Background: Pulmonary carcinoids (PC) are histologically classified into typical carcinoid (TC) and atypical carcinoid (AC). The diagnosis of pulmonary carcinoid and possibly the differentiation between TC and AC could make a significant effect on the treatment planning as well as prognosis. Several studies have explored the utility of Ga-DOTA-Peptide (Ga-labelled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-peptide) and F-flurodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in the evaluation of primary pulmonary carcinoids. Therefore, we performed a meta-analysis to evaluate the diagnostic accuracy and prediction efficiency of histological subtypes of these two imaging modalities in primary PC.
Methods: Relevant studies were identified by searching PubMed, Web of Science, and EMBASE published from 2006 to 2016. Two authors extracted characteristics of patients and their lesions using predefined criteria.
Results: Fourteen studies comprising 352 patients were included in this meta-analysis. The pooled sensitivity of Ga-DOTA-Peptide and F-FDG PET/CT in detecting pulmonary carcinoid were 90.0% (95% CI = 82.0-95.0%; P = .07; I = 49.6%) and 71.0% (95% CI = 66.0-76.0%; P < .001; I = 59.3%), respectively. An SUVmax ratio between Ga-DOTA-Peptide and F-FDG higher than the cutoff value of 4.28 was predictive of TC with 89.3% sensitivity and 100% specificity (AUC, 96.4%; 95% CI, 91.1-100%). The ratio of tumor uptake to atelectatic lung uptake was significantly higher for Ga-DOTA-peptide (2.5-91, mean 30.5 ± 28.1) than for F-FDG (0.3-10.3, mean 2.1 ± 2.3) (P < .001).
Conclusions: Both Ga-DOTA-peptide and F-FDG are highly sensitive in detecting pulmonary carcinoid, while Ga-DOTA-peptide is more sensitive than F-FDG (90.0% vs 71.0%). The SUVmax ratio was an accurate predictor of the histopathologic variety of the carcinoid tumor, and Ga-DOTA-peptide was better than F-FDG in cases with atelectasis.