Pattern of lymph node metastases and its implication in radiotherapeutic clinical target volume delineation of regional lymph node in patients with gastric carcinoma.

摘要

PURPOSE: To study the pattern of lymph node metastases (LNM) of gastric carcinoma (GC) and clarify the clinical target volume delineation of regional lymph node (CTVn). METHODS AND MATERIALS: The pattern of LNM of a total of 875 GC patients who had undergone gastrectomy and lymphadenectomy with more than 15 lymph nodes retrieved were retrospectively examined. The clinicopathologic factors related to LNM were analyzed using logistic regression analysis and linear regression. RESULTS: The rate of LNM in patients with upper GC was 75.3%, in middle ones 78.9%, in lower ones 64.9%, and 82.2% in patients with whole GCs. In terms of the ratio between metastatic and examined lymph nodes (N ratio) of GC patients, it was 35.8% in patients with upper tumors, 36.6% in middle ones, 27.6% in lower ones, and 51.0% in whole GCs. The maximum diameter and T stage of tumor emerged as statistically significant risk factors of the rate of LNM of GC (P<0.001, 0.001, respectively; HR=1.172, 2.132, respectively; 95% confidence interval: 1.083-1.268, 1.777-2.558, respectively). T stage (P<0.001), the maximum diameter of tumor (P<0.001), tumor differentiation (P=0.018) and macroscopic types of tumor (P=0.030) were significantly associated with N ratio. Our material showed an orderly spread to stations 1-16 clearly related to the position of the tumor (P<0. 001), nevertheless, there was no statistical difference between different locations of tumor with regards of the rate of LNM (P=0.614, HR=0.945, 95% confidence interval: 0.759-1.177) as well as N ratio (P>0.05). CONCLUSIONS: The pattern of LNM in GC is mainly correlated with the maximum diameter of tumor, T stage, macroscopic types and histologic differentiation. Rate of LNM and N ratio can be recommended as applicable parameters for lymph nodes involvement of GC. These factors should be considered comprehensively to design the CTVn for radiotherapy (RT) of GC. Selective regional irradiation including the correlated lymphatic drainage regions should be performed as well.