GLUCOSE-METABOLISM AND PATHOLOGICAL FINDINGS IN UVEAL MELANOMA - PRELIMINARY-RESULTS

The aims of this study were to assess the sensitivity of positron emis sion tomography (PET) using [F-18]fluorodeoxyglucose (F-18-FDG) in the detection of uveal melanoma, and to establish the relationship betwee n pre-operative F-18-FDG uptake and a number of pathological features of uveal melanoma. Twenty consecutive patients with a clinical diagnos is of uveal melanoma were enrolled in the study. F-18-FDG uptake was a ssessed in all subjects and the following parameters were assessed in 11 enucleated subjects: the mitotic index, the MIB-1 proliferating cel l index, number of epithelioid cells, largest tumour diameter, tumoral necrosis and inflammatory infiltration. Tumors with a diameter less t han 7.5 mm were not detected by PET, possible because of limited spati al resolution, and only 7 of 12 tumours with a diameter greater than 7 .5 mm were detected. With tumours greater than 7.5 mm in diameter, PET and F-18-FDG allow two subgroups to be distinguished: those with high and those with low glucose consumption. Apart from tumour size, F-18- FDG uptake was not related to the pathological features examined. We h ypothesize that F-18-FDG uptake may be related to the ratio of viable to non-viable cells, or to the hypoxic cell fraction within the tumour .