POSITRON EMISSION TOMOGRAPHY WITH F-18 FLUORODEOXYGLUCOSE TO EVALUATETHE RESULTS OF HEPATIC CHEMOEMBOLIZATION

BACKGROUND. Positron emission tomography (PET) using F-18-fluorodeoxyg lucose ((18)FDG) is an imaging modality allowing direct evaluation of cellular glucose metabolism. The purpose of this study was to examine the role of (18)FDG-PET in monitoring chemoembolization therapy of pat ients with liver metastases from adenocarcinoma. METHODS. Thirty-four hepatic lesions in 4 patients were evaluated with (18)FDG-PET before a nd 2-3 months after interventional therapy. All patients underwent tra nscatheter arterial chemoembolization. A total of nine PET studies wer e performed. Semiquantitative measurement of the metabolic activity of the lesions was performed using the standard uptake value (SUV) of (1 8)FDG. Comparison was performed between sequential PET scans using Stu dent's t test for paired data analysis. The PET findings were also com pared with tumor marker levels measured at the time of the PET scans. RESULTS. Twenty-five of 34 lesions had decreased (18)FDG uptake (SUV = 8 +/- 2 vs. 3 +/- 1; P < 0.00001), as expected in successful tumor ch emoembolization. These findings were associated with a significant dec rease in serum tumor marker levels (86 +/- 4%; P < 0.05) after treatme nt. However, there were 3 new lesions, and 6 of the 34 lesions demonst rated persistent or increased (18)FDG uptake after treatment (SUV = 8 +/- 2 vs. 13 +/- 3; P < 0.05), consistent with the presence of residua l viable tumor. These findings led to further interventional therapy i n all patients. CONCLUSIONS. (18)FDG-PET allows monitoring of response to treatment with hepatic chemoembolization in patients with liver me tastases from adenocarcinoma. PET is a useful diagnostic tool and has the potential to be used to guide further interventional therapy. (C) 1996 American Cancer Society.