD) improved outcomes after experimental SAH. However, the underlying mechanisms are not well understood. Therefore, we investigated whether reducing PVMs by CLD pretreatment improves SAH prognosis by inhibiting posthemorrhagic impairment of cerebral blood flow (CBF).

METHODS

In total, 80 male Sprague-Dawley rats received an intracerebroventricular injection of the vehicle (liposomes) or CLD. Subsequently, the rats were categorized into the prechiasmatic saline injection (sham) and blood injection (SAH) groups after 72 h. We assessed its effects on weak and severe SAH, which were induced by 200- and 300-µL arterial blood injections, respectively. In addition, neurological function at 72 h and CBF changes from before the intervention to 5 min after were assessed in rats after sham/SAH induction as the primary and secondary end points, respectively.

RESULTS

CLD significantly reduced PVMs before SAH induction. Although pretreatment with CLD in the weak SAH group provided no additive effects on the primary end point, rats in the severe SAH group showed significant improvement in the rotarod test. In the severe SAH group, CLD inhibited acute reduction of CBF and tended to decrease hypoxia-inducible factor 1α expression. Furthermore, CLD reduced the number of PVMs in rats subjected to sham and SAH surgery, although no effects were observed in oxidative stress and inflammation.

CONCLUSIONS

Our study proposes that pretreatment with CLD-targeting PVMs can improve the prognosis of severe SAH through a candidate mechanism of inhibition of posthemorrhagic CBF reduction.

A Consideration of Optimal Head Position in Transsylvian Selective Amygdalohippocampectomy

Transsylvian selective amygdalohippocampectomy (TSA) is one of the predominant surgical options for drug-resistant mesial temporal lobe epilepsy. The purpose of this article is to highlight the unique features of TSA and determine the setting to perform safe and secure TSA with special reference to the optimal head position. TSA should be performed via a small surgical corridor in the temporal stem that contains functionally important fiber tracts, including the uncinate fasciculus, the inferior fronto-occipital fasciculus, and the optic radiation. Graphical simulations proposed that low-degree (<30°) head rotation had the advantage of sufficiently opening the surgical field in TSA and may help surgical procedures within the limited exposure of the medial temporal structures. Inspection of the surgical videos implied that the collapse of the inferior horn was prevented in low-degree rotation, probably because the deformation due to the brain shift was minimized in the medial temporal structures. A simulation also implied that chin-up position had the advantage of resecting the tail of the hippocampus in a straightforward manner. We suggest that the setting is optimized in TSA with low-degree rotation and chin-up head position.

A Case of Cavernous Sinus Dural Arteriovenous Fistula Draining Solely to the Superior Ophthalmic Vein with Normal Cerebral Venous Flow from the Superficial Middle Cerebral Vein to the Inferior Petrosal Sinus due to a Septum in the Cavernous Sinus

Objective

We report here an atypical case of cavernous sinus dural arteriovenous fistula (CSDAVF) with a septation that separates the cavernous sinus (CS) into two components, namely, normal cerebral venous drainage and shunted blood drainage into the superior ophthalmic vein (SOV) alone. The CSDAVF was successfully treated by selective transvenous embolization (TVE) through the septum with the trans-inferior petrosal sinus (IPS) approach.

Case Presentation

A 74-year-old woman presented with right exophthalmos and tinnitus on the right side. Neuroradiological examination showed CSDAVF mainly supplied by multiple feeders from the bilateral ascending pharyngeal artery and meningohypophyseal trunk with a shunted pouch located medial-dorsally to the right CS. Blood from the CSDAVF drained via the anterior component of the CS to the right SOV only. Normal cerebral venous blood from the right superficial middle cerebral vein drained through the dorsolateral component of the right CS into the right IPS. These findings suggest that a septal barrier exists between the outflow tract of the dural arteriovenous fistula and the normal cerebral venous outflow tract within the CS. The CSDAVF was successfully treated by selective TVE through the septum with the trans-IPS approach after detailed evaluation of 3D rotational angiography (3DRA) and MRA/MR venography (MRV) cross-sectional images. The patient's symptoms improved, and she was discharged uneventfully.

Conclusion

Septation within the CS can completely separate the drainage route of the CSDAVF from the normal cerebral drainage route. Successful catheterization to the shunted pouch through the septum with the IPS approach and selective embolization were possible with detailed evaluation of anatomy on MRA/MRV cross-sectional images and 3DRA images.

White Cord Syndrome After Cervical Laminoplasty in an 81-Year-Old Man

White cord syndrome (WCS) shows high intramedullary signaling in T2-weighted MRI with worsening motor nerve symptoms after cervical spinal decompression surgery. It has been reported in only 13 cases. An 81-year-old man had numbness, weakness, and impaired fine motor control in both upper limbs for the previous five years. C3, C4, C6, open-door laminoplasty, and C5 laminectomy were performed. Intraoperative transcranial motor evoked potential normalization by compound muscle action potential showed an 80% reduction in amplitude in the right abductor pollicis brevis and a 96% reduction in the right abductor hallucis. Tetraplegia occurred immediately after the operation. Magnetic resonance imaging (MRI) on the day after the operation showed intramedullary T2 high signals at the C4 and C5 levels. According to Brunnstrom's staging, the upper and lower right limbs and the lower left limb were at stage two, and the upper left limb was at stage three, six months after the operation. Thirteen cases of WCS have been reported in the literature. These were thought to be caused by reperfusion due to decompression.

Deep learning-based reconstruction can improve the image quality of low radiation dose head CT

OBJECTIVES

To evaluate the image quality of deep learning-based reconstruction (DLR), model-based (MBIR), and hybrid iterative reconstruction (HIR) algorithms for lower-dose (LD) unenhanced head CT and compare it with those of standard-dose (STD) HIR images.

METHODS

This retrospective study included 114 patients who underwent unenhanced head CT using the STD (n = 57) or LD (n = 57) protocol on a 320-row CT. STD images were reconstructed with HIR; LD images were reconstructed with HIR (LD-HIR), MBIR (LD-MBIR), and DLR (LD-DLR). The image noise, gray and white matter (GM-WM) contrast, and contrast-to-noise ratio (CNR) at the basal ganglia and posterior fossa levels were quantified. The noise magnitude, noise texture, GM-WM contrast, image sharpness, streak artifact, and subjective acceptability were independently scored by three radiologists (1 = worst, 5 = best). The lesion conspicuity of LD-HIR, LD-MBIR, and LD-DLR was ranked through side-by-side assessments (1 = worst, 3 = best). Reconstruction times of three algorithms were measured.

RESULTS

The effective dose of LD was 25% lower than that of STD. Lower image noise, higher GM-WM contrast, and higher CNR were observed in LD-DLR and LD-MBIR than those in STD (all, p ≤ 0.035). Compared with STD, the noise texture, image sharpness, and subjective acceptability were inferior for LD-MBIR and superior for LD-DLR (all, p < 0.001). The lesion conspicuity of LD-DLR (2.9 ± 0.2) was higher than that of HIR (1.2 ± 0.3) and MBIR (1.8 ± 0.4) (all, p < 0.001). Reconstruction times of HIR, MBIR, and DLR were 11 ± 1, 319 ± 17, and 24 ± 1 s, respectively.

CONCLUSION

DLR can enhance the image quality of head CT while preserving low radiation dose level and short reconstruction time.

KEY POINTS

• For unenhanced head CT, DLR reduced the image noise and improved the GM-WM contrast and lesion delineation without sacrificing the natural noise texture and image sharpness relative to HIR. • The subjective and objective image quality of DLR was better than that of HIR even at 25% reduced dose without considerably increasing the image reconstruction times (24 s vs. 11 s). • Despite the strong noise reduction and improved GM-WM contrast performance, MBIR degraded the noise texture, sharpness, and subjective acceptance with prolonged reconstruction times relative to HIR, potentially hampering its feasibility.

Olfactory hallucinations caused by an unruptured posterior communicating artery aneurysm improved by clipping: A case report with literature review

Background

Unruptured cerebral aneurysms that lead to epilepsy are rare and olfactory hallucinations caused by such an aneurysm are extremely rare. Various treatments have been proposed, including wrapping, clipping with or without cortical resection, and coil embolization, but there is no consensus on the best approach.

Case Description

We present a case of a 69-year-old female who experienced olfactory hallucinations caused by a posterior communicating artery aneurysm and was treated with clipping without cortical resection, with a positive outcome.

Conclusion

According to our knowledge, there has been only one report of a posterior communicating artery aneurysm presenting with olfactory hallucinations has been reported, where clipping and cortical resection were performed. This is the first report of a posterior communicating artery aneurysm with olfactory hallucinations that was effectively treated with clipping alone. There have been a few similar reports of large middle cerebral artery aneurysms, most of which are believed to be caused by entorhinal cortex compression. Although a definitive treatment protocol for this condition remains elusive, we suggest that elimination of the pulsatile compressive stress exerted on the cerebral cortex through surgical clipping or coil embolization is crucial for achieving efficacious seizure management.

Lynch syndrome-associated chordoma with high tumor mutational burden and significant response to immune checkpoint inhibitors

Chordoma is a rare malignant bone tumor arising from notochordal tissue. Conventional treatments, such as radical resection and high-dose irradiation, frequently fail to control the tumor, resulting in recurrence and re-growth. In this study, genetic analysis of the tumor in a 72-year-old male patient with refractory conventional chordoma of the skull base revealed a high tumor mutational burden (TMB) and mutations in the MSH6 and MLH1 genes, which are found in Lynch syndrome. The patient and his family had a dense cancer history, and subsequent germline genetic testing revealed Lynch syndrome. This is the first report of a chordoma that has been genetically proven to be Lynch syndrome. Chordomas usually have low TMB; however, this is an unusual case, because the TMB was high, and immune checkpoint inhibitors effectively controlled the tumor. This case provides a basis for determining the indications for immunotherapy of chordoma based on the genetic analysis. Therefore, further extensive genetic analysis in the future will help to stratify the treatment of chordoma.

Two children with lymphocytic hypophysitis presenting with positive anti-rabphilin-3A antibody

Lymphocytic hypophysitis (LYH) is a rare chronic inflammatory disease characterized by lymphocytic infiltration of the anterior or posterior pituitary gland and hypothalamus. LYH is subdivided into lymphocytic adenohypophysitis (LAH), lymphocytic infundibulo-neurohypophysitis (LINH), and lymphocytic panhypophysitis (LPH) depending on the primary site. Most cases occur in adults, with few cases reported in children, and it is especially important to distinguish LYH from suprasellar malignancies, such as germ cell tumors and other neoplastic diseases. Although a biopsy is necessary for definitive diagnosis, it is desirable to be able to diagnose the disease without biopsy if possible, especially in children, because of the surgical invasiveness of the procedure. Recently, serum anti-rabphilin-3A antibodies have attracted attention as diagnostic markers for LYH, especially in LINH, but there are only a few reports on pediatric patients. In the present study, we experienced two children with LPH and LAH, respectively, who tested positive for anti-rabphilin-3A antibodies. This is the first report of children with LYH other than LINH positive for anti-rabphilin-3A antibodies, and anti-rabphilin-3A antibodies may be a useful non-invasive diagnostic marker not only for LINH but also for LYH in general. We also discuss the sensitivity and specificity of anti-rabphilin-3A antibody testing in cases where histological diagnosis has been made.

Clinicopathologic analysis of pineal parenchymal tumors of intermediate differentiation: a multi-institutional cohort study by the Kyushu Neuro-Oncology Study Group

PURPOSE

Pineal parenchymal tumors of intermediate differentiation (PPTIDs), which were recognized in the 2007 World Health Organization (WHO) classification, are rare, accounting for less than 1% of all central nervous system tumors. This rarity and novelty complicate the diagnosis and treatments of PPTID. We therefore aimed to evaluate the clinicopathological significance of this tumor.

METHODS

At 11 institutions participating in the Kyushu Neuro-Oncology Study Group, data for patients diagnosed with PPTID were collected. Central pathology review and KBTBD4 mutation analysis were applied to attain the diagnostically accurate cohort.

