Fluorodeoxyglucose uptake correlates with the growth pattern of small peripheral pulmonary adenocarcinoma.

PURPOSE

Noguchi and colleagues reported that the growth pattern of small-sized adenocarcinoma was related to the vascular involvement and the prognosis of the patient. Noguchi's type A/B tumors had no lymph node metastasis, rare vascular involvement, and an excellent prognosis, which meant that Noguchi's type A/B tumors were preinvasive tumors of the peripheral type. Although Noguchi's classification was usually determined based on resected specimens, it would be useful to make a decision about the therapeutic strategy if the classification could be determined preoperatively based on the fluorodeoxyglucose (FDG) uptake.

METHODS

The FDG uptake in 61 pulmonary adenocarcinomas measuring 3 cm or smaller in diameter was compared with the mediastinal uptake and was classified into five grades. The relationship between the FDG uptake and Noguchi's classification (A to F) was analyzed.

RESULTS

The FDG uptake was significantly lower in Noguchi's type A/B tumors than in type C or in type D/E/F. Eleven of 12 tumors (92%) with no increased or a weak FDG uptake were classified as type A/B, whereas 32 of 33 tumors (97%) with a strong or very strong FDG uptake were classified as type C-F.

CONCLUSIONS

The FDG uptake is helpful for making an accurate diagnosis of Noguchi's classification preoperatively in patients with pulmonary adenocarcinoma.