title: Respiratory gated PET/CT in a European multicentre retrospective study: added diagnostic value in detection and characterization of lung lesions.
abstract: OBJECTIVE
  The aim of our work is to evaluate the added diagnostic value of respiratory gated (4-D) positron emission tomography/computed tomography (PET/CT) in lung lesion detection/characterization in a large patient population of a multicentre retrospective study.
  
  
  METHODS
  The data of 155 patients (89 men, 66 women, mean age 63.9 ± 11.1 years) from 5 European centres and submitted to standard (3-D) and 4-D PET/CT were retrospectively analysed. Overall, 206 lung lesions were considered for the analysis (mean ± SD lesions dimension 14.7 ± 11.8 mm). Maximum standardized uptake values (SUV(max)) and lesion detectability were assessed for both 3-D and 4-D PET/CT studies; 3-D and 4-D PET/CT findings were compared to clinical follow-up as standard reference.
  
  
  RESULTS
  Mean ± SD 3-D and 4-D SUV(max) values were 5.2 ± 5.1 and 6.8 ± 6.1 (p < 0.0001), respectively, with an average percentage increase of 30.8 %. In 3-D PET/CT, 86 of 206 (41.7 %) lesions were considered positive, 70 of 206 (34 %) negative and 50 of 206 (24.3 %) equivocal, while in 4-D PET/CT 117 of 206 (56.8 %) lesions were defined as positive, 80 of 206 (38.8 %) negative and 9 of 206 (4.4 %) equivocal. In 34 of 50 (68 %) 3-D equivocal lesions follow-up data were available and the presence of malignancy was confirmed in 21 of 34 (61.8 %) lesions, while in 13 of 34 (38.2 %) was excluded. In 31 of these 34 controlled lesions, 20 of 34 (58.8 %) and 11 of 34 (32.4 %) were correctly classified by 4-D PET/CT as positive and negative, respectively; 3 of 34 (8.8 %) remained equivocal. With equivocal lesions classified as positive, the overall accuracy of 3-D and 4-D was 85.7 and 92.8 %, respectively, while the same figures were 80.5 and 94.2 % when equivocal lesions were classified as negative.
  
  
  CONCLUSIONS
  The respiratory gated PET/CT technique is a valuable clinical tool in diagnosing lung lesions, improving quantification and confidence in reporting, reducing 3-D undetermined findings and increasing the overall accuracy in lung lesion detection and characterization.
authors.affiliation: Nuclear Medicine, San Gerardo Hospital, Via Pergolesi 33, 20900 Monza, Italy. l.guerra@hsgerardo.org
authors.forename: Luca
authors.initials: L
authors.lastname: Guerra
authors.forename: Elena
authors.initials: E
authors.lastname: De Ponti
authors.forename: Federica
authors.initials: F
authors.lastname: Elisei
authors.forename: Valentino
authors.initials: V
authors.lastname: Bettinardi
authors.forename: Claudio
authors.initials: C
authors.lastname: Landoni
authors.forename: Maria
authors.initials: M
authors.lastname: Picchio
authors.forename: Maria Carla
authors.initials: MC
authors.lastname: Gilardi
authors.forename: Annibale
authors.initials: A
authors.lastname: Versari
authors.forename: Federica
authors.initials: F
authors.lastname: Fioroni
authors.forename: Miroslaw
authors.initials: M
authors.lastname: Dziuk
authors.forename: Magdalena
authors.initials: M
authors.lastname: Koza
authors.forename: Renée
authors.initials: R
authors.lastname: Ahond-Vionnet
authors.forename: Bertrand
authors.initials: B
authors.lastname: Collin
authors.forename: Cristina
authors.initials: C
authors.lastname: Messa
mesh_terms: D005060:Europe; D005260:Female; D056973:Four-Dimensional Computed Tomography; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D055425:Respiratory-Gated Imaging Techniques; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed