Whole-body18 F-FDG PET/CT for M staging in the patient with newly diagnosed nasopharyngeal carcinoma: Who needs?

• Published in: European journal of radiology Vol. 89; pp. 200 - 207
• Main Authors: Ren, Yun-yan, Li, You-cai, Wu, Hu-bing, Wang, Quan-shi, Han, Yan-jiang, Zhou, Wen-lan, Li, Hong-sheng
• Format: Journal Article
• Language: English
• Published: 2017
• Subjects: Radiology; Nasopharyngeal carcinoma; 18F-FDG PET/CT; Whole-body scan; Staging; Head and neck cancer; EBV DNA level
• ISSN: 0720-048X
• DOI: 10.1016/j.ejrad.2017.02.002

Abstract Objective Although whole-body fluorine-18 fluorodeoxyglucose (18 F-FDG) positron emission tomography (PET)/computed tomography (CT) (18 F-FDG PET/CT) is commonly used for M staging of newly diagnosed nasopharyngeal carcinoma (NPC), some patients may not benefit from this procedure. The present study investigated which patients require this modality for M staging. Methods Whole-body18 F FDG PET/CT results and clinical data were collected for 264 patients with newly diagnosed NPC. The relationships between distant metastasis and age, gender, pathological type, lesion size, SUVmax-T, T staging, N staging, SUVmax-N and Epstein-Barr virus (EBV) quantity were retrospectively analysed to identify factors associated with increased risk. Results Of the 264 patients, only 37 (14.0%) were diagnosed with distant metastasis. Using multiple logistic regression analysis, EBV-positivity (OR = 13.1; 95% CI:1.61,106.80), N staging (OR = 3.05; 95% CI:1.41,6.63) and T staging (OR = 2.16; 95% CI:1.10, 4.24) were significantly related to distant metastasis (all P < 0.05 ). EBV DNA levels ≥ 9000 copies/ml, N3 stage and T4 stage were identified as high risk factors. A low risk of distant metastasis was found in patients with 0–1 risk factors and in those with 2 specific risk factors, T3/T4 and N2/N3 staging. Patients with EBV DNA levels ≥9000 copies/ml and N3 or T4 staging and those with 3 risk factors had a medium or high risk, with a much higher incidence of distant metastasis (χ2 = 29.896, P = 0.000), and needed a whole-body18 F FDG PET/CT for M staging. Conclusions Due to the low incidence of distant metastasis, only patients with medium or high risk need to undergo a whole-body scan.