title: Efficiency of 18F-FDG and 99mTc-depreotide SPECT in the diagnosis of malignancy of solitary pulmonary nodules.
abstract: OBJECTIVE
  The purpose of the study was to compare ( 18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and ( 99m)Tc-depreotide single-photon emission computed tomography (SPECT) in the diagnosis of malignancy of solitary pulmonary nodules (SPNs).
  
  
  METHODS
  Twenty-eight patients without any history of cancer and presenting an SPN (0.8-3 cm in size) underwent FDG PET and depreotide SPECT. Depreotide SPECT and FDG PET were performed on a double-head gamma camera and a dedicated PET scanner respectively. Twenty-five out of 28 lesions were removed by thoracotomy or assessed by biopsy (n=1) and histologically examined. A strategy of serial CT scanning was adopted in the three remaining patients.
  
  
  RESULTS
  Histological findings revealed 18 malignant nodules and seven benign lesions. Stability over a 2-year period indicated a benign process in the remaining three cases. Both techniques yielded true positive results in 15 of the 18 cancers. FDG PET identified two additional adenocarcinomas not detected by depreotide SPECT. A carcinoid tumour not visualised on FDG PET was identified by depreotide SPECT. Seven of the ten benign lesions did not reveal tracer uptake on either depreotide SPECT or FDG PET. Both techniques showed false positive results for the same two lesions. One more false positive was seen on FDG PET. FDG PET and depreotide SPECT had a sensitivity of 94.4% and 88.9% respectively; this difference was not significant. In our experience, depreotide SPECT and FDG PET are equally sensitive (92.3%) for large (>1.5 cm) and equally specific (85.7%) for small (up to 1.5 cm) SPNs suspicious for malignancy.
  
  
  CONCLUSIONS
  This study showed( 18)F-FDG PET to be more sensitive than ( 99m)Tc-depreotide SPECT in the diagnosis of malignancy of SPNs. However, the combination of both techniques may provide additional accuracy.
authors.affiliation: Department of Nuclear Medicine, University Hospital, Avenue de la cote de Nacre, 14033 Caen, France. halley-a@chu-caen.fr
authors.forename: Arnaud
authors.initials: A
authors.lastname: Halley
authors.forename: Alexis
authors.initials: A
authors.lastname: Hugentobler
authors.forename: Philippe
authors.initials: P
authors.lastname: Icard
authors.forename: Emilie
authors.initials: E
authors.lastname: Porret
authors.forename: Franck
authors.initials: F
authors.lastname: Sobrio
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Lerochais
authors.forename: Gerard
authors.initials: G
authors.lastname: Bouvard
authors.forename: Gerard
authors.initials: G
authors.lastname: Zalcman
authors.forename: Denis
authors.initials: D
authors.lastname: Agostini
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D005602:France; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010865:Pilot Projects; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D013004:Somatostatin / Q000031:analogs & derivatives*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D013004:Somatostatin; C444119:technetium Tc 99m depreotide