The Comparison of Nodal Stage Determined by Magnetic Resonance Imaging and Clinical Palpation for Nasopharyngeal Carcinoma Patients with Bulky Lymph Node Metastasis

Purpose: This study is to find out whether maximal lymph node size determined by magnetic resonance imaging (MRI) correlates with prognosis better than that determined by clinical palpation for patients with nasopharyngeal carcinoma (NPC) and bulky cervical lymph node metastasis. Material and Methods: All eligible NPC patients should have cervical lymph node size 6 cm or greater by clinical palpation and use MRI as primary imaging modality. Patients with N3b and distant metastases were excluded from this study. From 1992 to 2005, a total of 47 patients were included. Their MRI nodal stage was determined at weekly multidisciplinary team conference with a consensus. Patients received concurrent chemoradiotherapy with or without adjuvant chemotherapy according to hospital guideline. We compared the survival and failure patterns of MRI N1-2 and MRI N3a patients. Results: Twenty-two patients were assigned MRI N3a and 25 MRI N1 or N2. With a median follow up of 64 months, the 5-year disease-free survival rate for MRI N3a group (53%) was lower than MRI N1-2 group (65%) but not statistically significant (p=0.56). The 5-year overall survival and metastasis-free survival of MRI N3a vs MRI N1-2 patients were 78% vs. 77% (p= 0.5) and 70% vs. 65% (p= 0.9), respectively. The failure pattern was similar. Conclusion: NPC patients with clinical bulky cervical lymph node metastasis have relatively poor survival regardless of MRI N-stage. We recommend that if cervical lymph nodes are confluent together, their sizes determined by MRI should not be measured separately. These patients are best to be staged as N3a disease.