FDG PET in the evaluation of the aggressiveness of pulmonary adenocarcinoma: correlation with histopathological features

2-[Fluorine-18]fluoro-2-deoxy-d-glucose (FDG) uptake within the primary les ion correlates with survival on positron emission tomography (PET) studies of patients with non-small cell lung cancer. The more metabolically active the tumour, the worse the outcome. The aim of this study was to determine w hether a correlation exists between aggressiveness as determined by patholo gy and the findings of FDG PET in pulmonary adenocarcinoma. Thirty-five pat ients with 38 adenocarcinomas of the lung were studied. All patients underw ent thoracotomy within 4 weeks of the FDG PET study. For semiquantitative a nalysis, standardized uptake values (SUVs) were calculated. Patients were c lassified into high SUV (greater than or equal to 4.0) and low SUV (<4.0) g roups. The degree of FDG uptake (SUVs) in primary lung lesions was correlat ed with the histopathological features of aggressiveness (pleural involveme nt, vascular invasion or lymphatic permeation). The mean SW of aggressive a denocarcinomas (4.36+/-1.94,n =22) was higher than that of non-aggressive o nes (1.53 +/- 0.88, n = 16) (P <0.0001). Tumours with a high FDG uptake hav e a significantly higher likelihood of aggressiveness than those with a low FDG uptake (P = 0.0004). Analysis by the Kaplan-Meier methods revealed tha t the groups had different prognoses (log-rank test, P = 0.0099). The high SUV group had a significantly worse prognosis. In conclusion, a correlation was seen between aggressiveness as determined by pathology and glucose met abolism as measured by FDG PET in adenocarcinoma of the lung. FDG PET may b e used as a non-invasive diagnostic technique in measuring aggressiveness a nd prognosis in patients with pulmonary adenocarcinoma. ((C) 2000 Lippincot t Williams & Wilkins).