Whole-body (18)F-FDG PET/CT for M staging in the patient with newly diagnosed nasopharyngeal carcinoma: Who needs?

Whole-body (18)F-FDG PET/CT for M staging in the patient with newly diagnosed nasopharyngeal carcinoma: Who needs?

Eur J Radiol. 2017 Apr;89:200-207

Authors: Ren YY, Li YC, Wu HB, Wang QS, Han YJ, Zhou WL, Li HS

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-body (18)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≥9000copies/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 ≥9000copies/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 (χ(2)=29.896, P=0.000), and needed a whole-body (18)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.

PMID: 28267540 [PubMed - in process]

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