[18F-FDG uptake of lymphoma lesions of various histological subtypes]

Malignant lymphoma has high 2-fluorine-18-fluoro-2-deoxy-D-glucose (18F-FDG) uptake. This study was to analyze 18F-FDG uptake of lymphoma lesions of various histological subtypes.

FDG PET/CT images of 102 naive lymphoma patients were analyzed. The maximal standardized uptake value (SUVmax) of every single lesion and the SUVmax of mediastinal blood pool were measured and used to calculate the mean T/MB value (tumor SUVmax /mediastinal SUVmax) of every patient. The mean T/MB value of the patients with the same subtype of lymphoma was calculated. The differences in T/MB value between Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL) patients, between HL and indolent NHL, invasive NHL patients, between B-cell NHL and NK/T-cell NHL patients, and between diffuse large B-cell lymphoma (DLBCL) patients of different stages were analyzed. The expression of Ki-67 in lymph nodes from four patients with relative low T/MB value was detected.

The T/MB values were 4.50+/-1.54 in HL patients and 5.21+/-2.86 in NHL patients (P=0.154). The T/MB value was significantly higher in invasive NHL patients than in HL and indolent NHL patients (P<0.001). The T/MB values were 5.29+/-3.00 in B-cell NHL patients and 4.91+/-2.30 in NK/T-cell NHL patients (P=0.57). There was also no significant difference between DLBCL patients of different stages. The positive rate of Ki-67 was lower in the four patients with relative low T/MB value than in positive control group.

18F-FDG uptake of lymphoma lesions is related to lymphoma invasion, but not related to cell origin and clinical stage. The low 18F-FDG uptake in four patients may be related to low expression of Ki-67.