Experimental study for cancer diagnosis with ¹⁸FDG: Differential diagnosis of inflammation from malignant tumor

The validity of tumor diagnosis with ¹⁸FDG was tested in an experimental rabbit tumor. A male rabbit with a VX2 tumor in the right thigh and croton oil-induced inflammation in the left thigh, was injected with 3 mCi of ¹⁸FDG. Just after injection, serial scanning every 3 min was done by positron emission tomography. The total number of images was 20 and each image had no less than 500 k counts. The tumor uptake of ¹⁸FDG was high and increased with time during the 60-min study period. Inflammation uptake was lower than that of tumor and relatively constant during the period. This was the important finding that distinguishes inflammation from a malignant tumor and it would be useful information for clinical cancer diagnosis with ¹⁸FDG.