Evaluation of 64-Channel Contrast-Enhanced Multi-detector Row Computed Tomography for Preoperative N Staging in cT2-4 Gastric Carcinoma.

ABSTRACT

BACKGROUND: Preoperative N staging is essential for the best treatment planning in patients with gastric carcinoma. The aim of this study was to evaluate the accuracy of preoperative N staging using contrast-enhanced multi-detector row computed tomography (CE-MDCT) in patients with resectable cT2-4 gastric carcinoma. METHODS: A total of 218 patients who underwent a gastrectomy with D2 lymphadenectomy for previously untreated cT2-4 primary gastric carcinoma were studied. Preoperative N staging was performed according to the 7th (UICC) TNM Staging System using pre-specified criteria on a 64-channel CE-MDCT and was compared with postoperative pathologic N staging. RESULTS: In all 218 patients, a distal or total gastrectomy was performed. The overall accuracy of the preoperative N staging was 46.3% (101/218), with the proportion of over- and under-staging being 26.6% (58/218) and 27.1% (59/218), respectively. The sensitivity, specificity, and accuracy for lymph node metastasis (≥pN1) were 79.1% (106/134), 50.0% (42/84), and 67.9% (148/218), respectively. The sensitivity, specificity, and accuracy for multiple lymph node metastases (≥pN2) were 80.2% (73/91), 68.5% (87/127), and 73.4% (160/218), respectively. Multivariate analyses showed that macroscopic type 2 and ≥6 cm-sized tumors were associated with preoperative over-N staging, while macroscopic type 1/3 tumors were associated with under-N staging. CONCLUSION: Preoperative N staging with pinpoint accuracy is difficult. However, CE-MDCT offers a reasonably high sensitivity and specificity for ≥pN2 and may be useful for selecting candidates for neoadjuvant therapies. The macroscopic type and size of the primary tumor may affect the accuracy of preoperative N staging.