IS Case 314: Gastric carcinoma
Imaging Sciences URMC 2009
Publication Date: 2009-09-14
Gastric adenocarcinoma accounts for approximately 95% of the malignant lesions of the stomach. It is more common in men than women and most often occurs in the 6th to 8th decades of life. However 1% of patients with gastric carcinoma are younger than 30 and younger patients have poorer prognosis.
There are four histologic types: mucinous, signet-ring cell, papillary and tubular. Staging is by the TNM system with stage 1 disease associated with 88% 5-year survival and stage 4 with 5% 5-year survival.
On PET imaging standard uptake values (SUV) for gastric carcinoma are relatively high compared to other cancers (5-16 in one study). In addition, SUVs for highly differentiated gastric carcinomas are higher than poorly differentiated primary tumors and lymph node metastases. However correlation between 18-FDG uptake and histologic subset still needs further investigation. A major role of PET imaging is with treatment response. Successful treatment leads to improvement followed by normalization of 18-FDG uptake.
Treatment is usually surgery with or without a combination of chemotherapy or radiotherapy depending on the stage of the disease. For inoperable obstructing lesions, covered metallic stents can be used for palliation.
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