RESULTS

PPTID was officially diagnosed in 28 patients: 11 (39%) with WHO grade 2 and 17 (61%) with WHO grade 3 tumors. Median age was 49 years, and the male:female ratio was 1:2.1. Surgery was attempted in all 28 patients, and gross total resection (GTR) was achieved in 46% (13/28). Adjuvant radiotherapy and chemotherapy were administered to, respectively, 82% (23/28) and 46% (13/28). The 5-year progression-free survival (PFS) and overall survival rates were 64.9% and 70.4% respectively. Female sex (p = 0.018) and GTR (p < 0.01) were found to be independent prognostic factors for PFS and female sex (p = 0.019) was that for OS. Initial and second recurrences were most often leptomeningeal (67% and 100% respectively). 80% (20/25) of patients harbored a KBTBD4 mutation.

CONCLUSIONS

Female sex and GTR were independent prognostic factors in our patients with PPTID. Leptomeningeal recurrence was observed to be particularly characteristic of this tumor. The rate of KBTBD4 mutation observed in our cohort was acceptable and this could prove the accuracy of our PPTID cohort.

Macrophage colony-stimulating factor potentially induces recruitment and maturation of macrophages in recurrent pituitary neuroendocrine tumors

Although pituitary neuroendocrine tumors (PitNETs) are usually benign, some are highly invasive and recurrent. Recurrent PitNETs are often treatment-resistant and there is currently no effective evidence-based treatment. Tumor-associated macrophages (TAMs) promote tumor growth in many cancers, but the effect of TAMs on PitNETs remains unclear. This study investigated the role of TAMs in the incidence of recurrent PitNETs. Immunohistochemical analysis revealed that the densities of CD163- and CD204-positive TAMs tended to increase in recurrent PitNETs. Compared with TAMs in primary lesions, those in recurrent lesions were enlarged. To clarify the cell-cell interactions between TAMs and PitNETs, in vitro experiments were performed using a mouse PitNET cell line AtT20 and the mouse macrophage cell line J774. Several cytokines related to macrophage chemotaxis and differentiation, such as M-CSF, were elevated significantly by stimulation with macrophage conditioned medium. When M-CSF immunohistochemistry analysis was performed using human PitNET samples, M-CSF expression increased significantly in recurrent lesions compared with primary lesions. Although no M-CSF receptor (M-CSFR) expression was observed in tumor cells of primary and recurrent PitNETs, flow cytometric analysis revealed that the mouse PitNET cell line expressed M-CSFR. Cellular proliferation in mouse PitNETs was inhibited by high concentrations of M-CSFR inhibitors, suggesting that cell-to-cell communication between PitNETs and macrophages induces M-CSF expression, which in turn enhances TAM chemotaxis and maturation in the tumor microenvironment. Blocking the M-CSFR signaling pathway might be a novel therapeutic adjuvant in treating recurrent PitNETs.

An epileptogenic intracranial cystic lesion lined with fallopian tube-type epithelium: illustrative case

BACKGROUND

Intracranial cystic lesions are often a trigger for epileptic seizures. However, there has never been a report of a cystic lesion lined with fallopian tube-type epithelium.

OBSERVATIONS

A 48-year-old female presented with a cystic lesion in the right occipital lobe, which gradually grew over 8 years. Right occipital lobe epilepsy was diagnosed based on visual aura, convulsive seizures, and electroencephalogram findings and the cyst was surgically removed. Further examination revealed the cyst was lined with ciliated cells, which had morphological and immunohistochemical features similar to those of fallopian tube epithelium.

LESSONS

The characteristics of the cyst did not conform to any known types of benign cystic lesion. To the authors' knowledge, no such cyst has been reported before. The authors discuss the origins and pathogenesis of this unfamiliar cystic lesion.

Safety and efficacy of tumour-treating fields (TTFields) therapy for newly diagnosed glioblastoma in Japanese patients using the Novo-TTF System: a prospective post-approval study

BACKGROUND

Tumour-treating fields therapy is a locoregional, anti-cancer treatment. Efficacy and safety of tumour-treating fields therapy in adults with newly diagnosed glioblastoma were demonstrated in the pivotal phase 3 EF-14 study (NCT00916409). Here, we report post-approval data of tumour-treating fields therapy in Japanese patients with newly diagnosed glioblastoma.

METHODS

Unsolicited post-marketing surveillance data from Japanese patients with newly diagnosed glioblastoma treated with tumour-treating fields therapy (December 2016-June 2020) were retrospectively analysed. The primary endpoints were skin, neurological and psychiatric adverse events. The secondary endpoints were 1- and 2-year overall survival rates, and the 6-month progression-free survival. adverse events were analysed using MedDRA v24.0. The overall survival and progression-free survival were assessed using the Kaplan-Meier survival analysis (log-rank testing). The Cox proportional hazard regression analyses were also performed.

RESULTS

Forty patients with newly diagnosed glioblastoma were enrolled (62.5% male; median age 59 years; median baseline Karnofsky Performance Scale score 90). The most common tumour-treating-fields-therapy-related adverse event was beneath-array local skin reaction (60% of patients). The adverse events were mostly mild to moderate in severity. Neurological disorders were observed in 2.5% patients (one patient reported dysesthesia). No psychiatric disorders were reported. The 1- and 2-year overall survival rates were 77.9% (95% CI 60.6-88.3) and 53.6% (35.5-68.7%), respectively. The 6-month progression-free survival was 77.5% (61.2-87.6%). These survival rates compare favourably with those in the EF-14 trial (1- and 2-year overall survival rates: 73% [69-77%] and 43% [39-48%], respectively; 6-month progression-free survival rate: 56% (51-61%).

CONCLUSION

This post-approval, real-world evidence study revealed no new safety signals and suggests the safety and efficacy of tumour-treating fields therapy in Japanese patients with newly diagnosed glioblastoma.

