Frontiers in Neurology (Apr 2019)

Epileptogenic Zone Localization With 18FDG PET Using a New Dynamic Parametric Analysis

  • Maria Mayoral,
  • Aida Niñerola-Baizán,
  • Aida Niñerola-Baizán,
  • Berta Marti-Fuster,
  • Berta Marti-Fuster,
  • Antonio Donaire,
  • Antonio Donaire,
  • Andrés Perissinotti,
  • Jordi Rumià,
  • Núria Bargalló,
  • Núria Bargalló,
  • Roser Sala-Llonch,
  • Javier Pavia,
  • Javier Pavia,
  • Javier Pavia,
  • Domènec Ros,
  • Domènec Ros,
  • Domènec Ros,
  • Mar Carreño,
  • Mar Carreño,
  • Francesca Pons,
  • Francesca Pons,
  • Xavier Setoain,
  • Xavier Setoain,
  • Xavier Setoain

DOI
https://doi.org/10.3389/fneur.2019.00380
Journal volume & issue
Vol. 10

Abstract

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Introduction: [18F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) is part of the regular preoperative work-up in medically refractory epilepsy. As a complement to visual evaluation of PET, statistical parametric maps can help in the detection of the epileptogenic zone (EZ). However, software packages currently available are time-consuming and little intuitive for physicians. We develop a user-friendly software (referred as PET-analysis) for EZ localization in PET studies that allows dynamic real-time statistical parametric analysis. To evaluate its performance, the outcome of PET-analysis was compared with the results obtained by visual assessment and Statistical Parametric Mapping (SPM).Methods: Thirty patients with medically refractory epilepsy who underwent presurgical 18F-FDG PET with good post-operative outcomes were included. The 18F-FDG PET studies were evaluated by visual assessment, with SPM8 and PET-analysis. In SPM, parametric T-maps were thresholded at corrected p < 0.05 and cluster size k = 50 and at uncorrected p < 0.001 and k = 100 (the most used parameters in the literature). Since PET-analysis rapidly processes different threshold combinations, T-maps were thresholded with multiple p-value and different clusters sizes. The presurgical EZ identified by visual assessment, SPM and PET-analysis was compared to the confirmed EZ according to post-surgical follow-up.Results: PET-analysis obtained 66.7% (20/30) of correctly localizing studies, comparable to the 70.0% (21/30) achieved by visual assessment and significantly higher (p < 0.05) than that obtained with the SPM threshold p < 0.001/k = 100, of 36.7% (11/30). Only one study was positive, albeit non-localizing, with the SPM threshold corrected p < 0.05/k = 50. Concordance was substantial for PET-analysis (κ = 0.643) and visual interpretation (κ = 0.622), being fair for SPM (κ = 0.242).Conclusion: Compared to SPM with the fixed standard parameters, PET-analysis may be superior in EZ localization with its easy and rapid processing of different threshold combinations. The results of this initial proof-of-concept study validate the clinical use of PET-analysis as a robust objective complementary tool to visual assessment for EZ localization.

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