Utility of PET/CT in the Diagnosis and Staging of Extranodal Natural Killer/T-Cell Lymphoma

The role of 18F-fuorodexoyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) in the staging of Hodgkin lymphoma (HL) and aggressive B-cell non-Hodgkin lymphomas (NHL) has been demonstrated extensively. Nevertheless, the role of PET/CT in the diagnosis, staging, prognosis, and treatment evaluation of natural killer (NK)/T-cell lymphoma remains indeterminate. To systematically review and meta-analyze the publications on the value of 18F-FDG-PET/CT in the diagnosis and staging of NK/T-cell lymphoma. Pubmed, Embase, Cochrane Library, and some other database were searched for initial studies (last updated on May 8th, 2014).The eligibility criteria were studies assessing the usefulness of PET/CT in the staging of NK/T-cell lymphoma, patients were diagnosed as NK/T-cell lymphoma through pathology, or clinical and imaging follow-up. Sensitivities and specificities of 18F-FDG-PET/CT in individual studies were assessed. The summary receiver operating characteristic curve (sROC) and the area under the curve (AUC) were calculated. The "Meta-Disc 1.4" software was used for data analysis. Eight studies, with a total of 135 NK/T-cell lymphoma patients, were included in this meta-analysis. In terms of the 6 studies with patient based data, the pooled sensitivity and specificity of PET/CT in the diagnosis of NK/T-cell lymphoma were 0.95 (95% CI: 0.89-0.98) and 0.40 (95% CI: 0.09-0.78), respectively. For lesion-based analysis, with 1546 lesions included, the pooled sensitivity and specificity of PET/CT in the staging of NK/T-cell lymphoma were 0.98 (95% CI: 0.96-0.99) and 0.99 (95% CI: 0.99-1.00), respectively. For the patient based data, the AUC and Q index were 0.8537 and 0.7847, respectively. For lesion based data, the AUC and Q index were 0.9959 and 0.9755, respectively. The results of this current meta-analysis indicated that PET/CT could be used as a valuable diagnostic and staging tool for NK/T-cell lymphoma.