title: Multiparametric evaluation of low grade gliomas at follow-up: comparison between diffusion and perfusion MR with (18)F-FDOPA PET.
abstract: OBJECTIVE
  To compare MRI using perfusion and diffusion techniques with 6-[(18)F]-fluoro-L-3,4-dihydroxyphenylalanine ((18)F-FDOPA) positron emission tomography (PET) in the follow-up of low-grade gliomas (LGGs) and to identify the best imaging parameter to differentiate patients with different prognosis.
  
  
  METHODS
  Between 2010 and 2015, 12 patients with a pathology-proven diagnosis of LGG and MR (with perfusion and diffusion sequences) and a PET study during their follow-up were retrospectively included in our study. Cerebral blood volume (CBV) and apparent diffusion coefficient (ADC) maps on MR studies and PET images were evaluated using a region of interest-based method. All patients were categorized as stable or as having progressive disease at 1-year follow-up. Statistical analysis was performed using Pearson's correlation test and multivariate analysis of variance (p < 0.05).
  
  
  RESULTS
  No significant correlations were found between PET parameters [maximum tumour-to-controlateral normal brain ratio (T/Nmax) and tumour-to-striatum ratio] and ADC or relative CBV values measured in both PET hotspot regions and areas of maximum signal alterations. T/Nmax demonstrated a good sensitivity (83%) and specificity (100%) for differentiating two subgroups of patients with different outcomes at 1-year-follow-up (p < 0.05).
  
  
  CONCLUSIONS
  Perfusion and diffusion MR images provide different information compared with (18)F-FDOPA PET in LGGs during follow-up and therefore, they should be considered as complementary tools in the evaluation of these tumours. (18)F-FDOPA PET showed a significant prognostic role in the follow-up of LGGs and appeared to be a better tool than MR advanced techniques for outcome prediction. These results need to be confirmed with longitudinal studies on a larger population.
  
  
  CONCLUSIONS
  This is the first study that compared (18)F-FDOPA PET with perfusion and diffusion MR in LGGs during follow-up. These preliminary results highlight the importance of a multimodality approach in this field and evidence a potential role for (18)F-FDOPA PET to predict patients at risk for tumour progression.
authors: 1 NESMOS Department, Sant'Andrea Hospital, Sapienza University of Rome, Rome, Italy.|2 Neuroradiology Unit, Imaging Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
authors: Maria C
authors: http://orcid.org/0000-0002-2991-5840
authors: MC
authors: Rossi Espagnet
authors: 1 NESMOS Department, Sant'Andrea Hospital, Sapienza University of Rome, Rome, Italy.
authors: Andrea
authors: A
authors: Romano
authors: 1 NESMOS Department, Sant'Andrea Hospital, Sapienza University of Rome, Rome, Italy.
authors: Valeria
authors: V
authors: Mancuso
authors: 3 Unit of Nuclear Medicine, Department of Surgical and Medical Sciences and Translational Medicine, Sapienza University of Rome, Rome, Italy.
authors: Francesco
authors: F
authors: Cicone
authors: 4 Enterprise Risk Management, Medical Physics Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
authors: Antonio
authors: A
authors: Napolitano
authors: 5 Unit of Radiation Oncology, Department of Surgical and Medical Sciences and Translational Medicine, Sapienza University of Rome, Rome, Italy.
authors: Claudia
authors: C
authors: Scaringi
authors: 5 Unit of Radiation Oncology, Department of Surgical and Medical Sciences and Translational Medicine, Sapienza University of Rome, Rome, Italy.
authors: Giuseppe
authors: G
authors: Minniti
authors: 1 NESMOS Department, Sant'Andrea Hospital, Sapienza University of Rome, Rome, Italy.
authors: Alessandro
authors: A
authors: Bozzao
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals; C043437:fluorodopa F 18; D004295:Dihydroxyphenylalanine