Usefulness of intraoperative rapid immunohistochemistry in the surgical treatment of brain tumors.

In the treatment of primary central nervous system lymphoma (PCNSL), intraoperative rapid pathological diagnosis can dramatically change the surgical strategy, and more accurate diagnostic methods are required. In April 2020, we adopted intraoperative rapid immunohistochemistry (IHC) in addition to conventional rapid intraoperative diagnosis based on morphological assessment, mainly for patients with PCNSL. Here, we investigate the usefulness and significance of intraoperative rapid IHC based on our initial experience. We performed intraoperative rapid IHC using antibodies for cluster of differentiation (CD)20, CD3, leukocyte common antigen (LCA) and glial fibrillary acidic protein (GFAP) using enzyme-labeled antibody methods in 25 patients, including PCNSL patients, from April 2020 to July 2022. We examined the utility of this approach in determining treatment strategies for brain tumors. Postoperative final pathological diagnoses from paraffin-embedded sections were as follows: diffuse large B-cell lymphoma, 16 cases; glioblastoma, six cases; pilocytic astrocytoma, one case; adenocarcinoma, one case; and inflammatory disorder, one case. The entire process took 32 min and staining for CD20, CD3, LCA, and GFAP was comparable to that using paraffin-embedded sections. In all cases, the results of intraoperative rapid IHC were consistent with final pathological diagnoses from paraffin-embedded sections. In addition, in two cases, the results of conventional intraoperative rapid pathological diagnosis based on morphological assessments using frozen sections were drastically changed by adding intraoperative rapid IHC. Intraoperative rapid IHC contributes to deciding appropriate treatment strategies and facilitating early initiation of chemotherapy for PCNSL. This may allow new therapeutic strategies not only for PCNSL but also for other brain tumors.

Quantitative measurement of peritumoral concentrations of glutamate, N-acetyl aspartate, and lactate on magnetic resonance spectroscopy predicts glioblastoma-related refractory epilepsy.

BACKGROUND: Increased extracellular glutamate is known to cause epileptic seizures in patients with glioblastoma (GBM). However, predicting whether the seizure will be refractory is difficult. The present study investigated whether evaluation of the levels of various metabolites, including glutamate, can predict the occurrence of refractory seizure in GBM by quantitative measurement of metabolite concentrations on magnetic resonance spectroscopy (MRS). METHODS: Forty patients were treated according to the same treatment protocol for primary GBM at Ehime University Hospital between April 2017 and July 2021. Of these patients, 23 underwent MRS to determine concentrations of metabolites, including glutamate, N-acetylaspartate, creatine, and lactate, in the tumor periphery by applying LC-Model. The concentration of each metabolite was expressed as a ratio to creatine concentration. Patients were divided into three groups: Type A, patients with no seizures; Type B, patients with seizures that disappeared after treatment; and Type C, patients with seizures that remained unrelieved or appeared after treatment (refractory seizures). Relationships between concentrations of metabolites and seizure types were investigated. RESULTS: In 23 GBMs, seizures were confirmed in 11 patients, including Type B in four and Type C in seven. Patients with epilepsy (Type B or C) showed significantly higher glutamate and N-acetylaspartate values than did non-epilepsy patients (Type A) (p < 0.05). No significant differences in glutamate or N-acetylaspartate levels were seen between Types B and C. Conversely, Type C showed significantly higher concentrations of lactate than did Type B (p = 0.001). Cutoff values of lactate-to-creatine, glutamate-to-creatine, and N-acetylaspartate-to-creatine ratios for refractory seizure were > 1.25, > 1.09, and > 0.88, respectively. CONCLUSIONS: Extracellular concentrations of glutamate, N-acetylaspartate, and lactate in the tumor periphery were significantly elevated in patients with GBM with refractory seizures. Measurement of these metabolites on MRS may predict refractory epilepsy in such patients and could be an indicator for continuing the use of antiepileptic drugs.

Efficacy and safety of nivolumab in Japanese patients with first recurrence of glioblastoma: an open-label, non-comparative study.

