Table 3.

Recommendations for diagnostic and staging evaluation

Diagnostic and Staging	Level of evidence
Definitive diagnosis is made by endoscopic-guided biopsy of the primary nasopharyngeal tumour; diagnostic neck biopsy and/or neck nodal dissection should be avoided	[II, A]
Determination of EBV on the histological specimen by ISH is indicated	[III, B]
Analysis of EBV DNA in plasma is useful for screening at-risk populations for nasopharyngeal carcinoma. It can detect the cancer at an early stage with a superior treatment outcome compared with the unscreened population	[III, A]
For the initial diagnostic evaluation of nasopharyngeal carcinoma, we suggest endoscopically guided biopsy of the primary tumor and magnetic resonance imaging (MRI) of the nasopharynx, skull base, and neck to assess locoregional disease extent	[III, B]
For patients with advanced nodal stage (N3) or clinical or biochemical evidence of distant metastases, we offer additional imaging with positron emission tomography (PET) or integrated PET/computed tomography (CT) imaging if available. Otherwise, bone scan and CT of the chest and abdomen may be obtained	[III, B]
We suggest obtaining pretreatment plasma EBV DNA levels for their prognostic significance. There is emerging evidence supporting serial measurement of plasma EBV DNA levels to assess treatment response or monitor for recurrence	[III, B]