Comparison of transposition and interposition methods in microvascular decompression for hemifacial spasm: an analysis of 109 cases performed by a single surgeon in a single-center retrospective study.

BACKGROUND: Microvascular decompression (MVD), the standard surgical approach for hemifacial spasm (HFS), can be divided into the interposition and transposition methods. Although the risk of HFS recurrence following interposition has been reported, there is limited data comparing long-term outcomes between both methods performed by a single surgeon. This study aimed to investigate the efficacy of MVD techniques on HFS by comparing surgical outcomes performed by a single surgeon in a single-center setting. METHODS: A total of 109 patients who underwent MVD were analyzed and divided into the transposition (86 patients) and interposition (23 patients) groups. Postoperative outcomes at 1 month and 1 year were assessed and compared, including rates of spasm relief, complications, and recurrence. RESULTS: Outcome assessment revealed higher rates of early spasm relief in the interposition group (66.3% vs. 100%, transposition vs. interposition, respectively, p = 0.0004), although spasm relief at 1-year postoperatively was comparable between the two groups (84.9% vs. 95.7%, transposition vs. interposition, respectively, p = 0.2929). No significant differences were observed in complication and recurrence rates. Kaplan-Meier analysis demonstrated no significant differences in the duration of spasm resolution by MVD method (p = 0.4347, log-rank test). CONCLUSION: This study shows that both the transposition (Surgicel® and fibrin glue) and interposition (sponge) methods were excellent surgical techniques. The interposition method may achieve earlier spasm resolution compared to the transposition method.

Canagliflozin Inhibits Glioblastoma Growth and Proliferation by Activating AMPK.

Sodium-glucose transporter 2 (SGLT2) inhibitors are antidiabetic drugs affecting SGLT2. Recent studies have shown various cancers expressing SGLT2, and SGLT2 inhibitors attenuating tumor proliferation. We evaluated the antitumor activities of canagliflozin, a SGLT2 inhibitor, on glioblastoma (GBM). Three GBM cell lines, U251MG (human), U87MG (human), and GL261 (murine), were used. We assessed the expression of SGLT2 of GBM through immunoblotting, specimen-use, cell viability assays, and glucose uptake assay with canagliflozin. Then, we assessed phosphorylation of AMP-activated protein kinase (AMPK), p70 S6 kinase, and S6 ribosomal protein by immunoblotting. Concentrations of 5, 10, 20, and 40 µM canagliflozin were used in these tests. We also evaluated cell viability and immunoblotting using U251MG with siRNA knockdown of SGLT2. Furthermore, we divided the mice into vehicle group and canagliflozin group. The canagliflozin group was administrated with 100 mg/kg of canagliflozin orally for 10 days starting from the third days post-GBM transplant. The brains were removed and the tumor volume was evaluated using sections. SGLT2 was expressed in GBM cell and GBM allograft mouse. Canagliflozin administration at 40 µM significantly inhibited cell proliferation and glucose uptake into the cell. Additionally, canagliflozin at 40 µM significantly increased the phosphorylation of AMPK and suppressed that of p70 S6 kinase and S6 ribosomal protein. Similar results of cell viability assays and immunoblotting were obtained using siRNA SGLT2. Furthermore, although less effective than in vitro, the canagliflozin group significantly suppressed tumor growth in GBM-transplanted mice. This suggests that canagliflozin can be used as a potential treatment for GBM.

NMDA receptor signaling induces the chemoresistance of temozolomide via upregulation of MGMT expression in glioblastoma cells.

