The maximum standardized uptake values on positron emission tomography to predict the Noguchi classification and invasiveness in clinical stage IA adenocarcinoma measuring 2 cm or less in size.

This study investigated whether the standardized uptake value (SUV) of the tumor correlated with the Noguchi classification and tumor invasiveness in patients with clinical stage IA adenocarcinoma < or = 2 cm in size. Fifty-four patients that underwent a curative surgical resection for clinical stage IA adenocarcinoma < or = 2 cm from April 2005 to December 2008 had integrated positron emission tomography (PET)-computed tomography (CT) with 18F-fluorodeoxyglucose (FDG) as part of the preoperative workup. The relationships between the maximum SUV (SUVmax) and Noguchi classification, pathological results of intratumoral lymphatic or vascular invasion of tumor cells, and pleural invasion were examined. In comparison to tumors with an SUVmax>1.0, tumors with an SUVmax < or = 1.0 were more frequently classified as Noguchi type A or B (P<0.0001). Tumors with an SUVmax>1.0 had more intratumoral lymphatic or vascular invasion of tumor cells and pleural invasion (P=0.0005 and P=0.0002). These results suggest that an SUVmax is an important predictor for the Noguchi classification and tumor invasiveness in patients with clinical stage IA adenocarcinoma < or =2 cm in size.