Clinical value of 18F-FDG PET/CT in patients with extranodal nasal type natural killer/T-cell lymphoma / 中华核医学与分子影像杂志

ABSTRACT

Objective To analyze the image characteristics and clinical value of 18F-FDG PET/CT in patients with extranodal nasal type natural killer/T-cell lymphoma (ENKTL).Methods From January 2012 to March 2016,20 ENKTL patients (12 males,8 females;median age 53 years) who underwent whole-body 18F-FDG PET/CT were enrolled in this retrospective study.Eleven patients were newly diagnosed,and 9 were previously treated.Clinical data were collected for histopathology and bone marrow biopsy,laboratory results,PET/CT and radiological findings such as CT or MRI.The final diagnosis was based on histopathology and immunohistochemistry.Mann-Whitney u test was used to compare the SUVmax of newly diagnosed patients and patients with recurrence or disease progression after therapy.Spearman correlation analysis was used to explore the relation between diameter of tumor-invaded lymph nodes and SUVmax.Results ENKTL could be found in all parts of the body,but more frequently in the nasal cavity,nasopharynx and skin.All lesions showed high uptake of FDG on PET/CT.The SUVmax of newly diagnosed patients was significantly higher than that of patients (n=7) with recurrence or disease progression6.5(4.3,10.4) vs 5.4(3.4,8.9);u=6 853.500,z=-2.039,P＜0.05).The diameter of tumor-invaded lymph nodes showed weakly positive correlation with SUVmax(rs =0.290,P＜0.01),suggesting that invasion of ENKTL might not be accurately evaluated by the size of lymph nodes.The staging by PET/CT was concordant with clinical final staging in 11 newly diagnosed patients,while the staging by CT or MRI was only correct in 6 patients.Conclusions PET/CT is superior to conventional imaging modalities in diagnosis and staging for patients with ENKTL.Since some lesions might be found in the limbs,limbs should be included in the scan field.