BACKGROUND: An open-label, non-comparative study assessed the efficacy and safety of nivolumab in Japanese patients with first recurrence glioblastoma. METHODS: Patients with first recurrence of histologically confirmed World Health Organization Grade IV glioma, after treatment with temozolomide and radiotherapy, received nivolumab 3 mg/kg every 2 weeks until confirmed disease progression (Response Assessment in Neuro-Oncology criteria) or toxicity. Primary endpoint was 1-year overall survival rate assessed by Bayesian approach. The prespecified efficacy criterion was that the Bayesian posterior probability threshold for exceeding the 1-year overall survival of bevacizumab (34.5%) from the Japanese phase 2 study (JO22506) would be 93%. RESULTS: Of the 50 enrolled patients, 44 (88.0%) had recurrent malignant glioma (glioblastoma, gliosarcoma), and of these, 26 (59.1%) had at least one measurable lesion at baseline. The Bayesian posterior mean 1-year overall survival (90% Bayesian credible intervals) with nivolumab was 54.4% (42.27-66.21), and the Bayesian posterior probability of exceeding the threshold of the 1-year overall survival rate of bevacizumab (34.5%) was 99.7%. Median (90% confidence interval) overall and progression-free survival was 13.1 (10.4-17.7) and 1.5 (1.4-1.5) months, respectively. One partial response was observed (objective response rate 1/26 evaluable patients [3.8%]). Treatment-related adverse event rates were 14.0% for Grade 3-4 and 2.0% for Grade 5; most adverse events resolved and were manageable. CONCLUSIONS: The 1-year overall survival with nivolumab monotherapy in Japanese patients with glioblastoma met the prespecified efficacy criterion. The safety profile of nivolumab was consistent with that observed in other tumor types. CLINICAL TRIAL REGISTRATION: JapicCTI-152967.

Met-PET uptake index for total tumor resection: identification of 11C-methionine uptake index as a goal for total tumor resection including infiltrating tumor cells in glioblastoma.

Glioblastoma multiforme (GBM) is largely due to glioma stem cells (GSCs) that escape from total resection of gadolinium (Gd)-enhanced tumor on MRI. The aim of this study is to identify the imaging requirements for maximum resection of GBM with infiltrating GSCs. We investigated the relationship of tumor imaging volume between MRI and 11C-methionine (Met)-PET and also the relationship between Met uptake index and tumor activity. In ten patients, tumor-to-contralateral normal brain tissue ratio (TNR) was calculated to evaluate metabolic activity of Met uptake areas which were divided into five subareas by the degrees of TNR. In each GBM, tumor tissue was obtained from subareas showing the positive Met uptake. Immunohistochemistry was performed to examine the tumor proliferative activity and existence of GSCs. In all patients, the volume of Met uptake area at TNR ≦ 1.4 was larger than that of the Gd-enhanced area. The Met uptake area at TNR 1.4 beyond the Gd-enhanced tumor was much wider in high invasiveness-type GBMs than in those of low invasiveness type, and survival was much shorter in the former than the latter types. Immunohistochemistry revealed the existence of GSCs in the area showing Met uptake at TNR 1.4 and no Gd enhancement. Areas at TNR > 1.4 included active tumor cells with relatively high Ki-67 labeling index. In addition, it was demonstrated that GSCs could exist beyond the border of Gd-enhanced tumor. Therefore, to obtain maximum resection of GBMs, including infiltrating GSCs, aggressive surgical excision that includes the Met-positive area at TNR 1.4 should be considered.

Intracranial anaplastic solitary fibrous tumor/hemangiopericytoma: immunohistochemical markers for definitive diagnosis.

