Relationship between positive lymph nodes and distant metastasis after intensity-modulated radiotherapy in patients with nasopharyngeal carcinoma / 中华放射肿瘤学杂志

ABSTRACT

Objective To explore the relationship between positive cervical lymph nodes and distant metastasis after intensity-modulated radiotherapy(IMRT)in patients with nasopharyngeal carcinoma(NPC). Methods A retrospective analysis was performed on the clinical data of 474 patients who were newly diagnosed with NPC but no distant metastasis and received IMRT from 2010 to 2012. The survival rates were calculated by the Kaplan-Meier method. The log-rank test was used for comparison of survival rates and univariate prognostic analysis. The multivariate analysis was made by the Cox regression model. Results In the 474 patients, 400 had positive cervical lymph nodes and 122 had residual masses in the neck after IMRT. The four-year distant metastasis, overall survival, disease-free survival, local relapse-free survival, and distant metastasis-free survival(DMFS)rates were 13.71%(65/474), 82.9%, 81.4%, 93.5%, and 86.3%, respectively. The univariate and multivariate analyses showed that treatment approach, lymph node metastases in lower neck Ⅳ/Ⅴb/Ⅴcregions, the greatest diameter of the positive cervical lymph nodes, the diameter of residual lymph nodes, and time to lymph node recession were independent prognostic factors for DMFS(all P<0.05). Conclusions Chemoradiotherapy can reduce the distant metastasis rate after IMRT for NPC. The larger the cervical lymph nodes are,the more likely there are residual masses;the larger the residual cervical lymph nodes are, the higher risk of distant metastasis there is. Large cervical lymph nodes(≥6 cm),residual masses larger than 1 cm,and residual masses at 3 months after IMRT are negative prognostic factors for DMFS after IMRT for NPC. Better intervention treatment approaches need to be explored.