PURPOSE: The alkylating agent temozolomide (TMZ) has a significant impact on the prognosis of glioblastoma (GBM) patients. Therefore, maximizing TMZ efficacy is important for GBM treatment. Many reports have shown that glutamate signaling promotes GBM progression via glutamate receptors, including N-methyl-D-aspartate receptors (NMDARs). Although NMDARs promote cell migration and invasion of GBM cells, their role in TMZ resistance remains unclear. Therefore, we focused on NMDAR signaling and investigated its effects on TMZ resistance. METHODS: We investigated the effect of NMDAR signaling on O6-methylguanine DNA methyltransferase (MGMT), a DNA repair enzyme that induces chemoresistance to TMZ, using quantitative real-time polymerase chain reaction and western blotting in human GBM T98G cells. In addition, we used memantine (MEM), an NMDAR antagonist, to investigate the cytotoxic effect of TMZ/MEM combination and its detailed mechanism. RESULTS: Activation of NMDAR by N-methyl-D-aspartate (NMDA) elevated MGMT expression and suppressed the effect of TMZ in T98G cells. In contrast, knockdown of NMDAR by NMDAR1 shRNA decreased MGMT expression and enhanced the effect of TMZ in T98G cells. The cytotoxic effect of TMZ was enhanced by MEM in T98G cells. Inhibition of NMDAR by MEM decreased MGMT expression and increased DNA alkylation by TMZ. CONCLUSION: NMDAR signaling induced chemoresistance of TMZ via the upregulation of MGMT expression in GBM cells. Furthermore, MEM inhibited TMZ-induced MGMT upregulation and increased the cytotoxic effect of TMZ on MGMT-positive cells. This study demonstrates that the combination of TMZ and MEM could be a new therapeutic strategy for MGMT-positive GBM. Overview of this study. NMDAR signaling controls the expression of MGMT and the cytotoxic effect of TMZ.

Nafamostat protects against early brain injury after subarachnoid hemorrhage in mice.

This study aimed to evaluate the effects of nafamostat, a serin protease inhibitor, in the management of subarachnoid hemorrhage (SAH). SAH was induced by endovascular perforation in male mice. Nafamostat was administered intraperitoneally four times immediately after SAH induction. Cerebral blood flow, neurological behavior tests, SAH grade and protein expression were evaluated at 24 h after SAH induction. In the in vitro model, human brain microvascular endothelial cells (HBMVECs), HBVECs were exposed to thrombin and hypoxia for 24 h; nafamostat was administered and the protein expression was evaluated. Eighty-eight mice were included in the in vivo study. Fifteen mice (17%) were excluded because of death or procedure failure. Nafamostat exerted no significant effect on the SAH grade or cerebral blood flow; however, it improved the neurological behavior and suppressed the thrombin and MMP-9 expression. In addition, nafamostat suppressed the ICAM-1 expression and p38 phosphorylation in the in vitro study. Nafamostat has a protective effect against HBMVEC after exposure to thrombin and hypoxia, suggesting its role in improving the neurological outcomes after SAH. These findings indicate that nafamostat has the potential to be a novel therapeutic drug in the management of SAH.

Real-world treatment results for ruptured blood-blister aneurysm of the internal carotid artery: analysis of a Japanese nationwide multicenter study.

Ruptured blood-blister aneurysm (BBA) of the internal carotid artery (ICA) remains a challenging lesion, even in the age of modern neurosurgery and endovascular treatment. This retrospective multicenter study aimed to investigate the real-world treatment choice and treatment results. We included 182 ruptured BBAs of the ICA treated at 51 neurosurgical centers in Japan between 2013 and 2017. The baseline patient characteristics, radiological features of the aneurysm, treatment modality, details of treatment, complications of treatment, and treatment results were retrospectively collected. The treatment strategy was divided into deconstructive and reconstructive procedures. Primary clinical outcomes were evaluated using the modified Rankin scale (mRS) at final follow-up. Direct surgery was performed in 144 (79%) cases, and the remaining 38 (21%) cases received endovascular treatment. The majority of treatment selections were deconstructive and reconstructive procedures in the direct surgery group and endovascular treatment group, respectively. Overall, favorable clinical outcomes (mRS 0 to 2) were achieved in 66% of cases, and the mortality rate was 15% at the final follow-up (mean 23 months). There was no significant difference in clinical outcome between direct and endovascular treatment groups. Our large nationwide study compared the real-world treatment options for ruptured BBAs and their results. Our findings may offer beneficial information for treatment decision and for future studies investigating ruptured BBAs.

Tissue Protrusion With Attenuation Is Associated With Ischemic Brain Lesions After Carotid Artery Stenting.

Background and Purpose- Tissue protrusion between stent struts is frequently observed on optical frequency domain imaging evaluation after carotid artery stenting, but its clinical relevance is unclear. We aimed to investigate the association between the characteristics of tissue protrusion assessed by optical frequency domain imaging and brain lesions identified by diffusion-weighted imaging after carotid artery stenting. Methods- Sixty-five consecutive patients who underwent optical frequency domain imaging after protected carotid artery stenting were enrolled in the study. Cross-sectional optical frequency domain images within the stented segments were evaluated at 0.125-mm intervals. Magnetic resonance imaging was performed 1 to 10 days after treatment. The characteristics of tissue protrusion were compared between patients with and without new ipsilateral brain lesions on posttreatment magnetic resonance imaging. Results- Tissue protrusion was observed in 62 patients (95%). New brain lesions were observed in 24 patients (37%). In the multivariate analysis, the presence of protrusion with attenuation (odds ratio, 2.94 [95% CI, 1.05-8.68] P=0.04) was associated with new brain lesions after carotid artery stenting. Conclusions- The presence of protrusion with attenuation assessed by optical frequency domain imaging was associated with ipsilateral brain lesions after carotid artery stenting. Prevention or treatment of protrusions with attenuation may reduce ischemic brain lesions after carotid artery stenting.

A Rare Case of Symptomatic Carotid Stenosis Caused by Mechanical Stimulation by Thyroid Cartilage and Frequent Swimming.

BACKGROUND: Bony structures around the carotid artery such as the styloid process and hyoid bone can cause dissection, compression, plaque formation, and plaque rupture of the carotid artery. To the best of our knowledge, this case is the first finding of thyroid cartilage being the cause of a lesion corresponding to adjacent common carotid artery (CCA) atherosclerosis. CASE DESCRIPTION: A 51-year-old man with a history of hypertension and dyslipidemia suddenly experienced right facial numbness and dysphasia while front crawl swimming, which he usually did 3 times weekly. Diffusion-weighted magnetic resonance imaging showed high intensity areas in the left frontal and parietal lobes. He was diagnosed with acute cerebral infarction and was administered with tissue plasminogen activator. Angiography of the left CCA revealed mild stenosis with an intravascular filling defect, and carotid duplex ultrasonography of the CCA on the second day after symptom onset showed plaque and intraluminal thrombus at the stenotic site. Plain and contrast-enhanced computed tomography showed that thyroid cartilage contacted the left CCA at the stenotic site, and the left CCA moved backward and forward with the thyroid cartilage during neck rotation. We determined that mechanical stimulation by the thyroid cartilage had induced the plaque during the frequent neck rotation that is a feature of front crawl swimming. CONCLUSIONS: Evaluation of anatomical interactions between the carotid artery and bony structures including the thyroid cartilage is important to ensure that appropriate treatment is selected to prevent further ischemia.

Characteristics of time-activity curves obtained from dynamic 11C-methionine PET in common primary brain tumors.

PURPOSE: The aim of this study was to assess whether dynamic PET with 11C-methionine (MET) (MET-PET) is useful in the diagnosis of brain tumors. METHODS: One hundred sixty patients with brain tumors (139 gliomas, 9 meningiomas, 4 hemangioblastomas and 8 primary central nervous system lymphomas [PCNSL]) underwent dynamic MET-PET with a 3-dimensional acquisition mode, and the maximum tumor MET-standardized uptake value (MET-SUV) was measured consecutively to construct a time-activity curve (TAC). Furthermore, receiver operating characteristic (ROC) curves were generated from the time-to-peak (TTP) and the slope of the curve in the late phase (SLOPE). RESULTS: The TAC patterns of MET-SUVs (MET-TACs) could be divided into four characteristic types when MET dynamics were analyzed by dividing the MET-TAC into three phases. MET-SUVs were significantly higher in early and late phases in glioblastoma compared to anaplastic astrocytoma, diffuse astrocytoma and the normal frontal cortex (P < 0.05). The SLOPE in the late phase was significantly lower in tumors that included an oligodendroglial component compared to astrocytic tumors (P < 0.001). When we set the cutoff of the SLOPE in the late phase to - 0.04 h-1 for the differentiation of tumors that included an oligodendroglial component from astrocytic tumors, the diagnostic accuracy was 74.2% sensitivity and 64.9% specificity. The area under the ROC curve was 0.731. CONCLUSIONS: The results of this study show that quantification of the MET-TAC for each brain tumor identified by a dynamic MET-PET study could be helpful in the non-invasive discrimination of brain tumor subtypes, in particular gliomas.