Intracranial anaplastic hemangiopericytoma (AHPC) is a rare and malignant subset of solitary fibrous tumor/hemangiopericytoma (SFT/HPC) as per the WHO 2016 Classification of Tumors of the Central Nervous System. AHPC portends a poor prognosis and is associated with higher rates of recurrence/metastasis in comparison with SFT/HPC. Accordingly, it is critical to continue to define the clinical course of patients with AHPC and in so doing further refine clinicopathologic/immunohistochemical (IHC) criteria needed for definitive diagnosis. Herein, we describe clinical/histological characteristics of six patients with AHPC. In addition, we reviewed and analyzed the expression of various IHC markers reported within the literature (i.e., a total of 354 intracranial SFT/HPCs and 460 meningiomas). Histologically, tumors from our six patients were characterized by a staghorn-like vascular pattern, mitotic cells, and strong nuclear atypia. Immunohistochemically, all tumors displayed positive nuclear staining for STAT6; other markers, including CD34 and Bcl-2, were expressed only in three patients. Analysis of IHC expression patterns for SFT/HPC and meningioma within the literature revealed that nuclear expression of STAT6 had the highest specificity (100%) for SFT/HPC, followed by ALDH1 (97.2%) and CD34 (93.6%). Of note, SSTR2A (95.2%) and EMA (85%) displayed a high specificity for meningioma. Anaplastic SFT/HPC is a tumor with poor prognosis that is associated with higher rates of recurrence and metastasis in comparison with SFT/HPC. Given that anaplastic SFT/HPC requires more aggressive treatment than meningioma despite of a similar presentation on imaging, it is crucial to be able to distinguish between these tumors.

Tricks and traps of ICG endoscopy for effectively applying endoscopic transsphenoidal surgery to pituitary adenoma.

Differentiating tumor from normal pituitary gland is very important for achieving complete resection without complications in endoscopic endonasal transsphenoidal surgery (ETSS) for pituitary adenoma. To facilitate such surgery, we investigated the utility of indocyanine green (ICG) fluorescence endoscopy as a tool in ETSS. Twenty-four patients with pituitary adenoma were enrolled in the study and underwent ETSS using ICG endoscopy. After administering 12.5 mg of ICG twice an operation with an interval > 30 min, times from ICG administration to appearance of fluorescence on vital structures besides the tumor were measured. ICG endoscopy identified vital structures by the phasic appearance of fluorescent signals emitted at specific consecutive elapsed times. Elapsed times for internal carotid arteries did not differ according to tumor size. Conversely, as tumor size increased, elapsed times for normal pituitary gland were prolonged but those for the tumor were reduced. ICG endoscopy revealed a clear boundary between tumors and normal pituitary gland and enabled confirmation of no more tumor. ICG endoscopy could provide a useful tool for differentiating tumor from normal pituitary gland by evaluating elapsed times to fluorescence in each structure. This method enabled identification of the boundary between tumor and normal pituitary gland under conditions of a low-fluorescence background, resulting in complete tumor resection with ETSS. ICG endoscopy will contribute to improve the resection rate while preserving endocrinological functions in ETSS for pituitary adenoma.

The effect of anticoagulants on delayed bleeding after colorectal endoscopic submucosal dissection.

BACKGROUND AND AIMS: The withdrawal of antithrombotic therapy from patients at high risk of thromboembolism is controversial. Previously, treatment with anticoagulants, such as warfarin and dabigatran, was recommended for heparin bridge therapy (HBT) during endoscopic submucosal dissection (ESD). However, HBT is associated with a high risk of bleeding during and after ESD. This study aimed to investigate the clinical outcomes of colorectal ESD in patients treated with warfarin and direct oral anticoagulants (DOAC). METHODS: This study included 412 patients with superficial colorectal neoplasms that were resected by ESD between June 2010 and June 2018. The patients were classified into two groups: without antithrombotics (n = 286) and with anticoagulants (n = 51). The anticoagulants group was further divided into two groups: warfarin (n = 26) and DOAC (n = 25). RESULTS: Among all patients, delayed bleeding occurred in 35 (8.5% [35/412]) patients. The bleeding rate in the anticoagulants group (11.8% [6/51]) was higher than that in the group without antithrombotics (6.6% [19/286]), but the difference was not statistically significant (P = 0.240). The bleeding rate in the DOAC group (16.0% [4/25]) was higher than that in the warfarin group (7.7% [2/26]), but the difference was not statistically significant (P = 0.419). All delayed bleeding was successfully managed with endoscopic hemostasis. Thromboembolic events were not observed in any patients. CONCLUSIONS: The bleeding rate with anticoagulants was relatively high. However, all bleeding events with anticoagulants were minor and clinically controllable. Colorectal ESD with DOAC and warfarin may be feasible and acceptable.

