Metabolic profiling of atypical meningioma and recurrent meningioma: a comparative analysis with proton magnetic resonance spectroscopy.

OBJECTIVE: Meningiomas are predominantly benign, but some cases exhibit recurrent growth after surgery and undergo malignant transformation to WHO grade 2 or grade 3. Despite progress in genetic analyses, advancements in metabolomic analysis remain less established. Herein, the authors investigated metabolic activity differences between WHO grade 1 meningiomas and WHO grade 2 or 3 meningiomas by noninvasively using proton magnetic resonance spectroscopy (1H-MRS), aiming to preoperatively estimate malignancy. They also reviewed the literature to elucidate this aspect of meningioma research. METHODS: At Ryukyu University Hospital, the authors focused on 93 patients diagnosed with meningioma between 2011 and 2021. The inclusion criteria encompassed prior surgery, pathological diagnoses of meningioma, and preoperative 1H-MRS. Group I included 71 patients with WHO grade 1 meningioma and group II included 22 patients, comprising 19 and 3 with WHO grade 2 and 3 meningioma, respectively. The authors retrospectively conducted a comparative analysis of patient backgrounds and tumor metabolites. RESULTS: Group I and II did not differ significantly in terms of patient demographic characteristics (age and sex). Group II demonstrated a significantly lower extent of tumor resection (p < 0.01), higher MIB-1 labeling index (LI) (p < 0.05), higher incidence of prior irradiation (p < 0.001), and increased rate of tumor recurrence (p = 0.005) compared to group I. According to 1H-MRS, all metabolites, except lactate, displayed significantly higher median creatine (Cr) ratios in group II than group I: glutamine/Cr was 8.46, glutamate/Cr was 9.49, lipid/Cr was 11.36, and choline/Cr was 2.77. According to the receiver operating characteristic (ROC) analysis, glutamine had the largest area under the curve of 0.765 among 10 metabolites, and the cutoff value for distinguishing between group I and II was 5.76. CONCLUSIONS: In cases pathologically graded as WHO grade 2 or 3 meningiomas, metabolic products such as glutamine, glutamate, lipids, and choline increased significantly. These changes were correlated with elevation of the MIB-1 LI. In group II, the mean MIB-1 LI was 8.58, significantly higher than in group I, suggesting a strong association with pathological malignancy. Therefore, 1H-MRS may help to noninvasively predict tumor metabolic activity and tumor recurrence. Furthermore, the authors concluded from the ROC analysis that glutamine may be a potential indicator of future growth of meningioma and benefits of early surgery.

Outcome of endoscopic transsphenoidal surgery for acromegaly: Comparison of using and not using the floor standing pneumatic powered endoscope-holder system.

Introduction: Endoscopic transsphenoidal surgery can be performed by two surgeons, including an endoscopist (PE/2S), and by a single surgeon with an endoscope-holder system (PE/1S + H). We analyzed the surgical outcome, and outcome predictors in acromegaly patients in endoscopic transsphenoidal surgery using floor standing pneumatic endoscope-holder system. Methods: Endoscopic transsphenoidal surgery was performed with PE/1S+H (n = 51) and PE/2S (n = 20). Postoperative remission was evaluated by the 2010 consensus criteria for acromegaly. We compared the surgical results of PE/2S style and PE/1S+H style, and investigated the factors associated with favorable surgical outcomes. Results: There was no difference in clinical background between the PE/2S and the PE/1S + H groups. The remission rates for PE/2S and PE/1S+H were 65.0% and 82.4%, respectively, with no significant difference (p = 0.128). In consecutive 71 cases, statistically useful predictors of remission were low preoperative growth hormone (GH) level (<12 ng/mL), low Knosp grade (0-2), and low revised Knosp grade (0-3A). In the conventional Knosp grade 0-2 and 3/4, the sensitivity was 0.76 and the specificity was 0.81. In the revised Knosp grade 0-3A and 3B/4, the sensitivity was 0.96 and the specificity was 0.44. Conclusion: The outcome of GH-producing pituitary neuroendocrine tumors surgically removed by PE/1S+H could be almost equivalent to that by PE/2S. Preoperative low GH level and Knosp grades, including revised Knosp grades, are useful preoperative predictors for surgical remission of acromegaly.

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.

Recovery from the damage of cranial radiation modulated by memantine, an NMDA receptor antagonist, combined with hyperbaric oxygen therapy.

BACKGROUND: Radiotherapy is an important treatment option for central nervous system malignancies. However, cranial radiation induces hippocampal dysfunction and white matter injury; this leads to cognitive dysfunction, and results in a reduced quality of life in patients. Excitatory glutamate signaling through N-methyl-d-aspartate receptors (NMDARs) plays a central role both in hippocampal neurogenesis and in the myelination of oligodendrocytes in the cerebrum. METHODS: We provide a method for quantifying neurogenesis in human subjects in live brain during cancer therapy. Neuroimaging using originally created behavioral tasks was employed to examine human hippocampal memory pathway in patients with brain disorders. RESULTS: Treatment with memantine, a non-competitive NMDAR antagonist, reversed impairment in hippocampal pattern separation networks as detected by functional magnetic resonance imaging. Hyperbaric preconditioning of the patients just before radiotherapy with memantine mostly reversed white matter injury as detected by whole brain analysis with Tract-Based Spatial Statics. Neuromodulation combined with the administration of hyperbaric oxygen therapy and memantine during radiotherapy facilitated the restoration of hippocampal function and white matter integrity, and improved higher cognitive function in patients receiving cranial radiation. CONCLUSIONS: The method described herein, for diagnosis of hippocampal dysfunction, and therapeutic intervention can be utilized to restore some of the cognitive decline experienced by patients who have received cranial radiation. The underlying mechanism of restoration is the production of new neurons, which enhances functionality in pattern separation networks in the hippocampi, resulting in an increase in cognitive score, and restoration of microstructural integrity of white matter tracts revealed by Tract-Based Spatial Statics Analysis.

Primary diffuse leptomeningeal atypical teratoid rhabdoid tumor (AT/RT) demonstrating atypical imaging findings in an adolescent patient.

Atypical teratoid rhabdoid tumor (AT/RT) is a highly malignant central nervous system embryonal tumor, which typically affects the posterior fossa of young children. Primary diffuse leptomeningeal AT/RT, affecting the leptomeninges without any intraparenchymal mass in the brain and spinal cord, is an extremely rare form of AT/RT. Only 5 such cases have been reported previously, none of which underwent Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography (FDG-PET). We herein report a case of primary leptomeningeal AT/RT in an adolescent patient who underwent computed tomography, magnetic resonance imaging and FDG-PET. The computed tomography and magnetic resonance imaging indicated diffusely thickened leptomeninges without any intraparenchymal masses in the head and spine. Furthermore, there were multiple nodules on the thickened leptomeninges. On FDG-PET, the thickened leptomeninges and nodules demonstrated a lower standardized uptake value than that of the normal cerebral cortex. Biopsy and histopathological studies confirmed the diagnosis of AT/RT. Despite its rare occurrence, it is important to recognize primary diffuse leptomeningeal AT/RT for correct diagnosis and management of patients.

Clinicopathological characteristics of circumscribed high-grade astrocytomas with an unusual combination of BRAF V600E, ATRX, and CDKN2A/B alternations.

We report four cases of high-grade astrocytoma with a BRAF V600E mutation, ATRX inactivation, and CDKN2A/B homozygous deletion. Children to young adults aged 3-46 presented with a well demarcated contrast-enhancing mass in the supratentorial area. Pathological examination revealed packed growth of short spindle to round polygonal cells including some pleomorphic cells. The tumors had less ability to infiltrate into the adjacent brain parenchyma and presented a circumscribed growth pattern. Mitosis was readily found, accompanied by focal necrosis and/or microvascular proliferation. Tumors were histologically similar in part to pleomorphic xanthoastrocytoma (PXA) or anaplastic PXA, but did not fit criteria for either neoplasm. A BRAF V600E mutation and homozygous deletion of CDKN2A/B were observed, which is similar to the genetic features of PXA or epithelioid glioblastoma, but the additional loss of ATRX nuclear immunoreactivity and absence of TERT promoter mutation were unusual findings, indicating a novel genetic profile. Despite their malignant histological features, all patients had a favorable clinical course and remained alive for 6 months to 28 years under standard medical treatment for malignant glioma. In summary, high grade astrocytomas with BRAF V600E, ATRX, and CDKN2A/B alternations had unique clinicopathological features and may be a novel subset of high grade glioma.

