title: Somatostatin receptor positron emission tomography/computed tomography imaging in Merkel cell carcinoma.
abstract: BACKGROUND
  Merkel cell carcinoma (MCC) is an uncommon aggressive primary cutaneous carcinoma with neuroendocrine differentiation. However, literature data about the use of somatostatin receptor positron emission tomography/computed tomography (PET/CT) imaging in MCC are limited and its role is not clearly stated.
  
  
  OBJECTIVE
  To investigate the role of PET/CT using somatostatin analogues radiolabelled with gallium-68 in patients with MCC.
  
  
  METHODS
  All patients affected by MCC who performed a somatostatin receptor PET/CT imaging from October 2007 to May 2014 were retrospectively analysed. The diagnostic performances of PET/CT were evaluated on a patient-based analysis and compared to final diagnosis (histology = 3 or clinical/radiological follow-up = 20).
  
  
  RESULTS
  We evaluated 23 consecutive MCC patients [18 men; median age 71 years (range 47-87)]. Primary tumour was located in ear (1/23), cheek (3/23), arm (2/23), hand (1/23), back (1/23), anal canal (1/23), gluteus (4/23), thigh (3/23) and popliteal fossa (1/23). In 6/23 patients, the site of primary tumour was unknown. PET/CT was performed to detect primary tumour site (4/23) or to stage (8/23) or re-stage (11/23) patients. PET/CT resulted positive in 14/23 patients and according to the final diagnosis was defined true positive, true negative, false positive (FP) and false negative in 11/23, 8/23, 3/23 and 1/23 cases respectively. FP PET/CT results were due to unspecific liver uptake, post-surgical inflammation and pancreatic neuroendocrine tumour. PET/CT was unable to detect primary tumour site in all patients with unknown primary MCC. Sensitivity, specificity and diagnostic accuracy of PET/CT were 92%, 73% and 83% respectively.
  
  
  CONCLUSIONS
  In our experience, somatostatin receptor PET/CT imaging resulted useful in patients with MCC and presented high diagnostic performances with a significant impact in disease management although in patients with unknown primary MCC, it was unable to identify the primary tumour site.
authors.affiliation: Nuclear Medicine Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia, Reggio Emilia, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Sollini
authors.affiliation: Institute of Nuclear Medicine, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Taralli
authors.affiliation: Division of Medical Oncology, Regina Elena National Cancer Institute, Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Milella
authors.affiliation: Regional Center of Nuclear Medicine, University of Pisa, Pisa, Italy.
authors.forename: P A
authors.initials: PA
authors.lastname: Erba
authors.affiliation: Nuclear Medicine Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia, Reggio Emilia, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Rubagotti
authors.affiliation: Nuclear Medicine Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia, Reggio Emilia, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Fraternali
authors.affiliation: Nuclear Medicine Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia, Reggio Emilia, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Roncali
authors.affiliation: Skin Cancer Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia, Reggio Emilia, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Moscarella
authors.affiliation: Institute of Nuclear Medicine, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Perotti
authors.affiliation: Institute of Nuclear Medicine, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Rufini
authors.affiliation: Nuclear Medicine Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia, Reggio Emilia, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Versari
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015266:Carcinoma, Merkel Cell / Q000000981:diagnostic imaging* / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D017481:Receptors, Somatostatin / Q000378:metabolism*; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D014057:Tomography, X-Ray Computed
chemical_list: D017481:Receptors, Somatostatin