Endoscopic transpapillary gallbladder drainage for acute cholecystitis is feasible for patients receiving antithrombotic therapy.

OBJECTIVES: Patients with acute cholecystitis receiving antithrombotic therapy (ATT) have an increased risk of bleeding complications during surgery and percutaneous drainage. Endoscopic transpapillary gallbladder drainage (ETGBD) is recommended for such cases; however, evidence is limited. To investigate this issue further, we performed a retrospective multicenter study. METHODS: One hundred thirty patients with acute cholecystitis who underwent ETGBD were enrolled. They were divided into an ATT group (continuation of ATT on the day of the procedure and/or heparin substitution) and a Non-ATT group (discontinuation or no use of ATT). The primary outcome was bleeding complication rate, and the secondary outcomes were technical success rate, clinical success rate and total complication rate. RESULTS: Eighty-three patients were enrolled in the ATT group, and 47 were enrolled in the Non-ATT group. In the ATT group, 42.2% continued multi-agent ATT. No bleeding complications occurred in either group. There were no significant differences between the ATT and Non-ATT groups in the technical success rate (84.3% vs 89.4%, P = 0.426 respectively) or the clinical success rate (97.1% vs 100%, P = 0.259, respectively). The overall early complication rate was 3.1% (4/130): mild pancreatitis (n = 3) and cholangitis (n = 1). Stent dysfunction was found in 10.9% of patients (at 196 days on average), and the 12-month stent patency rate was 69.0%. CONCLUSIONS: No significant difference was found in the bleeding complication rate between ETGBD with and without ATT. ETGBD may be an ideal drainage method for patients with acute cholecystitis receiving ATT.

Saline-pocket endoscopic submucosal dissection for superficial colorectal neoplasms: a randomized controlled trial (with video).

BACKGROUND AND AIMS: Colorectal endoscopic submucosal dissection (ESD) is a time-consuming procedure because of the technical difficulty. The newly developed saline-pocket ESD (SP-ESD) provides a clearer view and better traction of the submucosal layer compared with the standard ESD with gas insufflation (S-ESD). This study aimed to prospectively compare the efficacy and safety between S-ESD and SP-ESD in patients with superficial colorectal neoplasms (SCNs). METHODS: From April 2017 to November 2018, 95 patients with SCNs ≥20 mm in diameter were prospectively and randomly enrolled. Four patients were excluded because of an incomplete ESD procedure. Patients were finally allocated to 2 groups, S-ESD with 45 patients and SP-ESD with 46 patients. The primary outcome was dissection speed. Secondary outcomes were ESD procedure time, en bloc and complete resection rates, perforation rate, and adverse effects. RESULTS: Median dissection speed was significantly faster in the SP-ESD than the S-ESD group (20.1 mm2/min [range, 17.3-28.1] vs 16.3 mm2/min [range, 11.4-19.8]; P < .001). Median procedure time was significantly shorter in the SP-ESD than the S-ESD group (29.5 minutes [range, 22.3-44] vs 41 minutes [range, 31-55]; P < .001). The en bloc and complete resection rates were 100% in both groups. No perforations occurred among patients. The volume of saline solution used in the SP-ESD group was significantly greater than that in the S-ESD group (200 mL [range, 120-250] vs 150 mL [range, 100-200]; P = .016). CONCLUSIONS: SP-ESD improved dissection speed and procedure time compared with S-ESD. SP-ESD may be an alternative method for resection of SCNs. (Clinical trial registration number: UMIN 000026317.).

Electrospray Deposition of {200} Oriented Regular-Assembly BaTiO3 Nanocrystal Films under an Electric Field.