Morphologically, genetically and spatially mixed astrocytoma and oligodendroglioma; chronological acquisition of 1p/19q codeletion and CDKN2A deletion: a case report

"Oligoastrocytoma" disappeared as of the revised fourth edition of the World Health Organization Classification of Tumours of the Central Nervous System, except where appended with "not otherwise specified (NOS)". However, histopathological and genetic backgrounds of cases with dual features of astrocytoma/oligodendroglioma have been sparsely reported. We encountered a 54-year-old man with right frontal glioma comprising two distinct parts on imaging and histopathological examination: grade 4 astrocytoma with IDH1-R132H, ATRX loss, p53-positivity and intact 1p/19q; and oligodendroglioma with IDH1-R132H, intact ATRX, p53-negativity and partially deleted 1p/19q. At recurrence, histopathology showed low-grade mixed astrocytic and oligodendroglial features: the former with IDH1-R132H, ATRX loss, p53-positivity and intact 1p/19q and the latter showing IDH1-R132H, intact ATRX, p53-negativity and 1p/19q codeletion. At second recurrence, histopathology was astrocytoma grade 4 with IDH1-R132H, ATRX loss, p53-positivity and intact 1p/19q. Notably, 1p/19q codeletion was acquired at recurrence and CDKN2A was deleted at second recurrence. These findings suggest insights into tumorigenesis: (1) gliomas with two distinct lineages might mix to produce "oligoastrocytoma"; and (2) 1p/19q codeletion and CDKN2A deletion might be acquired during chemo-radiotherapy. Ultimately, astrocytic and oligodendroglial clones might co-exist developmentally or these two lineages might share a common cell-of-origin, with IDH1-R132H as the shared molecular feature.

Two weeks administration of tranexamic acid for acute intracerebral hemorrhage: A hospital-based pilot study

Background

A previous report suggested that functional status does not differ between patients who received tranexamic acid and those who received placebo within the early hours of intracerebral hemorrhage (ICH). Our pilot study tested the hypothesis that 2 weeks administration of tranexamic acid would contribute to functional improvement.

Methods

Consecutive patients with ICH were administered 250 mg tranexamic acid 3 times a day continuously for 2 weeks. We also enrolled historical control consecutive patients. We collected clinical data that involved hematoma size, level of consciousness, and Modified Rankin Scale (mRS) scores.

Results

Univariate analysis showed that the mRS score on day 90 was better in the administration group (P = 0.0095). The mRS scores on the day of death or discharge suggested a favorable effect of the treatment (P = 0.0678). Multivariable logistic regression analysis also showed that the treatment was associated with good mRS scores on day 90 (odds ratio [OR] = 2.81, 95% confidence interval [CI]: 1.10-7.21, P = 0.0312). In contrast, ICH size was associated with poor mRS scores on day 90 (OR = 0.92, 95% CI: 0.88-0.97, P = 0.0005). After propensity score matching, there was no difference in the outcomes between the two groups. We did not detect mild and serious adverse events.

Conclusion

The study could not show the significant effect of 2 weeks administration of tranexamic acid on functional outcomes of ICH patients after the matching; however, suggested that this treatment is at least safe and feasible. A larger and adequately powered trial is needed.

BT-5 LONG-TERM OUTCOME OF CLIVAL CHORDOMAS AT A SINGLE INSTITUTION

Purpose

Chordoma is a rare malignant tumor, about 30% of which occurs in the clivus. The purpose of this study is to investigate the outcome after treatment of clival chordoma in our institute.

Methods

Nineteen patients {M/F=11/8, mean age: 50.4 (15-72) years} who were treated between 1987 and 2021 and followed for at least 6 months were retrospectively evaluated for survival and local control rate.

Results

The cumulative survival rate was 89.2% at 5 years, 82.3% at 10 years, and 54.9% at 25 years, and the median OS was 107 (6-359) months. 4 deaths: 2 tumor deaths (1 from poorly differentiated chordoma), 2 non-tumor deaths (1 from IC rupture after heavy ion radiotherapy). The cumulative local control rate was 47.3% at 5 years and 35.5% at 10 years, with a median progression-free survival (PFS) of 41 (0-278) months. There was no difference in OS (p=0.85) or PFS (p=0.90) between the two groups, with 6 cases of gross total resection, GTR (all transsphenoidal) and 13 cases of non-GTR (9 transsphenoidal, 4 transcranial) at first surgery. In the 4 patients without irradiation (1 GTR, 3 non-GTR), no disease progression (PD) was observed, and the mean OS was 170 (69-278) months. Of the 15 patients irradiated, 6 were irradiated before PD and 9 were irradiated after PD, and there was no difference in OS or PFS between the two groups, i.e., the timing of irradiation. One patient with refractory chordoma was found to have elevated TMB levels by cancer genome testing and is currently receiving pembrolizumab, which has resulted in significant tumor shrinkage.

Conclusion

The patients with clival chordoma have a varied course, which may be due to differences in molecular biology. Cancer genome testing may provide new treatment options, such as molecularly targeted drugs and immune checkpoint inhibitors, for refractory cases.

PEDT-10 PHASE II TRIAL OF PATHOLOGY-BASED THREE-GROUP TREATMENT STRATIFICATION FOR PATIENTS WITH CNS GERM CELL TUMORS: A LONG-TERM FOLLOW-UP STUDY

Background

Phase II clinical trial funded by Ministry of Health, Labour and Welfare from 1995 to 2003 evaluated efficacy of pathology-based three-group treatment stratification for CNS germ cell tumors (GCTs). We here present long-term follow-up results.

Methods

Total 228 cases were registered. Germinoma was treated with carboplatin+etoposide (CARE) and extended-local irradiation, local irradiation was added for intermediate-prognosis-group, and poor-prognosis-group was treated with ifosfamide+cisplatin+etoposide (ICE) and whole-brain or craniospinal irradiation.

Results

Mean/median ages at diagnosis were 16.8/16 years and female-to-male ratio was 40-188. Registry included 123 germinomas, 76 intermediate-prognosis-group cases (including 38 germinoma with STGC), 28 poor-prognosis-group cases and 1 mature teratoma. Median 222-months follow-up was conducted, and 56 recurrences and 39 deaths were recorded. 10 and 20-year recurrence-free survival (RFS) for germinoma, intermediate and poor-prognosis-groups were 84/79%, 83/76% and 59/59%, respectively, and overall survival (OS) for each were 97/91%, 92/85% and 57/53%, respectively. Prognosis for germinoma with or without STGC was the same. Basal ganglia germinoma showed significantly shorter RFS but OS was not different from other locations. Median age at death was 24 years, and ages were significantly different depending on causes, such as disease-related (14 years on average) and complications (29 years). OS after recurrence at 5/10/20 years were 64/62/48%.Hormonal supplementation was seen in 82% for neurohypophyseal cases and antidiuretic hormone supplementation was most frequent (82%). Among available cases, 20-out-of-155 cases showed neoplastic/vascular complications, among which cavernous malformation was the most (n=9). Median period until complication presentation was 235 months, and the rate at 20 years was 11%.

