Shunichiro Miki

Carotid artery stenting without post-stenting balloon dilatation

Purpose To evaluate the clinical outcome and MRI findings after carotid artery stenting (CAS) without post-dilatation. Methods Between May 2005 and April 2012, a total of 169 consecutive patients (61.4% symptomatic) underwent 176 CAS procedures performed with an embolic protection device (GuardWire, n=116; FilterWire EZ, n=60). All stents were deployed without post-dilatation. Periprocedural complications and mid-term outcomes were analyzed. Results The stroke rate was 2.3% within 30u2005days post-CAS (asymptomatic patients 1.5%; symptomatic patients 2.8%). Cerebral infarction occurred in one asymptomatic patient (1.5%) and one symptomatic patient (0.9%). Intracranial hemorrhage occurred in two symptomatic patients (1.9%). Post-CAS diffusion-weighted imaging (DWI) revealed a high-intensity area in 26 of 176 procedures (14.8%). Ipsilateral stroke after 31u2005days occurred in two patients (1.1%) and restenosis occurred in six (3.4%). A post-CAS comparison of the embolic protection devices revealed no difference in stroke incidence within 30u2005days and in DWI high-intensity area. Conclusions Our CAS procedure without post-dilatation is feasible, safe and associated with a low incidence of stroke and restenosis.

Photodynamic Diagnosis Using 5-Aminolevulinic Acid in 41 Biopsies for Primary Central Nervous System Lymphoma

We evaluated the feasibility of 5‐aminolevulinic acid (5‐ALA)‐mediated photodynamic diagnosis (PDD) in the biopsy for primary central nervous system lymphoma (PCNSL). 5‐ALA (20 mg kg−1) was administered orally 4 hours preoperatively. Forty‐one biopsies obtained under PDD in 47 consecutive biopsies (46 patients) that were finally pathologically diagnosed as PCNSL were evaluated. Positive fluorescence was observed in 34 of those 41 biopsies (82.9%). An intraoperative pathological diagnosis (IOD) of suspected PCNSL was made in 21 of the biopsies with positive fluorescence (61.8%). However, the eight IODs in the remaining 13 biopsies (23.5%) were not correct (atypical cell, 4; high‐grade glioma, 1; gliosis, 1; unremarkable, 2). In those 8 biopsies, PCNSL was confirmed by the final pathological diagnosis. There was no difference in the mean Mib‐1 labeling index between the biopsies with positive fluorescence (86.5%) and those without positive fluorescence (90.0%). IOD was not performed in 6 biopsies; however, 5 of those biopsies (83.3%) showed positive fluorescence and were finally pathologically diagnosed as PCNSL. Use of PDD in biopsies for patients with suspected PCNSL is a reliable way of obtaining specimens of adequate quality for the final pathological diagnosis and may lead to improved diagnostic yield in the biopsy of PCNSL.

Diffusely Infiltrating Cerebellar Anaplastic Astrocytoma Effectively Controlled with Bevacizumab: Case Report and Literature Review

BACKGROUNDnGliomas that show extensive diffuse infiltration from the cerebellum to the brainstem without masslike expansion are extremely rare. The efficacy of bevacizumab treatment for diffusely infiltrating gliomas remains uncertain.nnnCASE DESCRIPTIONnA 75-year-old man presented with a cerebellar anaplastic astrocytoma showing diffuse infiltration to the brainstem without a definite mass. He had experienced rapidly progressive nausea and dysarthria, as well as vertigo and headache for 2 months. Magnetic resonance imaging (MRI) revealed a poorly demarcated T2 high-intensity area in the right cerebellum and brainstem. The tumor in the right cerebellum showed sparse enhancement with gadolinium (Gd). Suboccipital decompressive craniotomy and partial removal of the tumor was emergently performed because of the rapid progression of symptoms and severe tonsillar herniation demonstrated on MRI. The pathologic diagnosis was anaplastic astrocytoma, and genomic analyses revealed no mutation in IDH1, H3F3A, or BRAF. During concomitant chemoradiotherapy with temozolomide, rapid worsening of the neurologic symptoms developed and significant enlargement of the T2 high-intensity area extending to the cerebral peduncle was seen, as well as a new Gd-enhancing lesion in the midbrain. After administration of bevacizumab, the neurologic symptoms gradually improved, the T2 high-intensity area decreased, and the Gd-enhancing lesion disappeared. At follow-up 2 years after the operation, no worsening of neurologic symptoms was seen and the residual T2 high-intensity area remained unchanged on MRI.nnnCONCLUSIONSnBevacizumab treatment may be a salvage treatment option for patients with diffusely infiltrating cerebellar gliomas that exhibits rapid progression during standard treatment.

Concomitant administration of radiation with eribulin improves the survival of mice harboring intracerebral glioblastoma

Glioblastoma is the most common and devastating type of malignant brain tumor. We recently found that eribulin suppresses glioma growth in vitro and in vivo and that eribulin is efficiently transferred into mouse brain tumors at a high concentration. Eribulin is a non‐taxane microtubule inhibitor approved for breast cancer and liposarcoma. Cells arrested in M‐phase by chemotherapeutic agents such as microtubule inhibitors are highly sensitive to radiation‐induced DNA damage. Several recent case reports have demonstrated the clinical benefits of eribulin combined with radiation therapy for metastatic brain tumors. In this study, we investigated the efficacy of a combined eribulin and radiation treatment on human glioblastoma cells. The glioblastoma cell lines U87MG, U251MG and U118MG, and SJ28 cells, a patient‐derived sphere culture cell line, were used to determine the radiosensitizing effect of eribulin using western blotting, flow cytometry and clonogenic assay. Subcutaneous and intracerebral glioma xenografts were generated in mice to assess the efficacy of the combined treatment. The combination of eribulin and radiation enhanced DNA damage in vitro. The clonogenic assay of U87MG demonstrated the radiosensitizing effect of eribulin. The concomitant eribulin and radiation treatment significantly prolonged the survival of mice harboring intracerebral glioma xenografts compared with eribulin or radiation alone (P < .0001). In addition, maintenance administration of eribulin after the concomitant treatment further controlled brain tumor growth. Aberrant microvasculature was decreased in these tumors. Concomitant treatment with eribulin and radiation followed by maintenance administration of eribulin may serve as a novel therapeutic strategy for glioblastomas.

Abstract 3117: Eribulin is a novel TERT-targeting inhibitor that penetrates into intracerebrally grown glioblastomas and suppresses their growth in mice