Highly oriented, regularly assembled nanocrystalline films have recently emerged as attractive new functional materials. In this study, we deposited a BaTiO3 (BT) nanocube dispersion on a Si substrate by electrospraying, resulting in a dense, regularly assembled BT nanocrystalline film. X-ray diffraction analysis revealed that applying a voltage between the electrospray nozzle and the Si substrate during electrospraying caused the BT nanocubes to form a regular array in the 200 plane aligned perpendicularly to the substrate. The volume fraction of BT nanocubes in the 200 plane in the assembly was estimated by the orientation distribution function analysis to be about 50%. The formation of this regularly assembled layer was determined to be linked to the interaction between the vaporized solvent and the substrate, enabled by the enhanced wettability under the electric field. Electrospray deposition has potential applications in the manufacture of nanocrystalline assembled films for nanofunctional devices.

Water-pocket endoscopic submucosal dissection for superficial gastric neoplasms (with video).

BACKGROUND AND AIMS: During endoscopic submucosal dissection (ESD), a clear view is essential for precise dissection of the appropriate submucosal layer. Some advantages have been reported for underwater techniques of endoscopic resection in comparison with the gas insufflation method. We have developed a new ESD method with the creation of a local water pocket (WP) that provides a clear view in the dissection field. Therefore, we aimed to investigate the feasibility and safety of WP-ESD for superficial gastric neoplasms. METHODS: We prospectively recruited 50 patients with gastric neoplasms (early gastric cancer or gastric adenomas) between April 2017 and December 2017. Among them, 48 patients were treated with the WP-ESD technique. The patients undergoing WP-ESD were compared with 48 patients treated with standard ESD (S-ESD) who were selected by propensity score matching. The primary outcome was the ESD procedure time. RESULTS: Total procedure time was significantly shorter in the WP-ESD group than in the S-ESD group (median [interquartile range], 27.5 [19-45] minutes vs 41 [29.8-69] minutes; P < .001). Similarly, the dissection speed was significantly greater in the WP-ESD group than in the S-ESD group (median [interquartile range], 22.5 [16.8-35.3] mm2/min vs 17.3 [12.7-22.1] mm2/min; P < .001). The rates of complete en bloc resection in the WP-ESD group and the S-ESD group were 97.9% and 95.8%, respectively (P > .99). There were no perforations in either group. CONCLUSION: WP-ESD was associated with a shorter procedure time than S-ESD. WP-ESD may provide an alternative method for resection of superficial gastric neoplasms. (Clinical trial registration number: UMIN 000030266.).

Valproic acid reduces hair loss and improves survival in patients receiving temozolomide-based radiation therapy for high-grade glioma.

PURPOSE: Valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, is also used to manage seizures in glioblastoma patients. HDAC inhibitors can protect normal cells and tissues from the deleterious effects of radiotherapy, and VPA is reported to improve the survival of glioblastoma patients receiving chemoradiation therapy. VPA also promotes hair growth, and thus has the potential to reduce the radiotherapy side effect of hair loss while improving the survival of patients with glioblastoma. The purpose of this study was to determine whether VPA use during radiotherapy for high-grade glioma is associated with decreased side effects of radiotherapy and an improvement in overall survival (OS) and progression-free survival (PFS). METHODS: Medical records of 112 patients with high-grade glioma were retrospectively reviewed. We grouped patients by VPA use or non-use during radiotherapy, and evaluated hair loss, OS, and PFS. RESULTS: The radiation dose and fractionation at the onset of hair loss were 4 Gy and two fractions higher, respectively, in the VPA group compared with the VPA non-use group (P < 0.01). Median OS was 42.2 and 20.3 months in the VPA use and non-use groups, respectively (P < 0.01; hazard ratio [HR], 0.36; 95% confidence interval [CI], 0.18-0.74). Median PFS was 22.7 and 11.0 months in the VPA use and non-use groups, respectively (P = 0.099; HR, 0.62; 95% CI, 0.36-1.09). CONCLUSIONS: VPA use during radiotherapy for glioma is associated with delayed hair loss and improvement in survival. Hair loss prevention benefits patients suffering from the deleterious effects of radiation.

