ĐẶC ĐIỂM HÌNH ẢNH FDG PET/CT CỦA U LYMPHO KHÔNG HODGKIN TẾ BÀO T

SUMMARY

Objective: T-cell non-Hodgkin lymphomas (NHL) is a group of uncommon lymphomas, accounting for about 12% of all cases of non-Hodgkin lymphoma. The purpose of this study is to investigate the sites and metabolic activity of lesions in T-cell NHL on FDG PET/CT images, and to determine the correlation between metabolic activity and Ki67.

Patients and methods: A retrospective study of patients with T-cell NHL who underwent FDG PET/CT examination for initial disease staging from 2009 to 2019.

Results: A total of 62 patients (37 men and 25 women) with mean age of 44.8 were included in this study. There were 30/62 patients with histopathological subtypes, in which the highest frequency was peripheral T-cell lymphoma, not otherwise specified, and extranodal NK/T-cell lymphoma, nasal type with 8 cases (26.7%) each. PET/CT images showed the frequency of lesions in the lymph node regions in descending order of neck (67.7%), axillary (41.9%), mediastinum (40.3%), abdomen (40.3), inguinal area (37.1%). There were 32 extranodal sites/organs involved in T-cell NHL, most commonly in the spleen (27.4%), nasal cavity (24.2%), bone marrow (22.6%), nasopharynx (21%) with a frequency greater than 20%. The mean SUVmax of lymph nodes in descending order was 9.9 (in the abdominal lymph nodes), 7.7 (in the cervical lymph nodes), 7.7 (in the axillary lymph nodes), 6.2 (in the mediastinal lymph nodes), 5.9 (in the inguinal lymph nodes). The majority (81%) of lesions in extranodal sites/organs had a mean SUVmax ≥5. Sites/organs with high frequency of lesions having the highest mean SUVmax were skeletal muscle (17.3), nasal cavity (12.3), skin/subcutaneous tissue (11.7), nasopharynx (10.2), lung (6.9), pleura (6.8), bone marrow (5.3), liver (5.0) and spleen (5.0). Analysis of the linear correlation between SUVmax of the lesion at the biopsy site and the percentage of Ki67 was performed in 24 patients, and the results showed no correlation (r=0.03).

Conclusion: In patients with T-cell NHL, FDG PET/CT is useful for detecting lesions in many sites/organs in the body. The metabolic activity of the lesions was high, but there was no correlation between SUVmax and Ki67.

Keywords: T-cell non-Hodgkin lymphoma, FDG PET/CT, Ki67.