Studies of Preoperative Imaging Diagnosis for the Assessment on the Lymph Node Metastasis of Gastric Cancer

Shinichi Yamada, Kunio Okajima, Hiroshi Isozaki, Eiji Nakata, Toshikazu Kitade*, Yoshimi Komizo*

Department of Surgery, Osaka Medical College
Kitade Hospital for Gastro-Intestinal Disease*

To allow a more rational selection of a surgical procedure for gastric cancer, taking into consideration the features of lymph node metastasis, we recently assessed the usefulness of imaging techniques in the preoperative diagnosis of lymph node metastasis. Lymph node metastasis of gastric cancer was divided into four types: micronodular, diffuse and micro-focal. By using this classification, a clinicopathological analysis was conducted on 515 patients who had undergone R₂ or more extensive lymph node dissection over the past 6 years. In 206 of these patients, the findings of ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI) before the operation were compared. Of all cases of lymph node metastasis, 27.0% were of the macro-nodular type, 16.9% the micro-nodular type, 54.0% the diffuse type and 2.1% the micro-focal type. The largest diameter of the lymph nodes affected by macro-nodular type metastasis was significantly greater than that of the metastasis-free lymph nodes, while this parameter did not significantly differ between the lymph nodes showing the other types of metastasis and the metastasis-free lymph nodes. The rate of accurate diagnosis of lymph node metastasis was 55.6% with ultrasonography, 72.5% with CT and 68.6% with MRI. The rate was particularly high for nodular type metastasis. For the diagnosis of metastasis to the lymph nodes of the abdominal para-aorta, MRI of the coronal sections was useful. These findings indicate that only the macro-nodular type lymph node metastasis can be accurately diagnosed by imaging before the operation, requiring the rout of cancer metastasis to be appropriately considered in selecting a surgical procedure for gastric cancer.

Key words
preoperative imaging diagnosis, rational surgery, mode of metastasis in the lymph node

Reprint requests
Shinichi Yamada Department of Surgery, Osaka Medical College
2-7 Daigaku-cyo, Takatsuki, 569 JAPAN

Accepted
November 20, 1991

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