Evaluation of serial changes on computed tomography and magnetic resonance imaging after implantation of carmustine wafers in patients with malignant gliomas for differential diagnosis of tumor recurrence.

Carmustine wafers are approved for localized treatment of malignant glioma. In this study, overall changes in computed tomography (CT) and magnetic resonance (MR) images of malignant glioma patients treated with carmustine wafer implantation were evaluated. The subjects were 25 patients undergoing craniotomy for malignant glioma resection and carmustine wafer implantation. Changes in the appearance of wafers, the resection cavity, and the adjacent parenchyma on CT and MR imaging were evaluated retrospectively. On CT, the wafers changed from an initially high-dense to an iso-dense appearance. All MR studies showed a low-intense wafer within 2 days. The wafers changed to a high- or iso-intense appearance on fluid attenuated inversion recovery and T1-weighted imaging, whereas they changed to an iso- to low-intense appearance on T2-weighted imaging. Gas in the cavity increased gradually after surgery, achieved a peak at 1 week postoperatively, and then disappeared in 1-3 months. Increased volume of the resection cavity was observed in 48% of patients. Regarding changes in the adjacent parenchyma, obvious contrast enhancement at the wall of the resection cavity was seen in 91% of cases at 1 month, but this disappeared gradually. Edema around the resection cavity was increased in 7 patients (28%), of whom only two experienced symptoms due to edema. We conclude that these radiological changes after carmustine wafer implantation should be carefully followed up, because these changes can easily be mistaken for infectious disease or recurrent tumors.

Synthesis of Copper-Antimony-Sulfide Nanocrystals for Solution-Processed Solar Cells.

The p-type nanocrystals (NCs) of copper-based chalcogenides, such as CuInSe2 and Cu2ZnSnS4, have attracted increasing attention in photovoltaic applications due to their potential to produce cheap solution-processed solar cells. Herein, we report the synthesis of copper-antimony-sulfide (CAS) NCs with different crystal phases including CuSbS2, Cu3SbS4, and Cu12Sb4S13. In addition, their morphology, crystal phase, and optical properties were characterized using transmission electron microscopy, X-ray diffractometry, UV-vis-near-IR spectroscopy, and photoemission yield spectroscopy. The morphology, crystal phase, and electronic structure were significantly dependent on the chemical composition in the CAS system. Devices were fabricated using particulate films consisting of CAS NCs prepared by spin coating without a high-temperature treatment. The CAS NC-based devices exhibited a diode-like current-voltage characteristic when coupled with an n-type CdS layer. In particular, the CuSbS2 NC devices exhibited photovoltaic responses under simulated sunlight, demonstrating its applicability for use in solution-processed solar cells.

Surgical results of tumor resection using tractography-integrated navigation-guided fence-post catheter techniques and motor-evoked potentials for preservation of motor function in patients with glioblastomas near the pyramidal tracts.

The current optimal surgery for glioblastomas (GBMs) near the pyramidal tract (PT) is to remove as much tumor as possible and to preserve motor function. The purpose of this study is to investigate the usefulness of tractography-integrated navigation-guided fence-post catheter techniques and motor-evoked potentials (MEPs) for preserving postoperative motor function after GBM surgery. We retrospectively examined 49 patients who underwent resection for GBM near the PT. Diffusion tensor (DT) imaging-based tractography of the PT was performed preoperatively and integrated into the navigation system. When possible, silicon catheters were used as "fence-posts" and were inserted along the tumor boundaries, avoiding the PT, before tumor removal using the navigation system (fence-post catheter techniques). Cortical and subcortical MEPs were also monitored during resection of the tumor. Fence-post catheter techniques using a tractography-integrated navigation system were used in 45 of 49 patients. This technique enabled placement of the catheters, avoided the motor pathways, and allowed easier resection of the tumors. Tumors near the PT were resected using subcortical and cortical MEPs. The amplitudes of cortical MEPs after tumor removal were maintained at over 33 % of those obtained before resection. Thirty-six patients showed obvious responses of subcortical MEPs at ≤20 mA. The degree of resection was gross total in 21 patients, subtotal in 21, and partial in seven. One month after surgery, only one patient showed worsened motor function. Therefore, fence-post catheter techniques using a tractography-integrated navigation system and MEPs may contribute to preserving motor function after surgery for GBMs that are near the PT.

