Intraoperative Radiotherapy in Newly Diagnosed Glioblastoma (INTRAGO): An Open-Label, Dose-Escalation Phase I/II Trial.

BACKGROUND: The median time to recurrence of glioblastoma (GB) following multimodal treatment is ∼7 mo. Nearly all cancers recur locally, suggesting that augmenting local treatments may improve outcomes. OBJECTIVE: To investigate whether intraoperative radiotherapy (IORT) to the resection cavity is safe and effective. METHODS: INTRAGO was a phase I/II trial to evaluate the safety and tolerability of IORT with 20 to 40 Gy of low-energy photons in addition to standard radiochemotherapy (ClinicalTrials.gov ID, NCT02685605). The primary endpoint was safety as per occurrence of dose-limiting toxicities. Secondary endpoints were progression-free survival (PFS) and overall survival (OS). We also performed an exploratory analysis of the local PFS (L-PFS), defined as recurrence within 1 cm of the treated margin. RESULTS: Fifteen patients were treated at 3 dose levels. Of these, 13 underwent incomplete resection, 6 had unresected satellites, and 3 did not receive per-protocol treatment (PPT). The MGMT promoter was unmethylated in 10 patients. The median follow-up was 13.8 mo. The majority of grade 3 to 5 adverse events were deemed unrelated to IORT. Five cases of radionecrosis were observed, 2 were classified as grade 3 events. Other grade 3 events judged related to radiotherapy (external-beam radiotherapy and/or IORT) were wound dehiscence (n = 1), CSF leakage (n = 1), cyst formation (n = 1). No IORT-related deaths occurred. The median PFS was 11.2 mo (95% confidence interval [CI]: 5.4-17.0) for all patients and 11.3 mo (95% CI: 10.9-11.6) for those receiving PPT. The median L-PFS was 14.3 mo (95% CI: 8.4-20.2) for all patients and 17.8 mo (95% CI: 9.7-25.9) for those receiving PPT. The median OS was 16.2 mo (95% CI: 11.1-21.4) for all patients and 17.8 mo (95% CI: 13.9-21.7) for those receiving PPT. CONCLUSION: These data suggest that IORT is associated with manageable toxicity. Considering the limitations of a 15-patient phase I/II trial, further studies aimed at assessing an outcome benefit are warranted.

Ulnar nerve integrity predicts 1-year outcome in cervical spinal cord injury.

BACKGROUND: Accurate predictors of neurological recovery after cervical spinal cord injury are needed. Particularly, to tailor adequate rehabilitation plans. However, objective and quantifiable predictors are sparse. METHODS: Within the prospective European Multicenter Study about Spinal Cord Injury (EMSCI) registry, cervical spinal cord injury patients are monitored at fixed follow up visits (2, 4, 12, 24, and 48 weeks after injury) clinically and with ulnar nerve electroneurography. Associations of ulnar nerve compound muscle action potential amplitudes (CMAP) with American Spinal Cord Injury Association (ASIA) impairment scale (AIS) grades over time were analyzed using linear mixed modeling. Applying logistic regression, the prognostic value of within 4-week ulnar nerve CMAP for 1-year AIS was analyzed. To account for missing data, (1) last observation carried forward and (2) multiple imputation methods were applied. For model derivation, our centers' cohort (EMSCI-HD) was analyzed. For model validation the cohort of other centers (EMSCI-nonHD) was used. RESULTS: In the EMSCI-HD cohort, the median age (interquartile range (IQR)) was 52 (34-67) years. 58% were male. The initial AIS distribution was: A = 31%, B = 17%, C = 30%, and D = 22%). In the EMSCI-nonHD cohort, the median age was 49 (32-65) years. Compared to the EMSCI-HD cohort more patients were male (79%, p = 0.0034). The AIS distribution was: A = 33%, B = 13%, C = 21%, and D = 33%).In complete-case mixed model analyses (EMSCI-HD: n = 114; EMSCI-nonHD: n = 508) higher ulnar nerve CMAP were associated with better AIS grades over the entire follow up period. In complete-case logistic regression (EMSCI-HD: n = 90; EMSCI-nonHD: n = 444) higher ulnar nerve CMAP was an independent predictor of better AIS grades. The odds ratio for within 4-week ulnar nerve CMAP to predict 1-year AIS grade D versus A-C in the EMSCI-HD cohort was 1.24 per millivolt (confidence interval 1.07-1.44). The model was validated in an independent cervical spinal cord injury (EMSCI-nonHD) cohort (odds ratio 1.09, confidence interval 1.03-1.17). CONCLUSIONS: In cervical spinal cord injury, the consideration of early ulnar nerve CMAP improves prognostic accuracy, which is of particular importance in patients with clinical grading uncertainties.