The usefulness of indocyanine green during surgery for hypervascular posterior fossa tumors.

BACKGROUND: Cerebral hemangioblastomas are benign tumors with abundant blood flow that occur mainly in the posterior fossa. Tumor removal en bloc is important in surgical treatment because of the risk of bleeding; however, it is actually rather difficult in practice. Therefore, we propose a surgical strategy for visualizing hypervascular tumors of the posterior fossa utilizing indocyanine green (ICG). CASE DESCRIPTION: Case 1 involved a 48-year-old male with a history of von Hippel-Lindau (VHL) disease. Magnetic resonance imaging (MRI) revealed a solid tumor measuring 3.0 cm in diameter in the right cerebellopontine angle. We performed surgery because the tumor was pressing against the brainstem. Surgery was performed via the posterior subtemporal transtentorial approach in order to visualize the feeding artery and draining vein intraoperatively. The vessels were confirmed by ICG and the tumor was removed en bloc. Case 2 involved a 30-year-old woman. Signs of increased intracranial pressure were noted, and an MRI revealed a solid tumor 3.5 cm in diameter in the left cerebellar hemisphere. Surgery was performed via the midline suboccipital approach. Similarly, we confirmed the vessels using ICG and the tumor was removed en bloc. CONCLUSIONS: For hypervascular tumors of the posterior fossa, preoperative image assessment is important. Furthermore, the use of ICG during surgery is advantageous for surgical strategies where the feeding arteries and draining veins exist superficially in the operative field and are therefore easier to remove en bloc.

A case of high-grade astrocytoma with BRAF and ATRX mutations following a long-standing course over two decades.

Pediatric high-grade gliomas are rare and occasionally hard to classify. These tumors often feature a well-demarcated histology and are expected to have a better outcome than ordinary diffuse high-grade gliomas in adults. We herein report a case of circumscribed high-grade glioma that showed a distinct molecular profile and followed an excellent course for 26 years. The patient, a 3-year-old boy at onset, presented with a contrast-enhancing mass in the right temporal lobe and underwent resection. Histologically, the tumor mainly consisted of compact bundles of GFAP-positive spindle cells. With its malignant features including brisk mitotic activity and pseudopallisading necrosis, a diagnosis of high-grade astrocytoma was made and adjuvant chemoradiotherapy was administered. After a disease-free period of two decades, the tumor recurred locally. The resected tumor was histologically identical to the primary tumor and additionally contained pleomorphic cells, but lacked eosinophilic granular bodies and reticulin networks. The primary and recurrent tumors both harbored the BRAF V600E mutation, and the recurrent tumor was immunonegative for ATRX. Combined BRAF and ATRX mutations are rare in gliomas, with only a pediatric case of glioblastoma being reported in the literature. However, our case cannot be regarded as glioblastoma because of its well-demarcated histology and excellent course. The distinction of either a diffuse or localized nature in gliomas is important, particularly in children, for predicting prognoses and selecting adjuvant therapies that consequently affect life-long health care. The present case provides novel insights into pediatric high-grade astrocytomas.

Cerebellar Contribution to Pattern Separation of Human Hippocampal Memory Circuits.

The cerebellum is a crucial structure for cognitive function as well as motor control. Benign brain tumors such as schwannomas, meningiomas, and epidermoids tend to occur in the cerebellopontine angle cisterns and may cause compression of the posterior lateral cerebellum near the superior posterior fissure, where the eloquent area for cognitive function was recently identified. The present study examined cognitive impairment in patients with benign cerebellar tumors before and after surgical intervention in order to clarify the functional implications of this region in humans. Patients with cerebellar tumors showed deficits in psychomotor speed and working memory compared with healthy controls. Moreover, these impairments were more pronounced in patients with right cerebellar tumors. Functional magnetic resonance imaging during performance of a lure task also demonstrated that cerebellar tumors affected pattern separation or the ability to distinguish similar experiences of episodic memory or events with discrete, non-overlapping representations, which is one of the important cognitive functions related to the hippocampus. The present findings indicate that compression of the human posterior lateral cerebellum affects hippocampal memory function.

