Role of 68Ga-DOTATOC PET/CT in initial evaluation of patients with suspected bronchopulmonary carcinoid.

PURPOSE: The objective of this study was to evaluate the role of (68)Ga-DOTATOC positron emission tomography (PET)/CT scan in patients with suspected pulmonary carcinoid tumour and to compare its results with (18)F-fluorodeoxyglucose (FDG) PET/CT scan.

METHODS: In this prospective study, 32 patients (age 34.22 ± 12.03 years; 53.1 % female) with clinical suspicion of bronchopulmonary carcinoid were evaluated with (68)Ga-DOTATOC PET/CT and (18)F-FDG PET/CT. The two imaging modalities were compared, considering the tissue diagnosis as the reference standard.

RESULTS: Based on the reference standard 26 cases were carcinoid tumours [21 typical carcinoids (TC) and 5 atypical carcinoids (AC)] and 6 cases were non-carcinoid tumours. The sensitivity, specificity and accuracy of (68)Ga-DOTATOC PET/CT in the diagnosis of pulmonary carcinoid tumour were 96.15, 100 and 96.87 % respectively, whereas those of (18)F-FDG PET/CT were 78.26, 11.1 and 59.37 % respectively. The maximum standardised uptake value (SUV max) of TC on (68)Ga-DOTATOC PET/CT scan ranged from 3.58 to 55, while that of AC ranged from 1.1 to 32.5. (18)F-FDG PET/CT was true-positive in all cases of AC and false-negative in eight cases of TC (sensitivity for TC 61.9 % and for AC 100 %).

CONCLUSION: (68)Ga-DOTATOC PET/CT is a useful imaging investigation for the evaluation of pulmonary carcinoids. (18)F-FDG PET/CT scan suffers from low sensitivity and specificity in differentiating the pulmonary carcinoids from other tumours.