Preoperative 18F-fluorodeoxyglucose positron emission tomography can predict the tumor malignancy of small peripheral lung cancer.

PURPOSE Recent advances in image diagnostic technology have enhanced the discovery of peripheral small size lung cancers. Here, we examined the utility of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) for the evaluation of grade of tumor malignant potency. METHODS Seventy-nine patients with peripheral small lung cancers (≤2 cm) who underwent surgical resections and preoperative FDG-PET were enrolled. The correlations between the maximum standardized uptake value (SUVmax) and various clinicopathological features related to tumor invasiveness, nodal metastasis, and recurrence were analyzed. RESULTS The median SUVmax of all tumors was 2.4 (range, 0-16.1). The SUVmax was significantly higher in patients with vascular invasion (5.6 ± 3.5 vs. 2.4 ± 2.4; P <0.0001), lymphatic invasion (4.9 ± 3.7 vs. 2.7 ± 2.6; P = 0.0029), lymph node metastasis (6.1 ± 4.4 vs. 3.0 ± 2.7; P = 0.0022), and recurrences (5.8 ± 3.3 vs. 3.1 ± 3.1; P = 0.0219). Patients with SUVmax ≥2.5 had a significantly higher incidence rate of vascular invasion (56% vs. 7%; P <0.0001), lymphatic invasion (51% vs. 15%; P = 0.0006), lymph node metastasis (26% vs. 3%; P = 0.0033), and recurrence (18% vs. 3%; P = 0.0289). The patients with SUVmax ≥1.5 also had a significantly higher incidence of vascular invasion, lymphatic invasion, lymph node metastasis, and recurrence. It is particularly worth noting that patients with SUVmax <1.5 had no vascular invasion, lymph node metastasis, or recurrence. CONCLUSION Preoperative SUVmax of peripheral small lung cancers were significantly associated with tumor malignancy.