Conclusions

Germinoma and intermediate-prognosis-group cases showed long-term survival for approximately 90%, while more intensive treatment would be necessitated for poor-prognosis-group. Long-term survivors often required hormonal supplementation, and increasing frequency of treatment-related complications was observed. There is no end of outpatient follow-up for CNS GCT patients.

[Dystrophia myotonica Type 1 associated with glioblastoma: a case report]

This case involved a 65-year-old woman, who had been suffered from weakness in both legs for 10 years. She had not been diagnosed of dystrophia myotonica type 1 (DM1) despite her son's diagnosis of DM and her distinct facial features and gait anomaly. During her son's recent clinical visit, she was finally suspected of having DM. She was sent to our institution, where a distinct muscle atrophy and grip myotonia were observed and a genetical examination was performed. The sequencing data confirmed her diagnosis of DM1 due to the distinct 230-900 CTG repeats found in the dystrophia myotonica protein kinase gene 3' untranslated region. A brain MRI revealed an abnormal lesion with irregular ring-enhancement at the right temporal lobe. Because of the steady growth of the lesion during one month observation, a surgical intervention was performed in our institution. The histopathological examination gave a diagnosis of glioblastoma multiforme (GBM). The clinical management of the patient required special cares during the perioperative periods due to the distinct pathological manifestation of DM. The risk of developing cancer in DM patients has been estimated about twice as much as general population. Since GBM developed in the DM patient is rarely reported, we present this rare case with a few insights: the difficulties of the clinical management of DM patients under the perioperative stress; the pathological contribution of DM to the malignant transformation of the glial cells.

Bevacizumab beyond Progression for Newly Diagnosed Glioblastoma (BIOMARK): Phase II Safety, Efficacy and Biomarker Study

We evaluated the efficacy and safety of bevacizumab beyond progression (BBP) in Japanese patients with newly diagnosed glioblastoma and explored predictors of response to bevacizumab. This phase II study evaluated a protocol-defined primary therapy by radiotherapy with concurrent and adjuvant temozolomide plus bevacizumab, followed by bevacizumab monotherapy, and secondary therapy (BBP: bevacizumab upon progression). Ninety patients received the protocol-defined primary therapy (BBP group, n = 25). Median overall survival (mOS) and median progression-free survival (mPFS) were 25.0 and 14.9 months, respectively. In the BBP group, in which O⁶-methylguanine-DNA methyltransferase (MGMT)-unmethylated tumors predominated, mOS and mPFS were 5.8 and 1.9 months from BBP initiation and 16.8 and 11.4 months from the initial diagnosis, respectively. The primary endpoint, the 2-year survival rate of the BBP group, was 27.0% and was unmet. No unexpected adverse events occurred. Expression profiling using RNA sequencing identified that Cluster 2, which was enriched with the genes involved in macrophage or microglia activation, was associated with longer OS and PFS independent of the MGMT methylation status. Cluster 2 was identified as a significantly favorable independent predictor for PFS, along with younger age and methylated MGMT. The novel expression classifier may predict the prognosis of glioblastoma patients treated with bevacizumab.

Primary Intracranial Spindle Cell Sarcoma, DICER1-Mutant, with MDM2 Amplification Diagnosed on the Basis of Extensive Molecular Profiling

Primary intracranial spindle cell sarcoma is an extremely rare mesenchymal tumor, the molecular pathogenesis of which is poorly understood. Because of the lack of specific markers, diagnosis sometimes relies on ruling out all possible differential diagnoses, often making it difficult to reach a definitive diagnosis. In this case study, we report a 69 year-old female patient for whom the integration of multi-layered molecular analyses contributed to making the diagnosis. The disease exhibited aggressive clinical behavior, requiring two sequential surgeries because of rapid regrowth within a short period. Primary and recurrent tumors exhibited similar histological features, in which spindle-shaped cells arranged in interlacing fascicles without any specific architectures, implicating sarcomatous tumors. In immunohistochemistry testing, tumor cells were immunopositive for vimentin but lacked any specific findings that contribute to narrowing down the differential diagnoses. Seeking further diagnostic clues, we performed DNA methylation-based analysis. The copy number analysis revealed MDM2 gene amplification and loss of heterozygosity of 22q. Moreover, dimension reduction clustering analysis implicated a methylation pattern comparable to aggressive types of sarcomas. In addition, an in-house next-generation sequencing panel ("Todai-OncoPanel") analysis identified somatic mutations in DICER1, NF2, and ATRX genes. Taken all together, we finally made the diagnosis of primary intracranial spindle cell sarcoma, DICER1-mutant, with MDM2 gene amplification. This case report suggests that even for the tumors with insufficient morphological and immuno-histological diagnostic clues, integration of multi-layered molecular analyses can contribute to making the diagnoses as well as to understanding the rare tumors by elucidating unexpected genetic and epigenetic features.

Whole Tumor Radiomics Analysis for Risk Factors Associated With Rapid Growth of Vestibular Schwannoma in Contrast-Enhanced T1-Weighted Images

OBJECTIVE

To investigate the features associated with rapid growth of vestibular schwannoma using radiomics analysis on magnetic resonance imaging (MRI) together with clinical factors.

METHODS

From August 2005 to February 2019, 67 patients with vestibular schwannoma underwent contrast-enhanced T1-weighted MRI at least twice as part of their diagnosis. After excluding 3 cases with an extremely short follow-up period of 15 days or less, 64 patients were finally enrolled in this study. Ninety-three texture features were extracted from the tumor image data using 3D Slicer software (http://www.slicer.org/). We determined the texture features that significantly affected maximal tumor diameter growth of more than 2 mm/year using Random Forest and Bounty. We also analyzed age and tumor size as clinical factors. We calculated the areas under the curve (AUCs) using receiver operating characteristic analysis for prediction models using texture, clinical, and mixed factors by Random Forest and 5-fold cross-validation.

RESULTS

Two texture features, low minimum signal and high inverse difference moment normalized (Idmn), were significantly associated with rapid growth of vestibular schwannoma. The mixed model of texture features and clinical factors offered the highest AUC (0.69), followed by the pure texture (0.67), and pure clinical (0.63) models. The minimum signal was the most important variable followed by tumor size, Idmn, and age.