Pathological analysis of the surgical margins of resected glioblastomas excised using photodynamic visualization with both 5-aminolevulinic acid and fluorescein sodium.

During glioma resection, 5-aminolevulinic acid (5-ALA) and fluorescein sodium (Fl-Na) are used for photodynamic tumor visualization. The objective of this study was to evaluate the pathological findings of the boundary zone between the tumor and adjacent normal brain in glioblastoma patients undergoing simultaneous double staining with 5-ALA and Fl-Na during surgery. Eight patients received 5-ALA (20 mg/kg orally) before the induction of general anesthesia, and Fl-Na (20 mg/kg) was administered intravenously before the dural incision was performed. The tumor bulk was removed under the guidance of Fl-Na staining alone using conventional white light. Subsequently, residual tumor was removed under the guidance of both fluorescent agents within functionally safe limits until both were visibly undetectable. Twenty specimens exhibiting different staining intensities of both agents were obtained. The vessel index (VI) was calculated from CD31 immunohistochemistry (IHC) samples. Boundary zone tumor cells were detected by IHC for olig2, and were expressed as the olig2 index (OLI). The VI was significantly higher in Fl-Na-positive areas than in Fl-Na-negative areas (p = 0.0005). In contrast, the OLI was significantly higher in 5-ALA-positive areas than in 5-ALA-negative areas (p = 0.0149). 5-ALA-positive/Fl-Na negative areas were observed in 7 patients. These findings indicate that Fl-Na accumulates in areas with a disrupted blood-brain barrier, and that 5-ALA fluorescence is dependent on tumor cell protoporphyrin IX metabolism. In conclusion, 5-ALA was better for detecting tumor cells in the boundary zone than was Fl-Na. Of note, tumor cells existed outside the fluorescence-stained boundaries of both agents.

Glycoprotein nonmetastatic melanoma protein B (GPNMB) promotes the progression of brain glioblastoma via Na+/K+-ATPase.

Glycoprotein nonmetastatic melanoma protein B (GPNMB), which is involved in invasion and metastasis, was found to be overexpressed in various cancers. High levels of GPNMB and Na+/K+-ATPase α subunits are associated with a poor prognosis in glioblastoma patients. We showed that GPNMB interacts with Na+/K+-ATPase α subunits to activate PI3K/Akt and MEK/ERK pathways. However, it remains unclear whether the interaction of GPNMB and Na+/K+-ATPase α subunits is involves in progression of glioma. The tumor size induced by the injection of glioma GL261 cells was larger in transgenic mice overexpressing GPNMB when compared with wild-type mice. Additionally, the interaction of GPNMB and Na+/K+-ATPase α subunits was identified in the murine glioma model and in the tumors of glioblastoma patients. Ouabain, a Na+/K+-ATPase inhibitor, suppressed the glioma growth induced by the injection of glioma cells in the transgenic mice overexpressing GPNMB and blocked the GPNMB-induced migration of glioma cells. These findings indicate that GPNMB promotes glioma growth via Na+/K+-ATPase α subunits. Thus, the interaction between GPNMB and Na+, K+-ATPase α subunits represents a novel therapeutic target for the treatment of brain glioblastomas.

Bevacizumab treatment leads to observable morphological and metabolic changes in brain radiation necrosis.

