The utility of (18)F-FDG and (68)Ga-DOTA-Peptide PET/CT in the evaluation of primary pulmonary carcinoid: A systematic review and meta-analysis

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 (68)Ga-DOTA-Peptide ((68)Ga-labelled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-peptide) and (18)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 (68)Ga-DOTA-Peptide and (18)F-FDG PET/CT in detecting pulmonary carcinoid were 90.0% (95% CI = 82.0–95.0%; P = .07; I(2) = 49.6%) and 71.0% (95% CI = 66.0–76.0%; P < .001; I(2) = 59.3%), respectively. An SUVmax ratio between (68)Ga-DOTA-Peptide and (18)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 (68)Ga-DOTA-peptide (2.5–91, mean 30.5 ± 28.1) than for (18)F-FDG (0.3–10.3, mean 2.1 ± 2.3) (P < .001). CONCLUSIONS: Both (68)Ga-DOTA-peptide and (18)F-FDG are highly sensitive in detecting pulmonary carcinoid, while (68)Ga-DOTA-peptide is more sensitive than (18)F-FDG (90.0% vs 71.0%). The SUVmax ratio was an accurate predictor of the histopathologic variety of the carcinoid tumor, and (68)Ga-DOTA-peptide was better than (18)F-FDG in cases with atelectasis.