title: Investigation on the role of integrated PET/MRI for target volume definition and radiotherapy planning in patients with high grade glioma.
abstract: OBJECTIVE
  To evaluate the impact of fluid-attenuated-inversion-recovery MRI (FLAIR/MRI) and Carbon-11-labeled-methionine PET (11C-MET-PET) on high grade glioma (HGG) tumor volume delineation for radiotherapy planning.
  
  
  METHODS
  Sixty-nine patients with HGG were evaluated. The clinical target volumes (CTV1, generated by adding a 10mm margin to FLAIRMRI area, CTV2 by adding a 20mm margin to enhanced T1MRI) and biological target volume (BTV) were delineated on pre-operative MRI images and 11CMETPET respectively.
  
  
  RESULTS
  The overlap between CTV1 and CTV2 showed a low correlation between the two volumes with CTV1 not always fully included into the CTV2. In all cases the whole BTV was included into the CTV1, while in 35/69 patients (50%) part of BTV was outside the CTV2 despite larger margins were added. In all cases recurrences were within the CTV1 volume and in 19/38 (50%) partially outside the CTV2. In all patients relapse corresponded to the BTV area.
  
  
  CONCLUSIONS
  Our data suggest that the target volume definition using FLAIR-MRI is more adequate compared to enhanced T1MRI. 11C-METPET uptake could help identify microscopic residual areas.
authors.affiliation: Radiotherapy and Radiosurgery Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy. Electronic address: piera.navarria@cancercenter.humanitas.it.
authors.forename: Pierina
authors.initials: P
authors.lastname: Navarria
authors.affiliation: Radiotherapy and Radiosurgery Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Reggiori
authors.affiliation: Neurosurgical Oncology Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Pessina
authors.affiliation: Radiotherapy and Radiosurgery Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Ascolese
authors.affiliation: Radiotherapy and Radiosurgery Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Tomatis
authors.affiliation: Radiotherapy and Radiosurgery Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Mancosu
authors.affiliation: Radiotherapy and Radiosurgery Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Lobefalo
authors.affiliation: Radiotherapy and Radiosurgery Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Clerici
authors.affiliation: Nuclear Medicine Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Egesta
authors.initials: E
authors.lastname: Lopci
authors.affiliation: Neuroradiology Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Bizzi
authors.affiliation: Neuroradiology Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Grimaldi
authors.affiliation: Nuclear Medicine Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Arturo
authors.initials: A
authors.lastname: Chiti
authors.affiliation: Oncology and Hematology Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Simonelli
authors.affiliation: Oncology and Hematology Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Armando
authors.initials: A
authors.lastname: Santoro
authors.affiliation: Neurosurgical Oncology Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bello
authors.affiliation: Radiotherapy and Radiosurgery Department, Istituto Clinico Humanitas Cancer Center, Milan, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Scorsetti
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D002250:Carbon Radioisotopes; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008715:Methionine; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D011859:Radiography; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D047368:Tumor Burden
chemical_list: D002250:Carbon Radioisotopes; D008715:Methionine
keywords: High grade glioma; MET-PET; Radiotherapy-planning