We investigated morphological and metabolic changes of radiation necrosis (RN) of the brain following bevacizumab (BEV) treatment by using neuroimaging. Nine patients with symptomatic RN, who had already been treated with radiation therapy for malignant brain tumors (6 glioblastomas, 1 anaplastic oligodendroglioma, and 2 metastatic brain tumors), were enrolled in this prospective clinical study. RN diagnosis was neuroradiologically determined with Gd-enhanced MRI and 11C-methionine positron emission tomography (MET-PET). RN clinical and radiological changes in MRI, magnetic resonance spectroscopy (MRS) and PET were assessed following BEV therapy. Karnofsky performance status scores improved in seven patients (77.8 %). Both volumes of the Gd-enhanced area and FLAIR-high area from MRI decreased in all patients after BEV therapy and the mean size reduction rates of the lesions were 80.0 and 65.0 %, respectively. MRS, which was performed in three patients, showed a significant reduction in Cho/Cr ratio after BEV therapy. Lesion/normal tissue (L/N) ratios in MET- and 11C-choline positron emission tomography (CHO-PET) decreased in 8 (89 %) and 9 patients (100 %), respectively, and the mean L/N ratio reduction rates were 24.4 and 60.7 %, respectively. BEV-related adverse effects of grade 1 or 2 (anemia, neutropenia and lymphocytopenia) occurred in three patients. These results demonstrated that BEV therapy improved RN both clinically and radiologically. BEV therapeutic mechanisms on RN have been suggested to be related not only to the effect on vascular permeability reduction by repairing the blood-brain barrier, but also to the effect on suppression of tissue biological activity, such as immunoreactions and inflammation.

Endoscope-assisted treatment for delayed cystic radiation necrosis after stereotactic radiosurgery for metastatic brain tumors: illustrative cases.

BACKGROUND: Cystic formation due to radiation necrosis in metastatic brain tumors is a rare condition. Surgical intervention is necessary if symptoms develop. Additionally, excising radiation necrosis lesions within the cyst is essential to prevent recurrence. Neuroendoscopic surgery is a minimally invasive method suitable for treating cystic diseases and accessing deep lesions in the brain. The authors herein present a method for removing radiation necrotic tissue from deep lesions of cystic radiation necrosis using neuroendoscopy. OBSERVATIONS: Endoscopic surgery was performed in two patients with symptomatic cystic radiation necrosis. Both cases involved multilocular cysts, with radiation necrosis located deep within the cyst. The authors performed a small craniotomy of approximately 3 cm and opened the cyst. After removing its contents, an endoscope was used to closely observe the interior of the cyst. Removal of the septum within the cyst allowed the endoscope to be inserted deeply. The authors identified and excised the nodular lesion diagnosed as radiation necrosis in the deep tissue. Following the surgery, the cyst shrank rapidly, and symptoms disappeared. Both patients showed no recurrence of the lesions. LESSONS: The authors performed minimally invasive surgery and achieved good outcomes. Endoscopic surgery was considered beneficial for treating cystic radiation necrosis. https://thejns.org/doi/10.3171/CASE24250.

Timeliness and accuracy of the 7-Item Japan Urgent Stroke Triage (JUST-7) score, a prehospital stroke triage tool, assessed by emergency medical services.

The prompt initiation of stroke treatment significantly influences patient outcomes, highlighting the crucial role of prehospital triage. This study aimed to assess the implementation of the 7-Item Japan Urgent Stroke Triage (JUST-7) score by emergency medical services (EMS) in our region and its effect on emergency transportation for suspected stroke patients. Data were collected from patients suspected of having an acute stroke with a Cincinnati Prehospital Stroke Scale (CPSS) score of 1 or more who were transferred by ambulance within 24 h of symptom onset. Two prehospital stroke scales were employed during different periods: period 1 with CPSS alone (January to December 2020) and period 2 with both CPSS and JUST-7 (January 2021 to March 2023). On-scene time data were obtained from the EMS crews, and data regarding the final diagnosis of patients and their outcomes were obtained from the respective hospitals to which the patients were transferred. These data were compared between periods 1 and 2 and between the CPSS and JUST-7. The results revealed that additional evaluation with JUST-7 did not affect ambulance transport time. The CPSS+JUST-7 approach demonstrated higher specificity in identifying stroke and major artery occlusion than with the CPSS alone; however, an appropriate cut-off value needs to be considered. The JUST-7 achieved a diagnostic concordance rate of 35.9% for the most likely stroke type and 64.0% for the first two most likely types. This research emphasizes the potential of JUST-7 as a valuable addition to prehospital stroke diagnosis protocols. Its flexibility in adapting cut-off values based on regional factors and available medical resources optimizes its utility in diverse healthcare settings. The JUST-7 score is a promising tool for improving patient outcomes through prompt and accurate prehospital assessments.

