Contrast-enhanced computed tomography versus positron emission tomography/positron emission tomography-computed tomography in suspected lung cancer: a systematic review and meta-analysis of diagnostic accuracy studies

Background: There is uncertainty regarding the optimal next imaging modality for identifying likely malignant pulmonary lesions in patients with abnormal chest radiography, with or without respiratory symptoms. Objectives: We compared the diagnostic accuracy of chest contrast-enhanced computed tomography (CECT) and positron emission tomography or positron emission tomography-computed tomography (PET/PET-CT) for identifying malignant pulmonary lesions. Design: Systematic review and meta-analysis Data sources and methods: We searched the PubMed, Embase, Scopus, and Cochrane CENTRAL databases to identify head-to-head diagnostic accuracy studies comparing CECT and PET/PET-CT for their ability to differentiate between benign and malignant pulmonary lesions. The risk of bias of included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies – Comparative (QUADAS-C) tool. Meta-analysis was performed using the bivariate random effects model. Results: We included eight studies, comprising a total of 873 subjects. The pooled sensitivity and specificity of CECT (850 lesions) were 0.93 (95% CI, 0.89–0.96; I 2 = 24.99%) and 0.54 (95% CI, 0.32–0.75; I 2 = 84.00%). The pooled sensitivity and specificity of PET/PET-CT (851 lesions) were 0.87 (95% CI, 0.78–0.93; I 2 = 65.15%) and 0.83 (95% CI, 0.63–0.94; I 2 = 73.23%). Compared to CECT, PET/PET-CT had a lower relative sensitivity (relative ratio [RR], 0.93; 95% CI, 0.89–0.97; p < 0.01) and a higher relative specificity (RR, 1.69; 95% CI, 1.18–2.41; p < 0.01). After excluding the study with the largest sample size, PET/PET-CT was not less sensitive than CECT (RR, 0.99; 95% CI, 0.94–1.04; p = 0.73). There was a high/unclear risk of bias and applicability concerns in the population domain in six out of eight studies. Conclusions: Based on limited evidence with applicability concerns, CECT of the chest may have a higher sensitivity but lower specificity than PET/PET-CT for identifying malignant lesions among patients with suspected lung cancer. Trial registration: The protocol for the systematic review was prospectively registered on PROSPERO (CRD42024590904)