Standard uptake value of positron emission tomography in clinical stage I lung cancer: clinical application and pathological correlation

OBJECTIVES: The aim of this study was to assess the standard uptake value in clinical stage I non-small cell lung cancer (NSCLC) and its correlation with pathological status and prognosis. METHODS: We retrospectively reviewed 674 patients diagnosed with NSCLC between January 2002 and June 2005. Patients with clinical stage I diseases undergone a preoperative positron emission tomography-computed tomography scan followed by anatomic resection. We reviewed the clinical features of 152 patients with an average follow-up of 87 months. RESULTS: We analysed the clinical features of 108 patients with stage I NSCLC and 44 patients with non-stage I NSCLC. There were no statistical differences in age, histological type, location or tumour differentiation between the two groups. In the Stage I group, the patients had lower maximum standard uptake value (SUVmax; 3.80 ± 3.17 vs 5.73 ± 3.65, P = 0.001), lower carcinoembryonic antigen (CEA) levels (2.86 ± 4.80 vs 9.11 ± 17.21 ng/ml, P = 0.027) and smaller tumour size (2.39 ± 0.98 vs 3.73 ± 2.04 cm, P < 0.001). The patients with higher SUVmax had a more advanced pathological stage, poorer tumour differentiation and larger tumour size. A higher SUVmax was an independent factor predicting an advanced pathological stage (SUVmax ≥ 3.3, odds ratio 3.246). The median survival of patients with SUVmax ≥ 3.3 and SUVmax <3.3 were 64.32 and 53.08 months, respectively (P = 0.654). CONCLUSIONS: Higher preoperative 18-fluorodeoxyglucose uptake by a tumour was significantly associated with an advanced pathological stage but not correlated with a poorer prognosis. An aggressive preoperative work-up for occult N2 disease should be emphasized, avoiding inappropriate thoracotomy.