Recurrence of malignant melanoma after irradiation diagnosed by glucose-fructose enhanced magnetic resonance imaging.

Two patients who had been given ruthenium plaque treatment for uveal melanoma were MR examined due to suspected recurrence. Spin-echo sequences were applied using a 1.5 T equipment. The examinations were performed in both patients two times with a 2-h interval. Immediately after the first examination the patients were perorally given 20 g glucose and 10 g fructose. An increase of signal intensity (prolongation of the relaxation times) and size of the uveal lesions could be visualized by a subtraction technique in both patients after the carbohydrate loading. In agreement with our previous studies of malignant melanoma the changed metabolism in the uveal lesions indicated recurrence of the tumour. One eye was available for histological examination. The morphological difference between areas of recurring and degenerating tumour was clearly seen. Similar changes were not observed by ultrasound.