Caroline Bund

FDOPA PET-CT of Nonenhancing Brain Tumors.

Background Primary brain tumor grading is crucial to rapidly determine the therapeutic impact and prognosis of a brain tumor as well as the tumors’ aggressiveness profile. On magnetic resonance imaging, high-grade tumors are usually responsible for blood -brain barrier breakdowns, which result in tumor enhancement. However, this is not always the case. The main objective of this study was to evaluate the diagnostic value of FDOPA PET in the assessment of primary brain tumor aggressiveness with no contrast enhancement on MRI. Methods Fifty-three patients were prospectively included: 35 low-grade and 18 high-grade histologically proven gliomas, with no contrast enhancement. Each patient underwent static PET acquisitions at 30 minutes. All patients had MRSI with measurements of different metabolites ratio. Results FDOPA was useful in the subgroup of low-grade gliomas, discriminating between dysembryoplastic neuroepithelial tumor and grade II oligodendroglioma (P < 0.01). An optimal threshold of the maximum standardized uptake value at 30 minutes (SUVmax (T/N)30) = 2.16 to discriminated low- from high-grade gliomas with a sensitivity of 60%, specificity of 100%, PPV of 100%, and NPV of 83.33% (P < 0.01). The nCho/Cr and nCho/NAA ratios were significantly higher in high- than in low-grade gliomas (P < 0.03 and P < 0.04, respectively). A significant positive correlation between MRSI ratios and SUVmax was found. Conclusion Including data from amino acid metabolism used alone or in association with MRSI allows us to discriminate between dysembryoplastic neuroepithelial tumor and grade II oligodendroglioma and between low- and high-grade gliomas with no contrast enhancement on MRI.

Metabolomics approaches in experimental allergic encephalomyelitis

A myelin basic protein (MBP)-induced experimental allergic encephalomyelitis (EAE) involves paraplegia due to a reversible thoracolumbar spinal cord impairment. The aims of this study were thus to find significant metabolic biomarkers of inflammation and identify the site of inflammation in the central nervous system (CNS) during the acute signs in of the disease using metabolomics. All the EAE samples were associated with higher levels of lactate, ascorbate, glucose and amino acids, and decreased level of N-acetyl-aspartate (NAA) compared to the control group. A decreased NAA level has been particularly shown in lumbar spinal cord in relationship with the clinical signs.

Positional Brain Single-Photon Emission Computed Tomography Findings in a Case of Limb-Shaking Syndrome

An 84-year-old man, who presented lower limbs limb-shaking syndrome at orthostatism lasting a few seconds, was referred in our stroke unit. Magnetic resonance imaging showed an acute infarction in the right thalamus and the insular cortex, left extracranial carotid stenosis at 80%, and low flow in the right middle cerebral artery but did not explain limb-shaking syndrome symptomatology. We performed comparative positional brain perfusion single-photon emission computed tomography (SPECT), in the upright and in the supine position, to explore and localize hypoperfusion-endangered brain structures that may be involved in the presenting symptoms. Brain perfusion SPECT showed deep hypoperfusion in bilateral carotid territories in the upright position in favor of a hemodynamic mechanism, on which blood pressure was maintained higher to avoid hypoperfusion and the patient remained supine for a longer period of time than in the usual support. Late postoperative brain perfusion SPECT after left endarterectomy did not show significant abnormalities. Limb-shaking syndrome may be related to a transient decrease in blood pressure and cerebral blood flow caused by postural changes. Positional brain perfusion SPECT seems to be helpful to improve clinical care. Positional brain perfusion SPECT should be discussed in the acute phase of stroke and if there are involuntary movements.

Predictive Value of 1 Month Postoperative MRSI and FDG-PETEvaluations of Glioblastomas

Aim: The purpose of this study was to investigate prospectively the predictive value of positron emission tomography with proton magnetic resonance spectroscopic imaging (MRSI) and 18F-fluorodeoxyglucose (FDG-PET) performed the 1st month after surgery and before radio- chemotherapy in 43 patients with glioblastoma (GBM). Patients and methods: Metabolite concentrations were quantified using LCModel. Overall survival (OS) and progression free survival (PFS) were calculated including all 43 patients using Kaplan-Meier curves, and the Cox proportional hazard model was used to calculate the predictor of survival. Results: At the end of the follow-up period, all patients died within a period of 1–70.2 months. In 32 patients (74.4%), increased FDG-uptake was seen around the resection cavity and abnormal metabolic profiles on MRSI, indicative of residual disease, were present in all patients. There was no significant difference between the median OS in patients with hypometabolic FDG lesions compared to patients with hypermetabolic FDG lesions. On univariate analysis, normalized choline-containing compounds/creatine (nCho/Cr) and normalized lactate/creatine (nLac/Cr) were significantly predictive of OS and nLac/Cr and normalized N-Acetylaspartylglutamate and NAcetylaspartate/ creatine (NAA/Cr) were significantly predictive of PFS. Conclusions: nCho/Cr and nLac/Cr ratio after surgery and before radio-chemotherapy were independent metabolic predictive factors of OS times in newly diagnosed patients with GBM.

FDG PET in Intracranial Carcinomatous Meningitis.

A 63-year-old white man, diagnosed with pT3N2 squamous cell lung carcinoma, underwent right upper lobectomy with adjuvant radiochemotherapy. After a partial epileptic seizure, MRI revealed a solitary right frontal metastasis that was treated with surgical resection followed by stereotaxic radiotherapy. Three months later, the patient presented weight loss, weakness, and headache. He underwent a whole-body FDG PET/CT for restaging. It showed intense FDG uptakes on the brain periphery corresponding to nodular meningeal contrast enhancement on MRI leading to the diagnosis of carcinomatous meningitis, despite negative cerebrospinal fluid cytology.

Metabolomic characterization of human hippocampus from drug-resistant epilepsy with mesial temporal seizure

Within a complex systems biology perspective, we wished to assess whether hippocampi with established neuropathological features have distinct metabolome. Apparently normal hippocampi with no signs of sclerosis (noHS), were compared to hippocampal sclerosis (HS) type 1 (HS1) and/or type 2 (HS2). Hippocampus metabolome from patients with epilepsy‐associated neuroepithelial tumors (EANTs), namely, gangliogliomas (GGs) and dysembryoplastic neuroepithelial tumors (DNTs), was also compared to noHS epileptiform tissue.

Sequential FDG PET and MRI findings in a case of SMART syndrome

a Service de Biophysique et Médecine Nucléaire, Hôpitaux Universitaires de Strasbourg, France b ICube, Université de Strasbourg/CNRS (UMR 7357), Strasbourg, France c Fédération de Médecine Translationnelle de Strasbourg (FMTS), Faculté de Médecine, Strasbourg, France d Service de Neurologie, Hôpitaux Universitaires de Strasbourg, France e Service de Radiologie, Hôpitaux Universitaires de Strasbourg, France