Cell function and metabolic state are coupled independently of hypoxia, and glucose metabolic pathways are causatively involved in regulating "go or grow" cellular programs.

OBJECTIVEIn patients with suspected diffusely infiltrating low-grade gliomas (LGG), the prognosis is dependent especially on extent of resection and precision of tissue sampling. Unfortunately, visible 5-aminolevulinic acid (5-ALA) fluorescence is usually only present in high-grade gliomas (HGGs), and most LGGs cannot be visualized. Recently, spectroscopic probes were introduced allowing in vivo quantitative analysis of intratumoral 5-ALA–induced protoporphyrin IX (PpIX) accumulation. The aim of this study was to intraoperatively investigate the value of visible 5-ALA fluorescence and quantitative PpIX analysis in suspected diffusely infiltrating LGG.METHODSPatients with radiologically suspected diffusely infiltrating LGG were prospectively recruited, and 5-ALA was preoperatively administered. During resection, visual fluorescence and absolute tissue PpIX concentration (CPpIX) measured by a spectroscopic handheld probe were determined in different intratumoral areas. Subsequently, corresponding tissue samples were safely collected for histopathological analysis. Tumor diagnosis was established according to the World Health Organization 2016 criteria. Additionally, the tumor grade and percentage of tumor cells were investigated in each sample.RESULTSAll together, 69 samples were collected from 22 patients with histopathologically confirmed diffusely infiltrating glioma. Visible fluorescence was detected in focal areas in most HGGs (79%), but in none of the 8 LGGs. The mean CPpIX was significantly higher in fluorescing samples than in nonfluorescing samples (0.693 μg/ml and 0.008 μg/ml, respectively; p < 0.001). A significantly higher mean percentage of tumor cells was found in samples with visible fluorescence compared to samples with no fluorescence (62% and 34%, respectively; p = 0.005), and significant correlation of CPpIX and percentage of tumor cells was found (r = 0.362, p = 0.002). Moreover, high-grade histology was significantly more common in fluorescing samples than in nonfluorescing samples (p = 0.001), whereas no statistically significant difference in mean CPpIX was noted between HGG and LGG samples. Correlation between maximum CPpIX and overall tumor grade was highly significant (p = 0.005). Finally, 14 (40%) of 35 tumor samples with no visible fluorescence and 16 (50%) of 32 LGG samples showed significantly increased CPpIX (cutoff value: 0.005 μg/ml).CONCLUSIONSVisible 5-ALA fluorescence is able to detect focal intratumoral areas of malignant transformation, and additional quantitative PpIX analysis is especially useful to visualize mainly LGG tissue that usually remains undetected by conventional fluorescence. Thus, both techniques will support the neurosurgeon in achieving maximal safe resection and increased precision of tissue sampling during surgery for suspected LGG.Clinical trial registration no.: NCT01116661 (clinicaltrials.gov)

This epidemiological study of a small, but clinically well-annotated patient cohort fails to support the assumption that the strong increase of bevacizumab use since 2010 improved survival in glioblastoma although clinical benefit associated with decreased steroid use may have been achieved.

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Interstitial photodynamic therapy (iPDT) using 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) as a cytotoxic photosensitizer could be a feasible treatment option for malignant gliomas. In a monocentric cohort of consecutive patients treated between 2006 and 2018, a risk profile analysis of salvage iPDT for local malignant glioma recurrences and associated outcome measures are presented here. It was considered indicated in patients with circumscribed biopsy-proven malignant glioma recurrences after standard therapy, if not deemed eligible for safe complete resection. A 3D treatment-planning software was used to determine the number and suitable positions of the cylindrical diffusing fibers placed stereotactically to ensure optimal interstitial irradiation of the target volume. Outcome measurements included the risk profile of the procedure, estimated time-to-treatment-failure (TTF), post-recurrence survival (PRS) and prognostic factors. Forty-seven patients were treated, of which 44 (median age, 49.4 years, range, 33.4–87.0 years, 27 males) could be retrospectively evaluated. Recurrent gliomas included 37 glioblastomas (WHO grade IV) and 7 anaplastic astrocytomas (WHO grade III). Thirty (68.2%) tumors were O-6-methylguanine-DNA methyltransferase (MGMT)-methylated, 29 (65.9%)—isocitrate dehydrogenase (IDH)-wildtype. Twenty-six (59.1%) patients were treated for their first, 9 (20.5%)—for their second, 9 (20.5%)—for the third or further recurrence. The median iPDT target volume was 3.34 cm3 (range, 0.50–22.8 cm3). Severe neurologic deterioration lasted for more than six weeks in one patient only. The median TTF was 7.1 (95% confidence interval (CI), 4.4–9.8) months and the median PRS was 13.0 (95% CI, 9.2–16.8) months. The 2- and 5-year PRS rates were 25.0% and 4.5%, respectively. The treatment response was heterogeneous and not significantly associated with patient characteristics, treatment-related factors or molecular markers. The promising outcome and acceptable risk profile deserve further prospective evaluation particularly to identify mechanisms and prognostic factors of favorable treatment response.