Oxygen extraction fraction mapping at 3 Tesla using an artificial neural network: A feasibility study.

PURPOSE: The oxygen extraction fraction (OEF) is an important biomarker for tissue-viability. MRI enables noninvasive estimation of the OEF based on the blood-oxygenation-level-dependent (BOLD) effect. Quantitative OEF-mapping is commonly applied using least-squares regression (LSR) to an analytical tissue model. However, the LSR method has not yet become clinically established due to the necessity for long acquisition times. Artificial neural networks (ANNs) recently have received increasing interest for robust curve-fitting and might pose an alternative to the conventional LSR method for reduced acquisition times. This study presents in vivo OEF mapping results using the conventional LSR and the proposed ANN method. METHODS: In vivo data of five healthy volunteers and one patient with a primary brain tumor were acquired at 3T using a gradient-echo sampled spin-echo (GESSE) sequence. The ANN was trained with simulated BOLD data. RESULTS: In healthy subjects, the mean OEF was 36 ± 2% (LSR) and 40 ± 1% (ANN). The OEF variance within subjects was reduced from 8% to 6% using the ANN method. In the patient, both methods revealed a distinct OEF hotspot in the tumor area, whereas ANN showed less apparent artifacts in surrounding tissue. CONCLUSION: In clinical scan times, the ANN analysis enables OEF mapping with reduced variance, which could facilitate its integration into clinical protocols. Magn Reson Med 79:890-899, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Imaging of Orthotopic Glioblastoma Xenografts in Mice Using a Clinical CT Scanner: Comparison with Micro-CT and Histology.

PURPOSE: There is an increasing need for small animal in vivo imaging in murine orthotopic glioma models. Because dedicated small animal scanners are not available ubiquitously, the applicability of a clinical CT scanner for visualization and measurement of intracerebrally growing glioma xenografts in living mice was validated. MATERIALS AND METHODS: 2.5x106 U87MG cells were orthotopically implanted in NOD/SCID/ᵞc-/- mice (n = 9). Mice underwent contrast-enhanced (300 µl Iomeprol i.v.) imaging using a micro-CT (80 kV, 75 µAs, 360° rotation, 1,000 projections, scan time 33 s, resolution 40 x 40 x 53 µm) and a clinical CT scanner (4-row multislice detector; 120 kV, 150 mAs, slice thickness 0.5 mm, feed rotation 0.5 mm, resolution 98 x 98 x 500 µm). Mice were sacrificed and the brain was worked up histologically. In all modalities tumor volume was measured by two independent readers. Contrast-to-noise ratio (CNR) and Signal-to-noise ratio (SNR) were measured from reconstructed CT-scans (0.5 mm slice thickness; n = 18). RESULTS: Tumor volumes (mean±SD mm3) were similar between both CT-modalities (micro-CT: 19.8±19.0, clinical CT: 19.8±18.8; Wilcoxon signed-rank test p = 0.813). Moreover, between reader analyses for each modality showed excellent agreement as demonstrated by correlation analysis (Spearman-Rho >0.9; p<0.01 for all correlations). Histologically measured tumor volumes (11.0±11.2) were significantly smaller due to shrinkage artifacts (p<0.05). CNR and SNR were 2.1±1.0 and 1.1±0.04 for micro-CT and 23.1±24.0 and 1.9±0.7 for the clinical CTscanner, respectively. CONCLUSION: Clinical CT scanners may reliably be used for in vivo imaging and volumetric analysis of brain tumor growth in mice.

Perfusion-weighted imaging and dynamic 4D angiograms for the estimation of collateral blood flow in lacunar infarction.

