18F-Fluoro-Ethyl-Tyrosine (FET) Positron Emission Tomography (PET) and Grading Glioma

Study Overview
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Brief Summary
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Role of 18F-FET PET for grading gliomas according to 2016 WHO classification: value of quantitative and qualitative data obtained by 18F-FET PET for differentiating low grade glioma (WHO II) versus high grade gliomas (WHO III and IV)

Detailed Description
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The management and prognosis of patients with glioma is highly dependent on the tumour grade according to the new 2016 classification of the World Health Organization (WHO), which incorporates molecular characteristics. Standard magnetic resonance imaging (MRI) enhanced by contrast is the basis of imaging primary brain tumours including gliomas. Nevertheless MRI specificity to type glioma is limited. Recently, positron emission tomography (PET) molecular imaging using radiolabeled amino acids or their analogues has been recommended by the Neuro-Oncology Response Assessment (RANO) working group for differential diagnosis of brain lesions, non-invasive classification of glial tumours, prognostic value, tumour delineation, stereotactic biopsy radiotherapy planification and treatments follow-up, to provide additional informations beyond MRI on biological processes such as cell proliferation, membrane biosynthesis, glucose consumption and absorption of amino acid analogues. Among the radiotracers used in PET, radiolabeled amino acids or their analogues are increasingly used in clinical routine for glioma imaging. Although most previous PET studies focused on brain gliomas used L-[methyl- 11 C] -methionine (11C-MET), the fluorinated amino acid analogue O - (2-[ 18 F] fluoroethyl) -L-tyrosine (18F-FET) appeared to be a favorable marker for clinical routine due to his longer half-life than Carbone 11. Recent european guidelines attempt to provide some guidance on the performance and interpretation of molecular imaging. The authors recommend a static (20-40 mn after injection (Pi)) or dynamic PET acquisition (40-50 mn from injection). A visual analysis can be completed by a quantitative analysis which consists to measure mean and maximal tumour activity uptake values (SUVmean and SUVmax) and their respective tumour to background ratios (TBRmean and TBRmax). Although the mean physiological brain activity uptake is well defined, the measurement of mean glioma activity uptake is less clear. Indeed, TBRmean depends on the delineation of the tumour ROI and/or VOI. Most often previously, VOI was determined by a 3D contouring process using a tumour-to-brain ratio of at least 1.6 at the beginning of the scan, threshold defined on a brain gliomas biopsy-controlled study. Moreover, Albert et al. emphasized the interest of early TBRmax.To our knowledge, none study evaluated others parameters as SUVmax, SUVmean and TBRmean in early period. In this context, the aim of this study was to compare quantitative and qualitative PET parameters between Low Grade Glioma and High Grade Glioma.

Official Title
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Role of 18F-Fluoro-Ethyl-Tyrosine (FET) Positron Emission Tomography (PET) for Grading Glioma

Conditions
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Positron Emission Tomography, Glioma

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: glial tumor patient underwent 18F-FET PET at Brest University Hospital no opposite to participate Exclusion Criteria: patient Under 18 years old opposite to participate

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| quantitative criteria (SUVmax) between 2 groups (glioma II vs glioma III-IV) | study mean value of SUVmax obtained by 18F-FET PET between 2 groups (glioma II vs glioma III-IV) | 3 months | 
| quantitative criteria (TBRmax) between 2 groups (glioma II vs glioma III-IV) | study mean value of TBRmax obtained by 18F-FET PET between 2 groups (glioma II vs glioma III-IV) | 3 months | 
| quantitative criteria (SUVmean) between 2 groups (glioma II vs glioma III-IV) | study mean value of SUVmean obtained by 18F-FET PET between 2 groups (glioma II vs glioma III-IV) | 3 months | 
| quantitative criteria (TBRmean) between 2 groups (glioma II vs glioma III-IV) | study mean value of TBRmean obtained by 18F-FET PET between 2 groups (glioma II vs glioma III-IV) | 3 months | 
| quantitative criteria (SUVpeak) between 2 groups (glioma II vs glioma III-IV) | study mean value of SUVpeak obtained by 18F-FET PET between 2 groups (glioma II vs glioma III-IV) | 3 months | 
| quantitative criteria (métabolic tumoral volume MTV) between 2 groups (glioma II vs glioma III-IV) | study mean value of MTV obtained by 18F-FET PET between 2 groups (glioma II vs glioma III-IV) | 3 months | 
| quantitative criteria (Total Lesion Glycolysis TLG) between 2 groups (glioma II vs glioma III-IV) | study mean value of TLG obtained by 18F-FET PET between 2 groups (glioma II vs glioma III-IV) | 3 months | 
| quantitative criteria (SUVmin) between 2 groups (glioma II vs glioma III-IV) | study mean value of SUVmin obtained by 18F-FET PET between 2 groups (glioma II vs glioma III-IV) | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| qualitative criteria (Time Activity Curve TAC) between 2 groups (glioma II vs glioma III-IV) | study qualitative data obtained by 18F-FET PET between 2 groups (glioma II vs glioma III-IV) | 3 months | 
| agreement between readers for quantitative and qualitative criteria | study inter and intra observers agreement | 3 months | 
| diagnostic accuracy of clinical data to discriminate the 2 groups of glioma (symptom or size of tumor) | study diagnostic accuracy of clinical data | 3 months | 
| diagnostic accuracy of biological criteria (as MGMT mutation or IDH status or 1p19q codeletion, ATRX status) to discriminate the 2 groups of glioma | study diagnostic accuracy of biological data | 3 months | 
| diagnostic accuracy of PET criteria (SUVmax, TBRmax, SUVmean, TBRmean, SUVpeak, SUVmin, TLG and MTV) between the 2 groups of glioma | study diagnostic accuracy of PET data | 3 months | 
| prognostic value of F-FET PET data on PET Baseline on PFS | study the prognostic value of PET criteria on PFS | 2 years and 3 months | 
| prognostic value of F-FET PET data on PET Baseline on OS | study the prognostic value of PET criteria on OS | 2 years and 3 months | 
| prognostic value of variation of quantitative PET data (SUVmax, TBRmax, SUVmean, TBRmean, SUVpeak, SUVmin, MTV, TLG) (for example deltaSUVmax between PET Baseline and PET 3 months) on PFS | modification of PET criteria between PET Baseline and PET at follow-up and their prognostic value on PFS | 2 years and 3 months | 
| prognostic value of variation of quantitative PET data (SUVmax, TBRmax, SUVmean, TBRmean, SUVpeak, SUVmin, MTV, TLG) (for example deltaSUVmax between PET Baseline and PET 3 months) on OS | modification of PET criteria between PET Baseline and PET at follow-up and their prognostic value on OS | 2 years and 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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18F-FET PET, glioma, grading