Lymph-node metastases: efficacy for detection with helical CT in patients with gastric cancer.

PURPOSE

To determine the efficacy of helical computed tomography (CT) in the detection of lymphadenopathy in patients with gastric cancer.

MATERIALS AND METHODS

Helical CT (5-mm section thickness, 5-mm/sec table incrementation) was performed in 58 patients (39 men, 19 women; mean age, 63.8 years) with gastric cancer; 1,082 lymph nodes (138 positive, 944 negative for metastasis) were resected at surgery. Findings at CT and resection were compared. Sensitivity for detecting lymph nodes was evaluated according to nodal size and presence of metastasis.

RESULTS

Seven (1.1%) of 649 lymph nodes 1-4 mm, 160 (45.1%) of 355 nodes 5-9 mm, and 56 (72%) of 78 nodes larger than 9 mm were detected at CT. For nodes of at least 5 mm, sensitivity for detecting metastasis-positive nodes (79 [75.2%] of 105 nodes) was higher than that for detecting metastasis-negative nodes (137 [41.8%] of 328; P < .01). Differences between positive and negative nodes in CT attenuation (110 HU +/- 25 vs 66 HU +/- 32) and short-to-long axis ratios (0.81 +/- 0.15 vs 0.57 +/- 0.15; P < .001) were significant.

CONCLUSION

Helical CT is effective for detection of metastatic lymphadenopathy from gastric cancer. CT attenuation and lymph-node configuration aid in diagnosis of malignant adenopathy.