Detection efficacy of analog [ 18 F]FDG PET/CT, digital [ 18 F]FDG, and [ 13 N]NH 3 PET/CT: a prospective, comparative study of patients with lung adenocarcinoma featuring ground glass nodules

Objectives This prospective study compared the detection efficacy of analog 18 F-fluoro-2-deoxyglucose ( 18 F-FDG) positron emission tomography (PET)/computed tomography (CT) (aF PET/CT), digital [ 18 F]FDG PET/CT (dF PET/CT), and digital 13 N-ammonia ( 13 N-NH 3 ) PET/CT (dN PET/CT) for patients with lung adenocarcinoma featuring ground glass nodules (GGNs). Methods Eighty-seven patients with lung adenocarcinoma featuring GGNs who underwent dF and dN PET/CT were enrolled. Based on the GGN component, diameter, and solid-part size, 87 corresponding patients examined using aF PET/CT were included, with age, sex, and lesion characteristics closely matched. Images were visually evaluated, and the tumor to background ratio (TBR) was used for semi-quantitative analysis. Results Ultimately, 40 and 47 patients with pure GGNs (pGGNs) and mixed GGNs (mGGNs), respectively, were included. dF PET/CT revealed more positive lesions and higher tracer uptake in GGNs than did aF PET/CT (53/87 vs. 26/87, p < 0.05; TBR: 3.08 ± 4.85 vs. 1.42 ± 0.93, p < 0.05), especially in mGGNs (44/47 vs. 26/47, p < 0.05; TBR: 4.48 ± 6.17 vs. 1.78 ± 1.16, p < 0.05). However, dN PET/CT detected more positive lesions than did dF PET/CT (71/87 vs. 53/87, p < 0.05), especially in pGGNs (24/40 vs. 9/40, p < 0.05). Conclusions dF PET/CT provides superior detection efficacy over aF PET/CT for patients with lung adenocarcinoma featuring GGNs, particularly mGGNs. dN PET/CT revealed superior detection efficacy over dF PET/CT, particularly in pGGNs. aF, dF, and dN PET/CT are valuable non-invasive examinations for lung cancer featuring GGNs, with dN PET/CT offering the best detection performance. Key Points • Digital PET/CT provides superior detection efficacy over analog PET/CT in patients with lung adenocarcinoma featuring GGNs. • dN PET/CT can offer more help in the early detection of malignant GGN.