SLC44A1-PRKCA fusion in papillary and rosette-forming glioneuronal tumors.

We investigated the fused protein of solute carrier family 44 choline transporter member 1 (SLC44A1) and protein kinase C alpha (PRKCA) in three patients with papillary glioneuronal tumors (PGNT). PGNT and rosette-forming glioneuronal tumors (RGNT) are recently identified, unusual glioneuronal tumor variants which were categorized as novel tumor entities in the 2007 World Health Organization classification system. The molecular background of these tumors remains poorly understood due to the paucity of studies. The SLC44A1-PRKCA fusion was recently detected in three cases of PGNT. We invesitgated for the SLC44A1-PRKCA fusion protein in the three PGNT patients and a further two with RGNT using fluorescence in situ hybridization. Two out of the three PGNT patients had a fused signal (paired red-green signal) representing a rearrangement on chromosomes 9 and 17. A normal signal pattern was observed in the third PGNT patient. Neither of the two RGNT patients demonstrated a fused signal. This suggests that the SLC44A1-PRKCA fusion is a characteristic alteration in PGNT but not RGNT. Therefore, it is a potential biomarker of PGNT. The paired red-green signal that was observed in the PGNT patients implies the presence of a different breakpoint than that previously reported in the 9q31 and 17q24 genes.

Identification of a novel cell-penetrating peptide targeting human glioblastoma cell lines as a cancer-homing transporter.

Cell-penetrating peptides (CPPs) as a novel biomedical delivery system have been highly anticipated, since they can translocate across biological membranes and are capable of transporting their cargo inside live cells with minimal invasiveness. However, non-selective internalization in various cell types remains a challenge in the clinical application of CPPs, especially in cancer treatment. In this study, we attempted to identify novel cancer-homing CPPs to target glioblastoma multiforme (GBM), which is often refractory and resistant to treatment. We screened for CPPs showing affinity for the human GBM cell line, U87MG, from an mRNA display random peptide library. One of the candidate peptides which amino-acid sequence was obtained from the screening showed selective cell-penetrating activity in U87MG cells. Conjugation of the p16(INK4a) functional peptide to the GBM-selective CPP induced cellular apoptosis and reduced phosphorylated retinoblastoma protein levels. This indicates that the CPP was capable of delivering a therapeutic molecule into U87MG cells inducing apoptosis. These results suggest that the novel CPP identified in this study permeates with high affinity into GBM cells, revealing it to be a promising imaging and therapeutic tool in the treatment of glioblastoma.

Development of an experimentally useful model of acute myocardial infarction: 2/3 nephrectomized triple nitric oxide synthases-deficient mouse.

We investigated the effect of subtotal nephrectomy on the incidence of acute myocardial infarction (AMI) in mice deficient in all three nitric oxide synthases (NOSs). Two-thirds nephrectomy (NX) was performed on male triple NOSs(-/-) mice. The 2/3NX caused sudden cardiac death due to AMI in the triple NOSs(-/-) mice as early as 4months after the surgery. The 2/3NX triple NOSs(-/-) mice exhibited electrocardiographic ST-segment elevation, reduced heart rate variability, echocardiographic regional wall motion abnormality, and accelerated coronary arteriosclerotic lesion formation. Cardiovascular risk factors (hypertension, hypercholesterolemia, and hyperglycemia), an increased number of circulating bone marrow-derived vascular smooth muscle cell (VSMC) progenitor cells (a pro-arteriosclerotic factor), and cardiac up-regulation of stromal cell-derived factor (SDF)-1α (a chemotactic factor of the progenitor cells) were noted in the 2/3NX triple NOSs(-/-) mice and were associated with significant increases in plasma angiotensin II levels (a marker of renin-angiotensin system activation) and urinary 8-isoprostane levels (a marker of oxidative stress). Importantly, combined treatment with a clinical dosage of an angiotensin II type 1 receptor blocker, irbesartan, and a calcium channel antagonist, amlodipine, markedly prevented coronary arteriosclerotic lesion formation and the incidence of AMI and improved the prognosis of those mice, along with ameliorating all those pro-arteriosclerotic parameters. The 2/3NX triple NOSs(-/-) mouse is a new experimentally useful model of AMI. Renin-angiotensin system activation, oxidative stress, cardiovascular risk factors, and SDF-1α-induced recruitment of bone marrow-derived VSMC progenitor cells appear to be involved in the pathogenesis of AMI in this model.

