title: Diagnostic accuracy of ¹¹C-choline PET/CT in comparison with CT and/or MRI in patients with hepatocellular carcinoma.
abstract: OBJECTIVE
  In recent decades, the use of radiopharmaceuticals in the assessment of hepatocellular carcinoma (HCC) has become established, and new findings indicate that radiolabelled choline has considerable potential in this setting. Therefore, in this study we aimed to assess the diagnostic role of (11)C-choline positron emission tomography (PET)/CT, compared with conventional imaging with CT/MRI, in patients with HCC.
  
  
  METHODS
  The study population comprised 45 patients (male to female ratio = 37:8, median age 70.5 years) referred to our institution owing to HCC: 27 at initial diagnosis and 18 for restaging after recurrence. In all cases we performed whole-body (11)C-choline PET/CT and compared its findings with contrast-enhanced CT (n = 35) or MRI (n = 29) or both (n = 15) for a total of 50 paired scans. The reference standard was either histological proof (21 patients) or a multidisciplinary consensus. Diagnostic accuracy was then determined in a scan-based (SBA) and a lesion-based analysis (LBA).
  
  
  RESULTS
  On SBA the sensitivity and specificity for PET were 88 and 90 %, respectively, whereas for CT/MRI they were 90 and 73 %, respectively (p > 0.05). On LBA the overall sensitivity and specificity were 78 and 86 %, respectively, for PET vs 65 and 55 % for CT/MRI. Overall we investigated 168 disease sites, of which 100 were in the liver and 68 were extrahepatic. When considering only liver lesions, (11)C-choline PET and CT/MRI showed an accuracy of 66 and 85 %, respectively, while for extrahepatic lesions PET showed an accuracy of 99 %, while the accuracy of CT/MRI was 32 %. In both cases, there was a statistically significant difference in accuracy between the two modalities (p < 0.01). Combination of the PET results with those of CT/MRI resulted in the highest diagnostic accuracy in both analyses, at 92 % for SBA and 96 % for LBA. In 11 patients (24 %) the PET findings modified the therapeutic strategy, the modification proving appropriate in 10 of them.
  
  
  CONCLUSIONS
  (11)C-Choline PET showed good accuracy in investigating patients with HCC and prompted a change in treatment planning in almost one fourth of patients. The main strength of (11)C-choline PET/CT resides in its ability to detect extrahepatic HCC localizations, but the combination with conventional imaging modalities allowed for the highest diagnostic accuracy.
authors.affiliation: Nuclear Medicine Department, Humanitas Clinical and Research Center, Rozzano, MI, Italy, egesta.lopci@gmail.com.
authors.forename: Egesta
authors.initials: E
authors.lastname: Lopci
authors.forename: Guido
authors.initials: G
authors.lastname: Torzilli
authors.forename: Dario
authors.initials: D
authors.lastname: Poretti
authors.forename: Lauro J Souza
authors.initials: LJ
authors.lastname: de Neto
authors.forename: Matteo
authors.initials: M
authors.lastname: Donadon
authors.forename: Lorenza
authors.initials: L
authors.lastname: Rimassa
authors.forename: Ezio
authors.initials: E
authors.lastname: Lanza
authors.forename: Juliano Guerra
authors.initials: JG
authors.lastname: Sabongi
authors.forename: Roberto
authors.initials: R
authors.lastname: Ceriani
authors.forename: Nicola
authors.initials: N
authors.lastname: Personeni
authors.forename: Angela
authors.initials: A
authors.lastname: Palmisano
authors.forename: Vittorio
authors.initials: V
authors.lastname: Pedicini
authors.forename: Tiziana
authors.initials: T
authors.lastname: Comito
authors.forename: Marta
authors.initials: M
authors.lastname: Scorsetti
authors.forename: Arturo
authors.initials: A
authors.lastname: Chiti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002250:Carbon Radioisotopes; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002794:Choline; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D002250:Carbon Radioisotopes; D002794:Choline