[Introduction] No effective molecular targeting therapy has been clinically developed for patients with glioblastoma (GBM) despite of intense genome analysis. Approximately 60-80% of GBM harbor mutations in the promoter region of TERT that leads to its upregulation, making it the most common single genetic abnormalities in GBM. TERT, a reverse-transcriptase subunit of telomerase, has been an attractive candidate for therapy target because of their observed upregulation in a wide variety of cancers, including GBMs, a phenomenon that presumably helps maintain telomeres for their indefinite proliferation. It has been reported recently that TERT has an RNA-dependent RNA polymerase (RdRP) activity, with which TERT is involved in maintenance of stem cell phenotype and mitotic progression. We have previously identified eribulin as a specific inhibitor of RdRP activity of TERT through drug screening and shown that eribulin suppressed growth of ovarian cancers with high TERT expression. In order to investigate an efficacy of eribulin as a novel TERT-targeted therapy against GBM, we investigated the antitumor effect of eribulin in cultured cell and brain tumor model using GBM cell lines. [Methods] The TERT promoter status was examined in 20 glioma cell lines. Seven cell lines were subjected to in vitro cytotoxicity assay. U87MG was either subcutaneously or intracranially transplanted in athymic mice. Tissue or plasma concentration of eribulin was measured by LC-MS/MS. [Results] All GBM cell lines tested that harbored TERT promoter mutations including U87MG, U251MG, U118MG as well as several patient-derived glioblastoma sphere culture cells were highly sensitive to eribulin, IC50 below 1nM. Intraperitoneal administration of eribulin completely suppressed the growth of U87MG subcutaneous tumor in nude mice, and the RdRP activities in treated tumors were significantly decreased in a dose-dependent manner. In the brain tumor model, a high concentration of eribulin was detected in the brain tumor tissues as early as 15 minutes after intravenous injection of eribulin, which remained stable even 24 hours later when the plasma concentration of eribulin became undetectable. Finally, intraperitoneal administration of eribulin significantly prolonged the survival of mice with intracerebrally transplanted U87MG xenograft (p [Conclusion] Our results showed that eribulin efficiently transfers into brain tumor tissues and has a strong antitumor effect against GBM cells through inhibition of RdRP activity. Eribulin thus appears to be a promising novel TERT-targeting therapeutic agent against GBM. A clinical trial is being scheduled. Citation Format: Masamichi Takahashi, Shunichiro Miki, Yuko Matsushita, Kohei Fukuoka, Yoshiko Maida, Mami Yasukawa, Mitsuhiro Hayashi, Akinobu Hamada, Akitake Mukasa, Ryo Nishikawa, Kenji Tamura, Yoshitaka Narita, Kenkichi Masutomi, Koichi Ichimura. Eribulin is a novel TERT-targeting inhibitor that penetrates into intracerebrally grown glioblastomas and suppresses their growth in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3117. doi:10.1158/1538-7445.AM2017-3117

Intraparenchymal brain lesion biopsy guided by a rigid endoscope and navigation system.

Background: The authors report a continuous case series of navigation-guided rigid endoscopic biopsy via the transcortical route for intraparenchymal brain lesions to assess the feasibility and efficacy of the method. Methods: Thirty-four patients with intraparenchymal brain lesions found on neurovisualization underwent navigation-guided rigid endoscopic biopsy. Most of the preoperative diagnoses were glioma WHO Grade II–IV (16 cases) or malignant lymphoma (15 cases). Intraoperative photodynamic diagnosis and intraoperative pathological diagnosis were used in 28 and 29 cases, respectively. In 2 cases with small and deep lesions, intraoperative magnetic resonance imaging was used for confirming the accuracy of the biopsy point. Results: The sampling accuracy determined by postoperative imaging and the definitive diagnosis ratio were 94% (32 out of 34 cases) and 97% (33 out of 34 cases), respectively. There was no postoperative mortality. In 2 patients, mild postoperative permanent morbidity (5.9%), presumably related to this technique, was observed in the early cases in the current group (34 case series). Conclusion: The method was estimated as safe and feasible for diagnostic tissue sampling of intraparenchymal brain lesions.

Extreme volume expansion of a vestibular schwannoma due to intratumoral hemorrhage after gamma knife radiosurgery

A 48-year-old man with right hemi-facial palsy and cerebellar ataxia was referred to our hospital. Three years and 10 months earlier he had undergone gamma knife radiosurgery (GKRS) at the referring hospital for an 18 mm right vestibular schwannoma. Slight tumor enlargement had been observed on MRI performed at the referring hospital 3 years after the GKRS. On close follow-up after another 6 months an MRI showed an obvious enlargement of the tumor. An MRI on admission revealed an iso-intense mass lesion measuring 36 mm in maximum diameter at the right cerebellopontine angle. A two stage surgery was conducted using a retrosigmoid approach because bleeding from the tumor wall was difficult to control intraoperatively during the first operation. At the second operation, the majority of the tumor capsule had converted to necrotic tissue. A large hematoma cavity was present inside the tumor capsule which explained the rapid increase in size over a short period of time. Near total removal was achieved. Histopathological examination revealed massive intratumoral hemorrhage within a typical vestibular schwannoma with no malignancy. The complication of intratumoral hemorrhage is very rare and the utility of stereotactic radiation surgery/therapy, including GKRS, for vestibular schwannoma is well known. However, we must emphasize that careful follow-up is still required, even after several years.