Usefulness of the apparent diffusion coefficient (ADC) for predicting the consistency of intracranial meningiomas.

Meningioma consistency is an important factor for surgical treatment. Tumor cellularity and fibrous tissue contribute to the consistency of tumors, and it is proposed that the minimum apparent diffusion coefficient (ADC) value is significantly correlated with meningioma consistency. Twenty-seven consecutive patients with 28 meningiomas were retrospectively enrolled. Minimum ADC values in meningiomas with a hard consistency were significantly lower than those with a soft consistency. The minimum ADC value might have clinical use as a predictor of meningioma consistency.

Enhanced expression of proapoptotic and autophagic proteins involved in the cell death of glioblastoma induced by synthetic glycans.

OBJECT: Glioblastoma is the most aggressive malignant brain tumor, and overall patient survival has not been prolonged even by conventional therapies. Previously, the authors found that chemically synthesized glycans could be anticancer agents against growth of a series of cancer cells. In this study, the authors examined the effects of glycans on the growth of glioblastoma cells both in vitro and in vivo. METHODS: The authors investigated not only the occurrence of changes in the cell signaling molecules and expression levels of various proteins related to cell death, but also a mouse model involving the injection of glioblastoma cells following the administration of synthetic glycans. RESULTS: Synthetic glycans inhibited the growth of glioblastoma cells, induced the apoptosis of the cells with cleaved poly (adenosine diphosphate-ribose) polymerase (PARP) expression and DNA fragmentation, and also caused autophagy, as shown by the detection of autophagosome proteins and monodansylcadaverine staining. Furthermore, tumor growth in the in vivo mouse model was significantly inhibited. A dramatic induction of programmed cell death was found in glioblastoma cells after treatment with synthetic glycans. CONCLUSIONS: These results suggest that synthetic glycans could be a promising novel anticancer agent for performing chemotherapy against glioblastoma.

Progression of cerebellar chronic encapsulated expanding hematoma during late pregnancy after gamma knife radiosurgery for arteriovenous malformation.

BACKGROUND: The etiology and appropriate management strategy of chronic encapsulated expanding hematoma during pregnancy after gamma knife radiosurgery for arteriovenous malformation (AVM) remain unclear. CASE DESCRIPTION: A 34-year-old female developed chronic encapsulated expanding hematoma during late pregnancy, after angiographic disappearance of cerebellar AVM following two courses of gamma knife radiosurgery. The present case implicates pregnancy as a potential promoter of growth and enlargement of chronic encapsulated expanding hematoma, which may become life-threatening and require surgical intervention. CONCLUSION: Immediate surgical management after delivery may be associated with a favorable outcome, so close follow-up management and patient education are very important in women planning pregnancy.

Long-term treatment with san'o-shashin-to, a kampo medicine, markedly ameliorates cardiac ischemia-reperfusion injury in ovariectomized rats via the redox-dependent mechanism.

BACKGROUND: Hormone replacement therapy has failed to reduce ischemic cardiovascular events in climacteric women. To explore alternative therapy, we examined whether san'o-shashin-to (TJ-113), a kampo medicine, ameliorates cardiac ischemia-reperfusion (IR) injury in a climacteric rat model. METHODS AND RESULTS: Cardiac function and infarct size after IR were significantly exacerbated in ovariectomized rats as compared with sham-operated rats, whereas long-term treatment with a clinical dosage of TJ-113 for 4 weeks markedly improved these functional and morphological changes. Myocardial inducible nitric oxide synthase (iNOS) expression and peroxynitrite levels were significantly higher in ovariectomized rats compared with sham-operated rats, and long-term TJ-113 treatment significantly reduced these oxidative changes. Furthermore, myocardial manganese superoxide dismutase (Mn-SOD) activity was significantly lower in ovariectomized than in sham-operated rats, and long-term TJ-113 treatment significantly restored antioxidant activity. Importantly, those beneficial actions of TJ-113 were significantly inhibited by the estrogen receptor antagonist, fulvestrant, and the phytoestrogen, emodin, a TJ-113 ingredient, mimicked the actions of TJ-113, suggesting involvement of emodin in the effects of TJ-113. CONCLUSIONS: These results provide the first evidence that long-term treatment with a clinical dosage of TJ-113 markedly ameliorates cardiac IR injury in ovariectomized rats via inhibition of iNOS expression, suppression of peroxynitrite formation, and restoration of Mn-SOD activity. TJ-113 may be a novel therapeutic option in the treatment of ischemic heart disease in climacteric women.