1.Increased glycolysis is linked with increased cell migration and invasion in glioblastoma cells. 2.The glycolysis enzyme GPI/AMF may serve as a target for antimetabolic and anti-invasive therapy. 3.Despite reducing tumor invasion, GPI/AMF targeting may have unwanted growth stimulatory effects.

PURPOSE: To explore a prognostic or predictive role of magnetic resonance imaging (MRI) and O-(2-18 F-fluoroethyl)-L-tyrosine ( 18 FET) positron emission tomography (PET) parameters for outcome in the randomized multi-center trial ARTE that compared bevacizumab plus radiotherapy with radiotherpay alone in elderly patients with glioblastoma. EXPERIMENTAL DESIGN: Patients with isocitrate dehydrogenase wild-type glioblastoma aged 65 years or older were included in this post-hoc analysis. Tumor volumetric and apparent diffusion coefficient (ADC) analyses of serial MRI scans from 67 patients and serial 18 FET-PET tumor-to-brain intensity ratios (TBR) from 31 patients were analyzed blinded for treatment arm and outcome. Multivariate Cox regression analysis was done to account for established prognostic factors and treatment arm. RESULTS: Overall survival benefit from bevacizumab plus radiotherapy compared to radiotherapy alone was observed for larger pre-treatment MRI contrast-enhancing tumor (hazard ratio [HR] per cm 3 0.94, 95% confidence interval [CI] 0.89-0.99) and for higher ADC (HR 0.18, CI 0.05-0.66). Higher 18 FET-TBR on pre-treatment PET scans was associated with inferior overall survival in both arms. Response assessed by standard MRI-based RANO criteria was associated with overall survival in the bevacizumab plus radiotherapy arm by trend only (p=0.09). High 18 FET-TBR of non-contrast-enhancing tumor portions during bevacizumab therapy was associated with inferior overall survival on multivariate analysis (HR 5.97,. CONCLUSION: Large pre-treatment contrast-enhancing tumor mass and higher ADC identify patients who may experience a survival benefit from bevacizumab plus radiotherapy. Persistent 18 FET-PET signal of no longer contrastenhancing tumor after concomitant bevacizumab plus radiotherapy suggests pseudoresponse and predicts poor outcome. TRIAL REGISTRATION: NCT01443676.

Objective To evaluate the diagnostic accuracy and safety of extended stereotactic brain biopsy (ESBB) in a single center cohort with suspected primary angiitis of the central nervous system (PACNS). Methods A standardized stereotactic biopsy targeting MRI-positive lesions and collecting samples from the meninges and the cortex as well as from the white matter was performed in 23 patients with clinically suspected PACNS between 2010 and 2017. The relationship between biopsy yield and clinical characteristics, cerebrospinal fluid parameters, MR-imaging, time point of biopsy and exact localization of biopsy as well as number of tissue samples were examined. Results PACNS was confirmed in 7 of 23 patients (30.4%). Alternative diagnoses were identified in 7 patients (30%). A shorter time period between the onset or worsening of symptoms ( p = 0.018) and ESBB significantly increased the diagnostic yield. We observed only minor and transient postoperative complications in 3 patients (13.0%). ESBB led to a direct change of the therapeutic regime in 13 of 23 patients (56.5%). Careful neuropathological analysis furthermore revealed that cortical samples were crucial in obtaining a diagnosis. Conclusion ESBB is a safe approach with good feasibility, even in critically ill patients, and high diagnostic accuracy in patients with suspected PACNS changing future therapies in 13 of 23 patients (56.5%). Early biopsy after symptom onset/worsening is crucial and (sub)acute MRI-lesions should be targeted with a particular need for biopsy samples from the cortical layer.