LAUSR

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.[1] Several studies have explored the utility of 68Ga-DOTA-Peptide (68Ga-labelled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-peptide) and 18F-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 68Ga-DOTA-Peptide and 18F-FDG PET/CT in detecting pulmonary carcinoid were 90.0% (95% CI = 82.0–95.0%; P = .07; I2 = 49.6%) and 71.0% (95% CI = 66.0–76.0%; P < .001; I2 = 59.3%), respectively. An SUVmax ratio between 68Ga-DOTA-Peptide and 18F-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 68Ga-DOTA-peptide (2.5–91, mean 30.5 ± 28.1) than for 18F-FDG (0.3–10.3, mean 2.1 ± 2.3) (P < .001). Conclusions: Both 68Ga-DOTA-peptide and 18F-FDG are highly sensitive in detecting pulmonary carcinoid, while 68Ga-DOTA-peptide is more sensitive than 18F-FDG (90.0% vs 71.0%). The SUVmax ratio was an accurate predictor of the histopathologic variety of the carcinoid tumor, and 68Ga-DOTA-peptide was better than 18F-FDG in cases with atelectasis.