Although lacunar infarction accounts for approximately 25% of ischemic strokes, collateral blood flow through anastomoses is not well evaluated in lacunar infarction. In 111 lacunar infarction patients, we analyzed diffusion-weighted images, perfusion-weighted images, and blood flow on dynamic four-dimensional angiograms generated by use of Signal Processing In NMR-Software. Blood flow was classified as absent (type 1), from periphery to center (type 2), from center to periphery (type 3), and combination of type 2 and 3 (type 4). On diffusion-weighted images, lacunar infarction was found in the basal ganglia (11.7%), internal capsule (24.3%), corona radiata (30.6%), thalamus (24.3%), and brainstem (9.0%). In 58 (52.2%) patients, perfusion-weighted image showed a circumscribed hypoperfusion, in one (0.9%) a circumscribed hyperperfusion, whereas the remainder was normal. In 36 (62.1%) patients, a larger perfusion deficit (>7 mm) was observed. In these, blood flow was classified type 1 in four (11.1%), 2 in 17 (47.2%), 3 in 9 (25.0%), and 4 in six (16.7%) patients. Patients with lacunar infarction in the posterior circulation more often demonstrated blood flow type 2 and less often type 3 (p = 0.01). Detailed examination and graduation of blood flow in lacunar infarction by use of dynamic four-dimensional angiograms is feasible and may serve for a better characterization of this stroke subtype.

Sparing of the hippocampus indicates better collateral blood flow in acute posterior cerebral artery occlusion.

BACKGROUND: In acute posterior cerebral artery, occlusion involvement of the hippocampus is a common finding. Nevertheless, until today, infarction and ischemic lesion evolution in the hippocampus has not been studied systematically. AIM: Evaluation of hippocampal infarction patterns in posterior cerebral artery occlusion in the very early phase (≤six-hours) and ischemic lesion evolution on follow-up magnetic resonance imaging in relation to collateral blood flow assessed by a magnetic resonance imaging-based approach was conducted. METHODS: In 28 patients [mean age 69·4 ± 13·8 years, 19 (67·9%) males, 10 (32·1%) females] with proximal posterior cerebral artery occlusion, magnetic resonance imaging findings were analyzed, with emphasis on hippocampal infarction patterns on diffusion-weighted images and collateralization on dynamic 4D angiograms derived from perfusion-weighted raw images. RESULTS: On initial diffusion-weighted images, we identified all known hippocampal infarction patterns: type 1 (complete) in 6/18 (33·3%) patients, type 2 (lateral) in 10/18 (55·6%) patients, and type 3 (dorsal) and type 4 (circumscribed) in 1/18 (5·6%) patient respectively. On dynamic 4D angiograms, the grade of collateralization was classified as 1 in 9 (32·1%), 2 in 1 (3·6%), 3 in 10 (35·7%), and 4 in 8 (28·6%) patients. On follow-up diffusion-weighted images, we found new ischemic lesions in three and infarction growth in the hippocampus in five patients. Patients with better collateralization (grades 3 and 4) less often had hippocampal infarctions on initial (P = 0·003)/follow-up diffusion-weighted images (P = 0·046) as well as type 1 on initial (P = 0·007)/follow-up diffusion-weighted images (P = 0·005). CONCLUSIONS: Involvement of the hippocampus in proximal posterior cerebral artery occlusion is frequently but not obligatorily observed and highly dependent on the extent of collateralization. The same holds true for hippocampal infarction patterns.

Value of dynamic susceptibility contrast perfusion MRI in the acute phase of transient global amnesia.

PURPOSE: Transient global amnesia (TGA) is a transitory, short-lasting neurological disorder characterized by a sudden onset of antero- and retrograde amnesia. Perfusion abnormalities in TGA have been evaluated mainly by use of positron emission tomography (PET) or single-photon emission computed tomography (SPECT). In the present study we explore the value of dynamic susceptibility contrast perfusion-weighted MRI (PWI) in TGA in the acute phase. METHODS: From a MRI report database we identified TGA patients who underwent MRI including PWI in the acute phase and compared these to control subjects. Quantitative perfusion maps (cerebral blood flow (CBF) and volume (CBV)) were generated and analyzed by use of Signal Processing In NMR-Software (SPIN). CBF and CBV values in subcortical brain regions were assessed by use of VOI created in FIRST, a model-based segmentation tool in the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB) Software Library (FSL). RESULTS: Five TGA patients were included (2 men, 3 women). On PWI, no relevant perfusion alterations were found by visual inspection in TGA patients. Group comparisons for possible differences between TGA patients and control subjects showed significant lower rCBF values bilaterally in the hippocampus, in the left thalamus and globus pallidus as well as bilaterally in the putamen and the left caudate nucleus. Correspondingly, significant lower rCBV values were observed bilaterally in the hippocampus and the putamen as well as in the left caudate nucleus. Group comparisons for possible side differences in rCBF and rCBV values in TGA patients revealed a significant lower rCBV value in the left caudate nucleus. CONCLUSIONS: Mere visual inspection of PWI is not sufficient for the assessment of perfusion changes in TGA in the acute phase. Group comparisons with healthy control subjects might be useful to detect subtle perfusion changes on PWI in TGA patients. However, this should be confirmed in larger data sets and serial PWI examinations.

