FUKUDA Hiroshi Institute of Development, Aging and Cancer, Tohoku University, Professor., 加齢医学研究所, 教授 (30125645)
KANAMURA Ryunosuke Institute of Development, Aging and Cancer, Tohoku University, Professor., 加齢医学研究所, 教授 (70152783)
The development of positron emission tomomgraphy (PET) has made it possible to obtain metabolic image of living bodies with proper tracers. Fluorine-18-2-deoxy-2-fluoro-D-glucose (FDG), a structural analo like glucose, is a PET tracer for the glycolytic metabolism and has been widely used in oncology because increased glycolysis is one of the most important characteristics of cancer cells.
PET with FDG (FDG-PET) has been used to image successfully various kinds of hum an neoplasms, however, its application for stomach neoplasms has been limited. The first aim of this study was to evaluate the visual diagnostic accuracy of FDG-PET for the diagnosis of the progressions in patients with aidvanced, metastatic or recurrent gastric cancer and to generate semiquantitative values for lesions.
FDG-PET scans were obtained on 42 patients : 20 patients with a PT931/04 scanner that covers 15 cm above and below the targeted lesion, and 22 patients with a SET 2400W scanner that images entire body A II
PET images were interpreted visually, and tracer uptakes were quantitated as standardized uptake values (SUYs) on SET 2400W images. The sensitivity, specitivity, and accuracy as a whole were as follow 71%, 74%, and 73%, respectively, with the SWT2400W scanner and 47%, 79%, and 62%, redspectively, with the PT931/04 scanner. Values were high for primary lesions, liver, lymphnode, and lung metastases, bu were low for bone metastases, ascites, peritonitis, and pleuritis carcinom atoses. Comparing SUVs and histologic finding for 17 untreated patients, values for well-differentiated and moderately differentiated adenocarcinom as were higher than poorly differentiated adenocarcinomas as and signet ring cell carcinomas. Our results indicate that FDG-PET is a useful diagnostic modality for the advanced, metastatic, orrecurrent gastric cancer but not for detecting bone metastases, peritinitis, or pleuritis carcinom atoses. FDG uptake by gastric cancers is relatively high but does not parallel histopathologic features of malignancy.
The second aim of this study is to clarify if PET is useful for the evaluation for the efficacy of molecular targeted agents, but data has not been obtained yet. Less