CONCLUSIONS

Our radiomics analysis found that texture features were significantly associated with the rapid growth of vestibular schwannoma in contrast-enhanced T1-weighted images. The mixed model offered a higher diagnostic performance than the pure texture or clinical models.

Variations in the branching patterns of the anterior choroidal artery: an angiographic study with special reference to temporal lobe epilepsy surgery

BACKGROUND

The preservation of the anterior choroidal artery (AChA) is essential for avoiding neurological sequelae after mesial temporal lobe epilepsy (mTLE) surgery. The purpose of this study is to reveal the anatomical variation in which the perforating branches arise from the plexal segment of the AChA by using a modern neuroimaging modality.

METHODS

This study analyzed 3D rotational angiography (3DRA) images from 56 subjects. The AChA and perforating branches were visualized using slab MIP. We analyzed branching patterns, courses of the perforating arteries arising from the plexal segment of the AChA, and the anastomosis of the AChA with other cerebral arteries.

RESULTS

The slab MIP applied to 3DRA visualized one or more perforating branches from the AChA in 92.9% of cases. The presence of perforating branches arising from the AChA plexal segment was 17.3%. Most of the branching points of plexal perforators were likely located in the operative field during hippocampal resection. The course of the AChA plexal perforators included the posterior limb of the internal capsule. Anastomosis with other cerebral arteries was visualized in 25% of the AChA with plexal perforators.

CONCLUSIONS

3DRA slab MIP was useful for visualizing the perforating branches of the AChA. Our results showed the possibility that surgical manipulation of the choroid plexus may cause infarction in the AChA territory. We suggest that the existence of the AChA plexal perforators should be recognized to further enhance the safety of hippocampal resection for mTLE.

EPEN-27. Epigenetic dissection of spinal ependymomas (SP-EPN) separates tumors with and withoutNF2 mutation

Ependymomas encompass multiple, clinically relevant tumor types based on localization, genetic alterations, and epigenetic and transcriptomic profiles. Tumors belonging to the methylation class of spinal ependymoma (SP-EPN) represent the most common intramedullary neoplasms in children and adults. However, molecular data of SP-EPN are scarce, and clear treatment recommendations are lacking. The only known recurrent genetic events in SP-EPN are loss of chromosome 22q and NF2 mutations. Yet, it remains unclear whether SP-EPN with germline or sporadic NF2 mutations or with NF2 wild type status differ clinically or molecularly. To provide a comprehensive molecular profile of SP-EPN, we integrated epigenetic, genomic, transcriptomic, and histological analyses of up to 237 cases. Clustering of methylation data revealed two distinct molecular SP-EPN subtypes. The distribution of NF2 mutated cases differed significantly across these subtypes (p <0.0001): The vast majority of tumors harboring either a previously known NF2 germline mutation or a sporadic mutation were assigned to subtypes A, whereas subtype B tumors mainly contained NF2 wild type sequences. In addition, subtype A tumors showed a lower frequency of MGMT promoter methylation (p= 0.018) and contained almost all pediatric patients of the cohort. Whole-exome sequencing (30 cases) identified numerous mutations in NF2 wild type and mutated tumors. Mutated genes in NF2 wild type tumors were enriched for genes associated with cell cycle and cytoskeleton. RNA sequencing revealed two distinct transcriptional groups with upregulation of proliferative genes in one group and upregulation of cilial genes in the other group. The molecular subtypes displayed subtle, but significant differences in the appearance of histopathological characteristics, such as surfaces, inflammation, and hyalinized vessels. Investigation of clinical parameters is ongoing and will complete the picture of SP-EPN heterogeneity as an important basis for future clinical decision-making.

A phase II, multicenter, single-arm trial of eribulin in patients with bevacizumab-resistant recurrent glioblastoma

2036

Background: Glioblastoma (GBM) is one of the worst prognostic cancers and there is no effective treatment after failure of bevacizumab. Eribulin is a microtubule inhibitor used for the treatment of patients with metastatic breast cancer and liposarcoma. We previously reported that eribulin strongly inhibits the RNA-dependent RNA polymerase (RdRP) activity of TERT protein in cancer cells, and has a strong anti-tumor effect against GBM cells with TERT promoter mutation. In this study we aim to investigate the efficacy and safety of eribulin in patients with bevacizumab-resistant recurrent GBM. Methods: This is an open-label, multicenter, single-arm phase II trial. Eligible patients aged 20-75 years with bevacizumab-resistant recurrent GBM were enrolled from 2018-2020. Patients received eribulin 1.4 mg/m2 on days 1 and 8 of 21-day cycle until disease progression or intolerable toxicity was observed. The primary endpoint was one-year overall survival rate (1yOS%). The 35 patients are needed to achieve an 80% power at a one-sided alpha of 10%, under threshold 1yOS% of 10% and expected 1yOS% of 25%. Results: Thirty-seven patients aged 26-73 (median: 54) years were treated. Twenty-six of 37 (70.3%) patients were diagnosed as IDH-wildtype GBM, 4 (10.8%) were with IDH-mutant GBM and 7 (18.9%) were GBM, NOS. Thirty-four (91.9%) patients had a Karnofsky performance status of 70 or 80 at the registration. Thirty-one (83.8%) patients received additional treatments, including 28 (75.7%) bevacizumab, 11 (29.7%) re-irradiation and 3 (8.1%) resection after failure of eribulin. Among 37 subjects, 32 surgical specimens were analyzed for TERT promoter mutation and 15 for RdRP activity. 1yOS% was 29.7% [80% CI: 20.5 to 39.5 (p < 0.0001), 95% CI: 16.1 to 44.6]. Median OS was 9.0 months [95% CI: 6.2 to 11.0] and median progression-free survival was 1.5 months [95% CI: 1.4 to 1.7]. Neither TERT nor RdRP statuses was associated with prolonged OS. Among all the target lesions evaluated, two lesions decreased more than 50% in size and the patients survived more than one year, however no obvious PR was confirmed at the final evaluation. The disease control rate was 25.7% [95% CI: 12.5 to 43.3]. Common ≥ grade 2 AEs were neutropenia (70.3%), leukopenia (56.8%), lymphopenia (27.0%), elevation of γ-GTP (13.5%), elevation of ALT (10.8%), elevation of AST (8.1%), alopecia (8.1%). Treatment-related grade 3 or 4 AEs occurred in 59.5% of subjects. There were no AEs leading to death. Conclusions: Eribulin was safely applied for the patients with recurrent GBM. This phase II study met its primary endpoint of 1yOS%, although no obvious response was observed. Further investigation to reveal the biomarkers related to longer survival is underway. Clinical trial information: UMIN000030359.

