Texture Indices of 18F-FDG PET/CT for Differentiating Squamous Cell Carcinoma and Non-Hodgkin’s Lymphoma of the Oropharynx

We assessed the role of 18F-FDG PET/CT texture indices for the differentiation of squamous cell carcinoma (SCC) and non-Hodgkin’s lymphoma (NHL) in the oropharynx. 18F-FDG PET/CT data for 27 patients with SCC and 25 patients with NHL in the oropharynx were investigated. The maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and six texture indices (homogeneity, entropy, short-run emphasis, long-run emphasis, low gray-level zone emphasis [LGZE], and high graylevel zone emphasis [HGZE]) were derived from PET images. PET/CT parameters of the SCC patients were compared with those of the NHL patients. The diagnostic accuracy of the indices for differentiating SCC from NHL was calculated by a receiver operating characteristic curve analysis. 18F-FDG uptake in the oropharynx was observed in all of the patients. The SUVmax, MTV, and TLG did not differ significantly between the SCC and NHL groups, but two of the six texture indices (LGZE [p=0.004] and HGZE [p=0.03]) showed significant differences between the groups. LGZE was the best discriminative index for the differentiation of SCC and NHL (55.6% sensitivity, 88.0% specificity). The LGZE and HGZE texture indices derived from 18F-FDG PET/CT images may be useful in differentiating SCC and NHL in the oropharynx.