Objective: 2-[18F]Fluoro-2-deoxyglucose positron emission tomography (FDG-PET) is routinely used for the diagnosis of primary lung cancer. However, the role of FDG-PET in the diagnosis and staging of small-sized lung cancer has not been sufficiently evaluated. The purpose of this study was to determine the utility of FDG-PET for preoperative staging of solid-type small-sized lung cancer manifesting as solid-component predominant nodules.
Methods: One-hundred and eighteen patients with solid-type small-sized (≤2 cm) lung cancer diagnosed as clinical stage IA based on thin-slice computed tomography (TS-CT) were included in this study. Before surgery, FDG-PET was performed in 78 patients (CT/PET group), and TS-CT alone was performed in 40 patients (CT group). Clinical and pathological stage and prognosis were retrospectively reviewed according to whether FDG-PET had been performed.
Results: No significant differences in clinical factors were observed when comparing the CT/PET group and the CT group. Of the 78 patients in the CT/PET group, 12 (15.4 %) were diagnosed with clinical stage IIA or IIIA disease based on FDG-PET findings, but no advanced cases with contraindications for curative surgery were seen. In the CT/PET group, the pathological stage was IA in 66 patients, IB in eight patients, IIA in one patient, and IIIA in three patients; 16 patients had incorrectly staged disease. The accurate staging rate was 79.5 % for the CT-PET group and 70.0 % for the CT group (P = 0.262). Among patients diagnosed with clinical stage IA disease, the 3-year overall survival rate was 85.5 % for the 66 patients in the CT/PET group and 76.8 % for the 40 patients in the CT group (P = 0.554). No significant difference was observed in accuracy of preoperative staging and prognosis between the two groups.
Conclusions: FDG-PET produced no clear benefit for the preoperative management of patients with solid-type clinical T1aN0M0 lung cancer, in terms of postoperative survival and the concordance rate of clinical and pathological stage.