Prognostic Factors and Histopathological Features of Pediatric Intracranial Ependymomas: Nationwide Brain Tumor Registry-based Study of Japan

To assess the clinicopathological features and prognostic factors of pediatric intracranial ependymomas and to explore the current diagnostic practice, we analyzed clinical data from the Brain Tumor Registry of Japan (BTRJ). Data of fifty children under 18 years of age diagnosed with intracranial ependymoma were extracted from the BTRJ database. Cases were reviewed for overall survival (OS) and progression-free survival (PFS), with attention to gender, preoperative Karnofsky performance status score, location of the tumor, the extent of resection, World Health Organization (WHO) histopathological grading, and adjuvant therapy. The median age at diagnosis was 6.1 years, ranging from 7 months to 17.6 years. Based on the WHO histopathological grading, 27 patients were classified under grade 2 (54%) and 23 patients were classified under grade 3 (46%). Gross total resection (GTR) was achieved in 30 patients (60%). The median follow-up time was 65 months. Five-year PFS and OS were 47.2 ± 7.3% and 73.3 ± 6.7%, respectively. GTR was associated with longer OS (P = 0.02). The histopathological grading was not an independent prognostic factor for the OS. Mitosis and microvascular proliferation were higher among patients with grade 3 than in those with grade 2, which aided in deciding the WHO grade. This nationwide study revealed the characteristics and outcomes of patients with childhood ependymomas. GTR was the factor most consistently associated with improved survival. In contrast, the histopathological grading in this cohort was not a significant prognostic factor. More reproducible and practical criteria for the diagnosis of intracranial ependymomas should be further pursued in future studies.

Ribosomal proteins induce stem cell-like characteristics in glioma cells as an "extra-ribosomal function"

The characteristic features of plasticity and heterogeneity in glioblastoma (GB) cells cause therapeutic difficulties. GB cells are exposed to various stimuli from the tumor microenvironment and acquire the potential to resist chemoradiotherapy. To investigate how GB cells acquire stem cell-like phenotypes, we focused on ribosomal proteins, because ribosome incorporation has been reported to induce stem cell-like phenotypes in somatic cells. Furthermore, dysregulation of ribosome biogenesis has been reported in several types of cancer. We focused on ribosomal protein S6, which promotes sphere-forming ability and stem cell marker expression in GB cells. We expect that investigation of dysregulation of ribosome biogenesis and extra-ribosomal function in GB will provide new insights about the plasticity, heterogeneity, and therapeutic resistance of GB cells, which can potentially lead to revolutionary therapeutic strategies.

A case of subarachnoid hemorrhage caused by multiple cerebral aneurysms due to segmental arterial mediolysis

Background:

Segmental arterial mediolysis (SAM) is a condition in which an aneurysm is formed by causing lysis of the media and remodeling of blood vessels. Short-term recurrence has been reported in abdominal aortic aneurysms. Cerebral aneurysms have been suggested to form in a short period not only in the abdominal cavity but also in the intracranial arteries in SAM.

Case Description:

A 36-year-old pregnant woman at 35 weeks’ gestation developed sudden headache and disorientation. Head magnetic resonance imaging showed a small amount of subarachnoid hemorrhage in the right ambient cistern. A fusiform cerebral aneurysm was found in the periphery of the right superior cerebellar artery, and small saccular aneurysms were found in the periphery of the right posterior cerebral artery and left posterior inferior cerebral artery. After delivery of the fetus, endovascular embolization of the ruptured aneurysm was performed. However, 10-week postoperatively, she developed sudden headache. Hemorrhage was found in the fourth ventricle, and enlargement of the left posterior inferior cerebellar artery (PICA) peripheral aneurysm and disappearance of the right posterior cerebral artery peripheral aneurysm were confirmed. A ruptured aneurysm in the peripheral left PICA was removed after trapping. Intraoperatively, an unruptured thrombosed aneurysm that was not visualized by imaging was also removed. Histopathological examination showed no calcification or inflammation, rupture of the internal elastic lamina, and lack of segmentation, and SAM was diagnosed.

Conclusion:

In atypical dissecting aneurysms, SAM should be considered as a differential diagnosis. Systemic examination and short-term follow-up are also necessary.

Rectal cancer diagnosed after resection of isolated brain metastasis

Background

Brain metastasis of colorectal cancer is infrequent, and isolated brain metastases are more infrequent. Thus, when neurological symptoms, such as paralysis or disturbance of consciousness appear, there is a high probability that the cancer has spread to other organs.

Case presentation

Here, we present a 64-year-old man with a progressive headache, decreased motivation, and aphasia who was diagnosed with a brain tumor in the left frontal region. He underwent a craniotomy, and the brain tumor was diagnosed as adenocarcinoma. We performed a colonoscopy and diagnosed rectal cancer without other distant metastases. After whole-brain radiotherapy (WBRT), low anterior resection for primary rectal tumor was performed using a robotic system. The patient was discharged in good condition and received postoperative adjuvant therapy for rectal cancer. He showed no signs of recurrence after 1 year of follow-up.

Conclusions

We described a rare case of rectal cancer that was diagnosed after resection of isolated brain metastasis. A good prognosis was achieved with surgery and WBRT.