Berberine as a potential enhancer for 5-ALA-mediated fluorescence in glioblastoma: increasing detectability of infiltrating glioma stem cells to optimize 5-ALA-guided surgery.

OBJECTIVE: The prognosis of glioblastoma (GBM) correlates with residual tumor volume after surgery. In fluorescence-guided surgery, 5-aminolevulinic acid (ALA) has been used to maximize resection while avoiding neurological morbidity. However, not all tumor cells, particularly glioma stem cells (GSCs), display 5-ALA-mediated protoporphyrin IX (PpIX) fluorescence (5-ALA fluorescence). The authors searched for repositioned drugs that affect mitochondrial functions and energy metabolism, identifying berberine (BBR) as a potential enhancer of 5-ALA fluorescence. In this study, they investigated whether BBR can enhance 5-ALA fluorescence in GSCs and whether BBR can be applied to clinical practice as a 5-ALA fluorescence enhancer. METHODS: The effects of BBR on 5-ALA fluorescence in glioma and GSCs were evaluated by flow cytometry (fluorescence-activated cell sorting [FACS]) analysis. As 5-ALA is metabolized for heme synthesis, the effects of BBR on mRNA expressions of 7 enzymes in the heme-synthesis pathway were analyzed. Enzymes showing significantly higher expression than control in all cells were identified and protein analysis was performed. To examine clinical availability, the detectability and cytotoxicity of BBR in tumor-transplanted mice were analyzed. RESULTS: Fluorescence microscopy revealed much more intense 5-ALA fluorescence in both GSCs and non-stem cells with 5-ALA and BBR than with 5-ALA alone. FACS showed that BBR greatly enhanced 5-ALA fluorescence compared with 5-ALA alone, and enhancement was much higher for GSCs than for glioma cells. Among the 7 enzymes examined, BBR upregulated mRNA expressions of ALA synthetase 1 (ALAS1) more highly in all cells, and activated ALAS1 through deregulating ALAS1 activity inhibited by the negative feedback of heme. An in vivo study showed that 5-ALA fluorescence with 5-ALA and BBR was significantly stronger than with 5-ALA alone, and the sensitivity and specificity of BBR-enhanced fluorescence were both 100%. In addition, BBR did not show any cytotoxicity for normal brain tissue surrounding the tumor mass. CONCLUSIONS: BBR enhanced 5-ALA-mediated PpIX fluorescence by upregulating and activating ALAS1 through deregulation of negative feedback inhibition by heme. BBR is a clinically used drug with no side effects. BBR is expected to significantly augment fluorescence-guided surgery and photodynamic therapy.

Clinical utility of new bone imaging using zero-echo-time sequence in neurosurgical procedures: Can zero-echo-time be used in clinical practice in neurosurgery?

PURPOSE: The purpose of this study was to evaluate the clinical usefulness of zero-echo-time (ZTE)-based magnetic resonance imaging (MRI) in planning the optimum surgical approach and applying ZTE for anatomical guidance during transcranial surgery. METHODS: Eleven of 26 patients who underwent transcranial surgery and carotid endarterectomy and in whom ZTE-based MRI and magnetic resonance angiography (MRA) data were obtained were analyzed by creating ZTE/MRA fusion images and 3D ZTE-based MRI models. We examined whether these images and models can be substituted for computed tomography imaging for neurosurgical procedures. Furthermore, the clinical usability of the 3D ZTE-based MRI models was evaluated by comparing them with actual surgical views. RESULTS: Zero-echo-time/MRA fusion images and 3D ZTE-based MRI models clearly illustrated the cranial and intracranial morphology without radiation exposure or the use of iodinated contrast medium. The models allowed determination of the optimum surgical approach to cerebral aneurysms, brain tumors near the brain surface, and cervical internal carotid artery stenosis by visualizing the relationship of lesions with adjacent bone structures. However, ZTE-based MRI did not provide useful information for surgery for skull base lesions such as vestibular schwannoma because bone structures of the skull base often include air components, which cause signal disturbance in MRI. CONCLUSIONS: Zero-echo-time sequences on MRI allowed distinct visualization of not only bone but also vital structures around the lesion. This technology has low invasiveness for patients and was useful for preoperative planning and guidance of the optimum approach during surgery in a subset of neurosurgical diseases.

