@misc{oai:repo.qst.go.jp:00068006,
 author = {Tamura, Katsumi and Yoshikawa, Kyosan and Sagou, Kenji and Mizoe, Junetsu and Tsujii, Hirohiko and et.al and 田村 克巳 and 吉川 京燦 and 佐合 賢治 and 溝江 純悦 and 辻井 博彦},
 month = {Jun},
 note = {Objectives:L-[methyl-11-C] methionine(11C-MET)is a tracer for PET that can be use to assess metabolism of amino acid in tumor cells.Methionine is needed for protein synthesis,and in cancer cells the rate of protein synthesis and transmethylation is high.The orbita is close to brain,and 11C-MET is less accumulated in the normal brain compared with 18F-FDG. Therefore,11C-MET is less influenced by the accumulation of the brain than 18F-FDG.There have not been PET studies concerned with the choroidal malignant melanoma.The purpose of this study is to assess the ability of 11C-MET PET to evaluate choroidal malignant melanoma.
Methods:We studied consecutive 31 patients with the choroidal malignant melanoma who had been referred to our hospital for carbon ion beam therapy in 2001-2003.14 patients were female and 17 patients were male. The average patient age was 56.9 years (range 28 to 85).We evaluated the lesion semiquantitatively on the basis of the Tumor-To-Brain Ratio (TBR) obtained as follows.The regions of interest (ROI) were placed in the choroidal primary lesion,including the highest uptake area (circle ROI, 4x4 pixels) and bilateral cerebellum (or occipital lobe) areas on the same slice.TBR was calculated by dividing the mean radioactivity of the tumor ROI by that of the bilateral cerebellum (or occipital lobe) ROI.
Results:The size of choroidal lesion averraged 12.7mm (土3.29 SD) on the MRI,ranged 5 to 18mm.30 choroidal lesions were positive (96.8%) on the static image of 11C-MET-PET.The TBR averaged 1.76 (土0.69 SD),ranged 0.38 to 3.17.TBR and tumor size of only one negative lesion on 11C-MET-PET was 0.38 and 5mm respectively.There was no correlation between TBR and tumor size (R2=0.40).
Conclusions:Except the lachrymal gland,there is no tissue in the orbital cavity that 11C-MET is normally accumulated. 11C-MET-PET has shown good detectability (96.8%) for the choroidal malignant melanoma on the static image., Society of nuclear medicine's 51st. annual meeting},
 title = {IMAGING OF THE CHOROIDAL MALIGNANT MELANOMA USING L-[METHYL-11-C]METHIONINE PET(MET-PET).},
 year = {2004}
}