Enhanced antitumor effect of YM872 and AG1296 combination treatment on human glioblastoma xenograft models.

OBJECT: Blockade of Ca(++)-permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR) inhibits the proliferation of human glioblastoma by inhibiting Akt phosphorylation, which is independent of the phosphatidylinositol 3-kinase pathway. Inhibiting platelet-derived growth factor receptor (PDGFR)-mediated phosphorylation causes growth inhibition in glioblastoma cells. The authors of this study investigated the effects of YM872 and AG1296, singly and in combination and targeting different pathways upstream of Akt, on Akt-mediated tumor growth in glioblastoma cells in vivo and in vitro. METHODS: The expression of AMPAR, PDGFR, and c-kit in glioblastoma cells was analyzed via immunofluorescence. Glioblastoma cells, both in culture and in xenografts grown in mice, were treated with YM872 and AG1296, singly or in combination. Inhibition of tumor growth was observed after treatment in the xenograft model. Cell proliferation assays were performed using anti-Ki 67 antibody in vivo and in vitro. The CD34-positive tumor vessel counts within the vascular hot spots of tumor specimens were evaluated. Phosphorylation of Akt was studied using Western blot analysis. RESULTS: Combined administration of YM872 and AG1296 had a significant enhanced effect on the inhibition of cell proliferation and reduction of tumor vascularity in the xenograft model. These agents singly and in combination demonstrated a significant reduction of Akt phosphorylation at Ser473 and inhibition of tumor proliferation in vitro, although combined administration had no enhanced antitumor effects. CONCLUSIONS: The strongly enhanced antitumor effect of this combination therapy in vivo rather than in vitro may be attributable to disruption of the aberrant vascular niche. This combination therapy might provide substantial benefits to patients with glioblastoma.

Phase II trial of radiotherapy after hyperbaric oxygenation with multiagent chemotherapy (procarbazine, nimustine, and vincristine) for high-grade gliomas: long-term results.

PURPOSE: To analyze the long-term results of a Phase II trial of radiotherapy given immediately after hyperbaric oxygenation (HBO) with multiagent chemotherapy in adults with high-grade gliomas. METHODS AND MATERIALS: Patients with histologically confirmed high-grade gliomas were administered radiotherapy in daily 2 Gy fractions for 5 consecutive days per week up to a total dose of 60 Gy. Each fraction was administered immediately after HBO, with the time interval from completion of decompression to start of irradiation being less than 15 minutes. Chemotherapy consisting of procarbazine, nimustine, and vincristine and was administered during and after radiotherapy. RESULTS: A total of 57 patients (39 patients with glioblastoma and 18 patients with Grade 3 gliomas) were enrolled from 2000 to 2006, and the median follow-up of 12 surviving patients was 62.0 months (range, 43.2-119.1 months). All 57 patients were able to complete a total radiotherapy dose of 60 Gy immediately after HBO with one course of concurrent chemotherapy. The median overall survival times in all 57 patients, 39 patients with glioblastoma and 18 patients with Grade 3 gliomas, were 20.2 months, 17.2 months, and 113.4 months, respectively. On multivariate analysis, histologic grade alone was a significant prognostic factor for overall survival (p < 0.001). During treatments, no patients had neutropenic fever or intracranial hemorrhage, and no serious nonhematologic or late toxicities were seen in any of the 57 patients. CONCLUSIONS: Radiotherapy delivered immediately after HBO with multiagent chemotherapy was safe, with virtually no late toxicities, and seemed to be effective in patients with high-grade gliomas.