Preoperative MDCT assessment for lymphatic gastric cancer spread in the era of neoadjuvant treatment

Purpose: To validate the feasibility and accuracy of MDCT for the preoperative lymphatic gastric cancer spread. Material and Methods: 104 patients with primary gastric cancer (mean age 68.67 years) who consecutively underwent MDCT scan followed by radical surgical treatment were prospectively evaluated. Regional lymph nodes were considered involved when the short-axis diameter was >5mm for the lymph nodes of group 1 and >8mm for the lymph nodes of other group according to the Japanese Classification of Gastric Carcinoma. All patients underwent a radical lymph node dissection (D2-D3) according to Japanese Research Society for Gastric Cancer (JRSGC) guidelines. The removal of nodal stations was always preceded by Indian-ink injection in the lesser and greater curvature of the stomach; after operation, single lymph nodes were retrieved on the fresh specimen by the surgeon, and classified in JRSGC nodal stations for pathological examination. Results: Lymph node invasion was found in 85 cases (81.73%) with a MDCT sensitivity and specificity of 89% and 85%, respectively. The rate of understaging was higher (15%) than that of overstaging (8%). Lymph node status of early forms was correctly staged in all cases. Furthermore, all N3 cases were correctly staged. Conclusion: MDCT is a useful technique in the preoperative assessment of lymphatic cancer spread and could have a positive impact in clinical decision making in the era of neoadjuvant treatment.