Efficacy of fine-needle aspiration in diagnosing cervical nodal metastasis from nasopharyngeal carcinoma after radiotherapy

Objectives/hypothesis: Our purpose was to study the effect of previous radiotherapy (RT) on the efficacy of fine-needle aspiration (FNA) in diagnosing cervical nodal metastasis in nasopharyngeal carcinoma (NPC).

Study design: Case-control study.

Methods: The diagnostic efficacy of FNA in a group of patients with residual or recurrent cervical lymphadenopathy after previous RT for NPC was compared with a cohort of patients with primary NPC before RT during the same period.

Results: Between 2008 and 2010, 50 patients were included for each group in the study. The specificity (100% vs. 88%, P = .12) and positive predictive value (100% vs. 89%, P = .12) was comparable in the two groups. However, the sensitivity (82% vs. 40%, P = .04), negative predictive value (NPV; 74% vs. 36%, P = .03), and accuracy (88% vs. 54%, P = .05) were significantly worse after previous RT. Previous RT was the only factor that was significantly associated with worse diagnostic efficacy (P = .001). When used together with plasma Epstein-Barr virus (pEBV)-DNA level and magnetic resonance imaging (MRI) findings (triple assessment), the diagnostic efficacy was significantly improved, especially regarding sensitivity (40% vs. 98%, P = .01), NPV (36% vs. 96%, P = .02), and accuracy (54% vs. 97%, P = .03).

Conclusions: Diagnostic efficacy of FNA for residual or recurrent cervical lymph node metastasis in NPC is significantly reduced after previous RT. To ensure that the proper diagnosis is made early, triple assessment using FNA, pEBV-DNA, and MRI should be adopted in this scenario.