title: [Validation of segmentation techniques for positron emission tomography using ex-vivo images of oncological surgical specimens].
abstract: OBJECTIVE
  To design a novel ex-vivo acquisition technique to establish a common framework to validate different segmentation techniques for oncological PET images. To evaluate several automatic segmentation algorithms on this set of images.
  
  
  METHODS
  In 15 patients with cancer, ex-vivo PET studies of surgical specimens removed during surgery were performed after injection of (18)F-FDG. Images were acquired in two scanners: a clinical PET/CT and a high-resolution PET scanner. Real tumor volume was determined in each patient, and a reference image was generated for segmentation of each tumor. Images were segmented with 12 automatic algorithms and with a standard method for PET (relative threshold at 42%) and results were evaluated by quantitative parameters.
  
  
  RESULTS
  It has been possible to demonstrate by segmentation of PET images of surgical specimens that on high resolution PET images, 8 out of 12 evaluated segmentation techniques outperformed the standard method, whose value is 42%. However, none of the algorithms outperformed the standard method when applied on images from the clinical PET/CT. Due to the great interest of this set of PET images, all studies have been published on the Internet in order to provide a common framework for validation and comparison of different segmentation techniques.
  
  
  CONCLUSIONS
  We have proposed a novel technique to validate segmentation techniques for oncological PET images, acquiring ex-vivo PET studies of surgical specimens. We have demonstrated the usefulness of this set of PET images by evaluating several automatic segmentation algorithms.
authors: Departamento de Medicina Nuclear, Clínica Universidad de Navarra, Pamplona, España.
authors: E
authors: E
authors: Prieto
authors: Departamento de Medicina Nuclear, Clínica Universidad de Navarra, Pamplona, España. Electronic address: jmmartic@unav.es.
authors: J M
authors: JM
authors: Martí-Climent
authors: Departamento de Matemáticas, Universidad Pública de Navarra, Pamplona, España.
authors: M
authors: M
authors: Gómez-Fernández
authors: Departamento de Medicina Nuclear, Clínica Universidad de Navarra, Pamplona, España.
authors: M J
authors: MJ
authors: García-Velloso
authors: Departamento de Medicina Nuclear, Clínica Universidad de Navarra, Pamplona, España.
authors: M
authors: M
authors: Valero
authors: Departamento de Medicina Nuclear, Clínica Universidad de Navarra, Pamplona, España.
authors: P
authors: P
authors: Garrastachu
authors: Departamento de Oncología Radioterápica, Clínica Universidad de Navarra, Pamplona, España.
authors: J
authors: J
authors: Aristu
authors: Departamento de Ginecología y Obstetricia, Clínica Universidad de Navarra, Pamplona, España.
authors: J L
authors: JL
authors: Alcázar
authors: Departamento de Cirugía Torácica, Clínica Universidad de Navarra, Pamplona, España.
authors: W
authors: W
authors: Torre
authors: Departamento de Cirugía General y Digestiva, Clínica Universidad de Navarra, Pamplona, España.
authors: J L
authors: JL
authors: Hernández
authors: Departamento de Anatomía Patológica, Clínica Universidad de Navarra, Pamplona, España.
authors: F J
authors: FJ
authors: Pardo
authors: Departamento de Medicina Nuclear, Clínica Universidad de Navarra, Pamplona, España.
authors: I
authors: I
authors: Peñuelas
authors: Departamento de Medicina Nuclear, Clínica Universidad de Navarra, Pamplona, España.
authors: J A
authors: JA
authors: Richter
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery
keywords: Oncology; Oncología; Pieza quirúrgica; Positron emission tomography; Segmentación; Segmentation; Surgical specimen; Tomografía por emisión de positrones