Brainstem volume, diffusion, and metabolism are associated with chronic consciousness disorders after traumatic brain injury.

BACKGROUND AND PURPOSE: We aimed to identify reliable neuroradiological features of the brainstem reflecting the neurological symptoms of patients with chronic disorders of consciousness (DOCs) due to severe traumatic brain injury (TBI). METHODS: We retrospectively examined 86 patients with chronic DOCs due to severe TBI caused by automobile accidents. We studied the relationships among (1) neurological symptoms, including consciousness level, (2) integrated cognitive/physical condition, and (3) neuroradiological features of the brainstem (brainstem volume on MRI, fractional anisotropy [FA] value in the brainstem, and standardized uptake value [SUV] of 18F-fluorodeoxyglucose [FDG] on positron emission tomography in the brainstem). RESULTS: Brainstem volume was significantly larger and FA values were significantly higher in patients with a better level of consciousness. However, brainstem volumes were significantly decreased and the maximum SUV (SUVmax ) of FDG significantly increased at 2 years following admission regardless of the level of consciousness at admission. The brainstem volume was significantly larger and the FA value and SUVmax of FDG were significantly higher in patients with better National Agency for Automotive Safety and Victims' Aid (NASVA) scores at admission. The decrease in the brainstem volume was significantly minimized and the SUVmax of FDG significantly increased in patients with more improvement in the NASVA score 2 years after admission. CONCLUSIONS: The volume, FA value, and SUVmax of FDG of the brainstem are important neuroradiological features associated with the neurological conditions of patients with chronic DOCs due to severe TBI.

The Height and Mobility of Protruding Plaque After Carotid Artery Stenting Are Associated with Postoperative Ischemic Lesions.

BACKGROUND: Tissue protrusion (TP) is a possible cause of cerebral infarction after carotid artery stenting (CAS). Using optical frequency domain imaging (OFDI) and angioscopy, we investigated the relationship between the morphological features of TP and postoperative new ischemic lesions on magnetic resonance imaging (MRI)-diffusion weighted imaging (DWI) after CAS. METHODS: Fifty patients who underwent CAS and subsequent poststenting intravascular evaluation using both OFDI and angioscopy were included. CAS was performed for proximal protection via the femoral artery approach, and intravascular evaluation with OFDI and angioscopy were performed after stent placement. We compared the background and poststenting intravascular findings between patients with and without postoperative new ischemic lesions on MRI-DWI. RESULTS: TP was observed in 42 patients (84%), and postoperative new ischemic lesions on MRI-DWI were observed in 32 patients (64%). The frequency of TP did not differ between the 2 groups, but the height of TP was higher in the DWI-positive group (0.62 mm vs. 0.29 mm, P = 0.0028), and mobile TP was observed only in the DWI-positive group. The height of TP (P = 0.023) was an independent predictor of new periprocedural ischemic brain lesions after CAS, and its cut-off value for mobility was 0.55 mm on the receiver operating characteristic curve (area under the curve, 0.93). CONCLUSIONS: The height of TP on OFDI and mobile-TP on angioscopy after CAS were associated with postoperative new ischemic lesions on MRI-DWI. The intravascular evaluation using OFDI and angioscopy could be helpful for a detailed evaluation of TP.

Clinical Significance of Early Venous Filling Detected via Preoperative Angiography in Glioblastoma.

Preoperative angiography in glioblastoma (GBM) often shows arteriovenous shunts and early venous filling (EVF). Here, we investigated the clinical implications of EVF in GBM as a prognostic and vascular mimicry biomarker. In this retrospective multicenter study, we consecutively enrolled patients who underwent angiography with a GBM diagnosis between 1 April 2013 and 31 March 2021. The primary and secondary endpoints were the differences in overall survival (OS) and progression-free survival (PFS), respectively, between cases with and without EVF. Of the 133 initially enrolled patients, 91 newly diagnosed with GBM underwent preoperative angiography and became the study population. The 6-year OS and PFS were significantly worse in the EVF than in the non-EVF group. Moreover, 20 GBM cases (10 with EVF and 10 without EVF) were randomly selected and evaluated for histological vascular mimicry. Except for two cases that were difficult to evaluate, the EVF group had a significantly higher frequency of vascular mimicry than the non-EVF group (0/8 vs. 5/10, p = 0.04). EVF on preoperative angiography is a robust prognostic biomarker for GBM and may help detect cases with a high frequency of histological vascular mimicry.

Differentiation of astrocytoma between grades II and III using a combination of methionine positron emission tomography and magnetic resonance spectroscopy.

Objective: This study aimed to establish a method for differentiating between grades II and III astrocytomas using preoperative imaging. Methods: We retrospectively analyzed astrocytic tumors, including 18 grade II astrocytomas (isocitrate dehydrogenase (IDH)-mutant: IDH-wildtype = 8:10) and 56 grade III anaplastic astrocytomas (37:19). We recorded the maximum methionine (MET) uptake ratios (tumor-to-normal: T/N) on positron emission tomography (PET) and three MRS peak ratios: choline (Cho)/creatine (Cr), N-acetyl aspartate (NAA)/Cr, and Cho/NAA, between June 2015 and June 2020. We then evaluated the cut-off values to differentiate between grades II and III. We compared the grading results between contrast enhancement effects on MR and combinational diagnostic methods (CDM) on a scatter chart using the cutoff values of the T/N ratio and MRS parameters. Results: The IDH-mutant group showed significant differences in the Cho/NAA ratio between grades II and III using univariate analysis; however, multiple regression analysis results negated this. The IDH-wildtype group showed no significant differences between the groups. Contrast enhancement effects also showed no significant differences in IDH status. Accordingly, regardless of the IDH status, no statistically independent factors differentiated between grades II and III. However, CDMs showed higher sensitivity and negative predictive value in distinguishing them than MRI contrast examinations for both IDH statuses. We demonstrated a significantly higher diagnostic rate of grade III than of grade II with CDM, which was more striking in the IDH-mutant group than in the wild-type group. Conclusions: CDM could be valuable in differentiating between grade II and III astrocytic tumors.

Multidrug chemotherapy, whole-brain radiation and cytarabine therapy for primary central nervous system lymphoma in elderly patients with dose modification based on geriatric assessment: study protocol for a phase II, multicentre, non-randomised study.

INTRODUCTION: Multidrug chemoimmunotherapy with rituximab, high-dose methotrexate, procarbazine and vincristine (R-MPV) is a standard therapy for younger patients with primary central nervous system lymphoma (PCNSL); however, prospective data regarding its use in elderly patients are lacking. This multi-institutional, non-randomised, phase II trial will assess the efficacy and safety of R-MPV and high-dose cytarabine (HD-AraC) for geriatric patients with newly diagnosed PCNSL. METHODS AND ANALYSIS: Forty-five elderly patients will be included. If R-MPV does not achieve complete response, the patients will undergo reduced-dose, whole-brain radiotherapy comprising 23.4 Gy/13 fractions, followed by local boost radiotherapy comprising 21.6 Gy/12 fractions. After achieving complete response using R-MPV with or without radiotherapy, the patients will undergo two courses of HD-AraC. All patients will undergo baseline geriatric 8 (G8) assessment before HD-AraC and after three, five and seven R-MPV courses. Patients with screening scores of ≥14 points that decrease to <14 points during subsequent treatment, or those with screening scores <14 points that decrease from the baseline during subsequent treatment are considered unfit for R-MPV/HD-AraC. The primary endpoint is overall survival, and the secondary endpoints are progression-free survival, treatment failure-free survival and frequency of adverse events. The results will guide a later phase III trial and provide information about the utility of a geriatric assessment for defining chemotherapy ineligibility. ETHICS AND DISSEMINATION: This study complies with the latest Declaration of Helsinki. Written informed consent will be obtained. All participants can quit the study without penalty or impact on treatment. The protocol for the study, statistical analysis plan and informed consent form have been approved by the Certified Review Board at Hiroshima University (CRB6180006) (approval number: CRB2018-0011). The study is ongoing within nine tertiary and two secondary hospitals in Japan. The findings of this trial will be disseminated through national and international presentations and peer-reviewed publications. TRIAL REGISTRATION: jRCTs061180093.