What is the Best Preoperative Quantitative Indicator to Differentiate Primary Central Nervous System Lymphoma from Glioblastoma?

BACKGROUND: The role of surgery in primary central nervous system lymphoma (PCNSL) is to allow pathological diagnosis from tumor biopsy. However, PCNSL is often difficult to distinguish from other tumors, particularly glioblastoma multiforme (GBM). Quantitative evaluations to facilitate differentiation between PCNSL and GBM would be useful. Here, we investigated the best examinations for exact differentiation of PCNSL from GBM among preoperative examinations, including imaging studies and tumor markers. METHODS: Various examinations were performed for 68 patients with PCNSL , including serum soluble interleukin 2 receptor, ß2-microglobulin (MG) in cerebrospinal fluid (CSF), diffusion-weighted imaging, 11C-methionine-positron emission tomography (PET), and 18F-fluorodeoxyglucose (FDG)-PET. These results were compared with findings from 28 patients with consecutive GBM who underwent the same examinations to evaluate the utility and accuracy of different investigations. RESULTS: CSF ß2-MG ≥2.0 mg/L was relatively specific for PCNSL, offering 95.0% sensitivity and 85.7% specificity. Tumor-to-contralateral normal brain tissue ratio ≥2.4 on 18F-FDG-PET was also quite specific for PCNSL, offering 83.8% sensitivity and 95.2% specificity. No other examinations displayed any significant differences in quantitative differential markers between PCNSL and GBM. CONCLUSIONS: Both ß2-MG ≥2.0 mg/dL in CSF and tumor-to-contralateral normal brain tissue ratio ≥2.4 from 18F-FDG-PET allow quantitative differentiation of PCNSL from GBM, potentially representing clinically useful indicators. These findings could lead to innovative methods for differentiating PCNSL from GBM as well as new treatment strategies for other brain tumors.

Identification of CD44 as a Reliable Biomarker for Glioblastoma Invasion: Based on Magnetic Resonance Imaging and Spectroscopic Analysis of 5-Aminolevulinic Acid Fluorescence.

Recurrent glioblastoma multiforme (GBM) is largely attributed to peritumoral infiltration of tumor cells. As higher CD44 expression in the tumor periphery correlates with higher risk of GBM invasion, the present study analyzed the relationship between CD44 expression and magnetic resonance imaging (MRI)-based invasiveness of GBM on a large scale. We also quantitatively evaluated GBM invasion using 5-aminolevulinic acid (5-ALA) spectroscopy to investigate the relationship between CD44 expression and tumor invasiveness as evaluated by intraoperative 5-ALA intensity. Based on MRI, GBM was classified as high-invasive type in 28 patients and low-invasive type in 22 patients. High-invasive type expressed CD44 at a significantly higher level than low-invasive type and was associated with worse survival. To quantitatively analyze GBM invasiveness, the relationship between tumor density in the peritumoral area and the spectroscopic intensity of 5-ALA was investigated. Spectroscopy showed that the 5-ALA intensity of infiltrating tumor cells correlated with tumor density as represented by the Ki-67 staining index. No significant correlation between CD44 and degree of 5-ALA-based invasiveness of GBM was found, but invasiveness of GBM as evaluated by 5-ALA matched the classification from MRI in all except one case, indicating that CD44 expression at the GBM periphery could provide a reliable biomarker for invasiveness in GBM.