Fluid Attenuated Inversion Recovery Vascular Hyperintensities Possibly Indicate Slow Arterial Blood Flow in Vertebrobasilar Dolichoectasia.

BACKGROUND AND PURPOSE: Vertebrobasilar dolichoectasia (VBD) is a dilatative arteriopathy associated with a decreased blood flow velocity. Fluid attenuated inversion recovery (FLAIR) vascular hyperintensity (FVH) is a phenomenon most likely representing slow arterial blood flow. We sought to examine the frequency and extent of FVH in VBD. METHODS: We analyzed magnetic resonance imaging (MRI) findings in 77 VBD patients with special emphasis on FVH in relation to the diagnostic MRI criteria of VBD and the etiology in symptomatic patients. RESULTS: In 49 (63.6%) VBD patients, FVH could be detected: in 22 (44.9%) a small hyperintense rim near the vessel wall (grade 1), in 20 (40.8%) a strong hyperintense rim near the vessel wall (grade 2), and in 7 (14.3%) the hyperintense signal filled the complete vessel lumen (grade 3). The diameter of the basilar artery moderately correlated with the extent of FVH. A higher FVH grade (2 and 3) was more common in patients with TIA/stroke related to VBD (9/16 [56.3%]) in comparison to patients with other etiology and asymptomatic patients (18/61 [29.5%]; P = .046). CONCLUSIONS: FVH may be useful to demonstrate the decreased blood flow velocity in VBD. More pronounced FVH in patients with posterior circulation TIA/stroke might reflect the underlying stroke pathomechanism.

Early blood-based microbiological testing is ineffective in severe stroke patients.

BACKGROUND AND PURPOSE: Patients with severe acute stroke are at high risk for systemic infections which are associated with an increase in morbidity and mortality; nevertheless current guidelines do not recommend prophylactic antibiotic therapy. Sensitive detection of pathogens in the blood is desirable to guide early antibiotic therapy. We studied the yield of blood culture testing and microbiological PCR-based methods for early detection of post-stroke bacteremia. METHODS: Serial blood culture tests either during the first fever episode (>38.5°C) or 24h after admission were performed every 12h for up to 96h after admission. Additionally, microbiological PCR-based techniques for the detection of microbiological pathogens were performed once during the first fever episode prior to initiating antibiotic treatment. RESULTS: 21 severely affected acute stroke patients deemed at high risk for systemic infections (median (interquartile range (IQR)) at admission NIHSSS 19 (15-30) were enrolled; 20 patients were intubated within 5h after ICU admission. All patients developed clinical signs and laboratory constellations compatible with systemic infections within 36h after admission. However, no patient had pathogenic bacteria either in serial blood culture analyses during the first 96h after admission or by PCR-based techniques. CONCLUSIONS: Very early bacteremia seems not to be a feature of severe stroke in patients despite signs of early immune system depression and frequent subsequent evidence of infection including pneumonia. Consequently our data suggests, that routine early blood-based standard or molecular microbiological assays do not reveal bacteremia, this finding questions the usefulness of their routine performance in this context.

Usefulness of serum procalcitonin levels for the early diagnosis of stroke-associated respiratory tract infections.

BACKGROUND: Patients with extensive brain infarcts are at increased risk for stroke-associated respiratory tract infections (SARTI), which cause worse outcome. The benefit of general antibiotic prophylaxis is controversial. Early diagnosis of SARTI may improve patient selection for antimicrobial therapy. Procalcitonin (PCT) is widely recognized as serum marker for bacterial infections. Its diagnostic value with respect to SARTI has not been assessed systematically. METHODS: Serum PCT levels were analyzed in ischemic stroke patients (n = 50) at day 1 (d1) and day 4 (d4) after stroke onset. PCT test performance was assessed by receiver operator characteristics (ROC) curve analysis. Multivariable logistic regression analysis was applied to identify early predictors for SARTI. RESULTS: Higher d4 serum PCT levels were associated with SARTI; ROC curve analysis revealed an area under the curve (AUC) of 0.79 (95%-confidence interval (CI) 0.61-0.96). A 0.25-ng/ml cutoff resulted in a test sensitivity and specificity of 42 and 96%, respectively. Positive (LR+) and negative (LR-) likelihood ratios were 10.8 and 0.6, respectively. In predicting SARTI, multivariable logistic regression analysis controlling for infarct volume ruled out an independent explanatory effect of serum PCT. Greater infarct volume (odds ratio (OR) 1.06, 95%-CI 1.02-1.1) prevailed as independent SARTI-predictor. CONCLUSIONS: In the absence of clinical signs, post-stroke screening for SARTI using serum PCT levels is not useful since test sensitivity is low. If the clinical suspicion for SARTI is strong, serum PCT-testing (>0.25 ng/ml) may improve diagnostic accuracy by improving specificity.

