Preliminary discussion on the value of ¹⁸F-FDG PET/CT in the diagnosis and early staging of non-mycosis fungoides/Sézary's syndrome cutaneous malignant lymphomas

Highlights: • We discussed the value of PET/CT in the diagnosis and early staging of non-MF/SS CML. • We calculated the sensitivity of CT and PET/CT in the diagnosis of primary skin lesions. • We calculated the value of CT and PET/CT in the diagnosis of LNs and other organs. - Abstract: Objective: To discuss the value of ¹⁸F-fluorodeoxyglucose-positron emission tomography (¹⁸F-PET/CT) scans in the diagnosis and early staging of non-mycosis fungoides/Sézary's syndrome cutaneous malignant lymphomas (non-MF/SS CML). Materials and methods: A total of 18 cases with non-MF/SS CML, confirmed by pathology or on clinical grounds, were analyzed in this study. The sensitivity of CT and PET/CT scans in the diagnosis of primary skin lesions, as well as the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CT and PET/CT scans in the diagnosis of lymph nodes (LNs) and other organs (except skin and LNs) were calculated. Results: The diagnostic sensitivity of CT and PET/CT scans in the diagnosis of primary skin lesions was 82.4% (14/17) and 100% (17/17), respectively. The diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CT and PET/CT scans in the diagnosis of LN lesions were 55.6% (5/9), 88.9% (8/9), 72.2% (13/18), 83.3% (5/6), 66.7% (8/12), and 88.9% (8/9), 100% (9/9), 94.4% (17/18), 100% (8/8), 90.0% (9/10), respectively. The diagnostic value of the CT and PET/CT scans in the diagnosis of involvement of other organs, were 40.4% (2/5), 100% (13/13), 83.3 (15/18), 100% (2/2), 81.3% (13/16) and 80.6% (4/5), 100% (13/13), 94.4% (17/18), 100% (3/3), 92.9% (13/14), respectively. Conclusions: ¹⁸F-FDG PET/CT has high value in the diagnosis and early staging of non-MF/SS CMLs