ABSTRACT
Background and purpose:In 2013, the ofifcial journal of European Society of Radiotherapy &Oncology (ESTRO) -Radiotherapy & Oncology published the updated version of Consensus Guidelines of Delineation of the neck node levels for head and neck tumors, which contributed to the standardization of description of neck nodal metastasis, as well as reduction of treatment variations from various institutions. This study applied this updated guidelines to analyze the patterns of lymph node metastasis of nasopharyngeal carcinoma and explore the prognostic value of the radiologic characteristics of nodes, in order to provide evidence for future revision of N staging system. Methods:A total of 656 patients from Jan. 2009 to Dec. 2010 were retrospectively recruited to analysis. All were pathologically diagnosed as non-metastatic nasopharyngeal carcinoma, treated with intensity-modulated radiotherapy. All patients received a pretreatment MRI scan. We retrospectively reviewed the MRI imaging of 656 patients and mapped the lymph node metastasis using the 2013 International Consensus Guidelines.Results:Median follow-up was 46.9 months. Four-year local recurrence-free survival, nodal recurrence-free survival, distant metastasis-free survival, disease-free survival and overall survival was 91.3%, 95.1%, 87.7%, 78.5% and 92.8%, respectively. The most common metastatic node levels were levelⅡ (76.2%) and levelⅦa (65.1%), followed by levelⅢ (50.4%),Ⅴa(17.5%) andⅣa (11.7%). There was a very low incidence of node skipping (1.0%). Cervical nodal necrosis was observed in 46.4%of patients with positive nodes and extracapsular spread was noted in 74.4% of them. Univariate analysis showed that bilateral nodal involvement, greatest dimension of positive nodes (≥6 cm), central nodal necrosis, T stage and N stage were prognostic factors for disease-free survival and distant metastasis-free survival (P<0.05). Extracapsular spread showed a trend to correlate with poor distant metastasis-free survival (P=0.060). The involvement of lower neck levels (below the caudal border of cricoid cartilage) did not have a signiifcant impact on disease-free survival and distant metastasis-free survival. In multivariate analysis, T stage and greatest dimension of nodes (≥6 cm) were independent prognostic factors for distant metastasis-free survival (P<0.05). T stage, greatest dimension of nodes (≥6 cm) and central nodal necrosis were independent prognostic factors of disease-free survival (P<0.05).Conclusion:This study demonstrates the patterns of lymph node metastasis of nasopharyngeal carcinoma based on 2013 International Consensus Guidelines. Bilateral nodal involvement, greatest dimension of positive nodes and central nodal necrosis had prognostic values on disease-free survival and distant metastasis-free survival. In our study, the involvement of lower neck levels was not proved to be a prognostic factor for disease-free survival and distant metastasis-free survival.
ABSTRACT
Aims: This prospective study was undertaken to evaluate the contrast enhanced computed tomography (CECT) criteria in detecting cervical lymph node metastasis in 50 patients with an oral squamous cell carcinoma (OSQCC). Materials and Methods: A total of 50 patients with OSQCC who underwent clinical assessment, routine CECT scanning of cervical lymph node and radical neck dissection were analyzed. Radiologic criteria for diagnosing nodal metastasis in this imaging study were: A nodal size of 1 cm, the presence of central lucency despite the size of the lymph node and grouping of lymph nodes. These criteria were based on modified American Joint Committee on Cancer Radiological Nodal Staging Guidelines. Statistical Analysis: Chi-square test/Fisher Exact test has been used to find the significant association of findings. Diagnostic statistics viz.: Sensitivity, specificity, positive predictive value (PPV), negative predictive value, and diagnostic accuracy were obtained. The results were considered significant when P value was less than 0.05. Results: On using a nodal size of 1 cm and the presence of central nodal necrosis (CNN) as radiological criteria for nodal metastasis CT scanning staged 23 of the 27 histopathologically positive necks, providing accuracy of 88%, sensitivity of 92%, and specificity of 84% in detection of nodal metastasis. A significant relationship between the incidence of CNN, different nodal densities, and primary tumor differentiation was observed. Conclusions: The nodal size cut-off of 1-1.5 cm had a maximal sensitivity of 90.91% and PPV of 86.96%. Furthermore, observation of nodal densities in the absence of frank CNN on the CT scan may be necessary especially in low grade primary tumor. CT assessment of cervical node metastasis was found acceptable, although adjuncts like ultrasound guided fine needle aspiration may further increase efficacy of CT scan in nodes lesser than 1 cm in size.