IS Case 314: Gastric carcinoma

Richard Gong, MD

Imaging Sciences URMC 2009
Publication Date: 2009-09-14

History

Patient is a 37-year-old female presenting after recent diagnosis of gastric carcinoma for staging PET-CT.

Findings

CT demonstrates thickening of the gastric wall with infiltrative changes in the adjacent fat. The gastric wall is hypermetabolic on PET.

Diagnosis

Gastric carcinoma

Discussion

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.

References

  1. Lee JKT, Sagel SS, Stanley RI. Computed Body Tomography with MRI Correlation. 4th ed., Lippincott Williams & Wilkins, 2003.
  2. Hassan, I. Gastric Carcinoma. Emedicine Oct 19, 2006. http://emedicine.medscape.com/article/375384-overview
  3. Yoshioka T, Yamaguchi K, Kubota K, et al. Evaluation of 18F-FDG PET in patients with advanced, metastatic, or recurrent gastric cancer. J Nucl Med. 2003 May;44(5):690-9. PMID: 12732669

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