Cl- interference with the epithelial Na+ channel ENaC.

The cystic fibrosis transmembrane conductance regulator (CFTR) is a protein kinase A and ATP-regulated Cl- channel that also controls the activity of other membrane transport proteins, such as the epithelial Na+ channel ENaC. Previous studies demonstrated that cytosolic domains of ENaC are critical for down-regulation of ENaC by CFTR, whereas others suggested a role of cytosolic Cl- ions. We therefore examined in detail the anion dependence of ENaC and the role of its cytosolic domains for the inhibition by CFTR and the Cl- channel CLC-0. Coexpression of rat ENaC with human CFTR or the human Cl- channel CLC-0 caused inhibition of amiloride-sensitive Na+ currents after cAMP-dependent stimulation and in the presence of a 100 mM bath Cl- concentration. After activation of CFTR by 3-isobutyl-1-methylxanthine and forskolin or expression of CLC-0, the intracellular Cl- concentration was increased in Xenopus oocytes in the presence of a high bath Cl- concentration, which inhibited ENaC without changing surface expression of alpha beta gammaENaC. In contrast, a 5 mM bath Cl- concentration reduced the cytosolic Cl- concentration and enhanced ENaC activity. ENaC was also inhibited by injection of Cl- into oocytes and in inside/out macropatches by exposure to high cytosolic Cl- concentrations. The effect of Cl- was mimicked by Br-, Br-, NO3(-), and I-. Inhibition by Cl- was reduced in trimeric channels with a truncated COOH terminus of betaENaC and gammaENaC, and it was no longer detected in dimeric alpha deltaCbeta ENaC channels. Deletion of the NH2 terminus of alpha-, beta-, or gammaENaC, mutations in the NH2-terminal phosphatidylinositol bisphosphate-binding domain of betaENaC and gammaEnaC, and activation of phospholipase C, all reduced ENaC activity but allowed for Cl(-)-dependent inhibition of the remaining ENaC current. The results confirm a role of the carboxyl terminus of betaENaC for Cl(-)-dependent inhibition of the Na+ channel, which, however, may only be part of a complex regulation of ENaC by CFTR.

Control of ion transport in mammalian airways by protease activated receptors type 2 (PAR-2).

Protease-activated receptors (PARs) are widely distributed in human airways. They couple to G- proteins and are activated after proteolytic cleavage of the N terminus of the receptor. Evidence is growing that PAR subtype 2 plays a pivotal role in inflammatory airway diseases, such as allergic asthma or bronchitis. However, nothing is known about the effects of PAR-2 on electrolyte transport in the native airways. PAR-2 is expressed in airway epithelial cells, where they are activated by mast cell tryptase, neutrophil proteinase 3, or trypsin. Recent studies produced conflicting results about the functional consequence of PAR-2 stimulation. Here we report that stimulation of PAR-2 receptors in mouse and human airways leads to a change in electrolyte transport and a shift from absorption to secretion. Although PAR-2 appears to be expressed on both sides of the epithelium, only basolateral stimulation results in inhibition of amiloride sensitive Na+ conductance and stimulation of both luminal Cl- channels and basolateral K+ channels. The present data indicate that these changes occur through activation of phospholipase C and increase in intracellular Ca2+, which activates basolateral SK4 K+ channels and luminal Ca2+-dependent Cl- channels. In addition, the present data suggest a PAR-2 mediated release of prostaglandin E2, which may contribute to the secretory response. In conclusion, these results provide further evidence for a role of PAR-2 in inflammatory airway disease: stimulation of these receptors may cause accumulation of airway surface liquid, which, however, may help to flush noxious stimuli away from the affected airways.