Blocking cholesterol efflux mechanism is a potential target for anti-lymphoma therapy

Cholesterol is an essential plasma membrane lipid for the maintenance of cellular homeostasis and cancer cell proliferation. Free cholesterol is harmful to cells; therefore, excessive free cholesterol must be quickly esterified by acetyl-coenzyme A:cholesterol acetyltransferase (ACAT) and exported by scavenger receptor class B member I (SR-BI) or ATP-binding cassette protein A1 (ABCA1) from specific cells such as macrophage foam cells, which contain cholesteryl ester-derived vacuoles. Many vacuoles are present in the cytoplasm of Burkitt's lymphoma cells. In this study, we observed that these "vacuoles" are often seen in high-grade lymphomas. Cell culture study using lymphoma cell lines found that esterified cholesterol is the main component of these "vacuoles." and the expression of cholesterol metabolism-related molecules was significantly upregulated in lymphoma cell lines, with SR-BI and ACAT inhibitors (BLT-1 and CI-976, respectively) impeding lymphoma cell proliferation. Cytoplasmic free cholesterol was increased by ACAT and SR-BI inhibitors, and the accumulation of free cholesterol induced lymphoma cell apoptosis via inducing endoplasmic reticulum stress. Furthermore, synergistic effects of SR-BI and ACAT inhibitors were observed in a preclinical study. SR-BI inhibitor administration suppressed lymphoma progression in a tumor-bearing mouse model, whereas ACAT inhibitor did not. Therefore, SR-BI inhibitors are potential new antilymphoma therapeutics that target cholesterol metabolism.

Hybrid deep-learning-based denoising method for compressed sensing in pituitary MRI: comparison with the conventional wavelet-based denoising method

OBJECTIVES

This study aimed to evaluate the efficacy of a combined wavelet and deep-learning reconstruction (DLR) method for under-sampled pituitary MRI.

METHODS

This retrospective study included 28 consecutive patients who underwent under-sampled pituitary T2-weighted images (T2WI). Images were reconstructed using either the conventional wavelet denoising method (wavelet method) or the wavelet and DLR methods combined (hybrid DLR method) at five denoising levels. The signal-to-noise ratio (SNR) of the CSF, hypothalamic, and pituitary images and the contrast between structures were compared between the two image types. Noise quality, contrast, sharpness, artifacts, and overall image quality were evaluated by two board-certified radiologists. The quantitative and the qualitative analyses were performed with robust two-way repeated analyses of variance.

RESULTS

Using the hybrid DLR method, the SNR of the CSF progressively increased as denoising levels increased. By contrast, with the wavelet method, the SNR of the CSF, hypothalamus, and pituitary did not increase at higher denoising levels. There was a significant main effect of denoising methods (p < 0.001) and denoising levels (p < 0.001), and an interaction between denoising methods and denoising levels (p < 0.001). For all five qualitative scores, there was a significant main effect of denoising methods (p < 0.001) and an interaction between denoising methods and denoising levels (p < 0.001).

CONCLUSIONS

The hybrid DLR method can provide higher image quality for T2WI of the pituitary with compressed sensing (CS) than the wavelet method alone, especially at higher denoising levels.

KEY POINTS

• The signal-to-noise ratios of cerebrospinal fluid progressively increased with the hybrid DLR method, with an increase in the denoising level for cerebrospinal fluid in pituitary T2WI with CS. • The signal-to-noise ratios of cerebrospinal fluid using the conventional wavelet method did not increase at higher denoising levels. • All qualitative scores of hybrid deep-learning reconstructions at all denoising levels were higher than those for the wavelet denoising method.

Transcriptome and methylome analysis of CNS germ cell tumor finds its cell-of-origin in embryogenesis and reveals shared similarities with testicular counterparts

BACKGROUND

CNS germ cell tumors (GCTs) predominantly develop in pediatric and young adult patients with variable responses to surgery, radiation, and chemotherapy. This study aimed to examine the complex and largely unknown pathogenesis of CNS GCTs.

METHODS

We used a combined transcriptomic and methylomic approach in 84 cases and conducted an integrative analysis of the normal cells undergoing embryogenesis and testicular GCTs.

RESULTS

Genome-wide transcriptome analysis in CNS GCTs indicated that germinoma had a transcriptomic profile representative of primitive cells during early embryogenesis with high meiosis/mitosis potentials, while nongerminomatous GCTs (NGGCTs) had differentiated phenotypes oriented toward tissue formation and organogenesis. Co-analysis with the transcriptome of human embryonic cells revealed that germinomas had expression profiles similar to those of primordial germ cells, while the expression profiles of NGGCTs were similar to those of embryonic stem cells. Some germinoma cases were characterized by extensive immune-cell infiltration and high expression of cancer-testis antigens. NGGCTs had significantly higher immune-cell infiltration, characterized by immune-suppression phenotype. CNS and testicular GCTs (TGCTs) had similar mutational profiles; TGCTs showed enhanced copy number alterations. Methylation analysis clustered germinoma/seminoma and nongerminoma/nonseminoma separately. Germinoma and seminoma were co-categorized based on the degree of the tumor microenvironment balance.

CONCLUSIONS

These results suggested that the pathophysiology of GCTs was less dependent on their site of origin and more dependent on the state of differentiation as well as on the tumor microenvironment balance. This study revealed distinct biological properties of GCTs, which will hopefully lead to future treatment development.

[Precision Medicine for IDH-mutant Diffuse Glioma(Lower-grade Glioma)]

Several important revisions were made regarding the classification of brain tumors in the newest version(5th edition)of the WHO classification of tumours of the central nervous system published in 2021. Now, most so-called "lower-grade glioma(s)" fall into the category of IDH-mutant diffuse glioma, represented by astrocytoma and oligodendroglioma. For the diagnosis of these IDH-mutant gliomas, the determination of genetic alterations in IDH1/2, TP53, chromosome 1p/19q, ATRX, TERT promoter, and CDNK2A/B is important. Generally, in addition to the IDH mutation, astrocytomas have TP53 mutation and ATRX mutation, whereas oligodendrogliomas have 1p/19q codeletion and TERT promoter mutation. For tumor grading in the new WHO classification, astrocytomas harboring CDNK2A/B homozygous deletion can be categorized as WHO grade 4 astrocytomas, even though they do not have microvascular proliferation or necrosis. For these IDH-mutant tumors, molecular targeted therapy for IDH mutation has been under development. Several enzymatic inhibitors of IDH1/2 have been tested in clinical trials and were suggested to have some clinical effectiveness. Currently, large-scale trials are ongoing. Besides these inhibitors, other strategies for targeting IDH mutations, such as immunotherapy and therapy targeting aberrant metabolic pathways resulting from IDH mutation are also examined. These novel therapies will be beneficial to patients.