¹⁸F-FDG uptake by spleen helps rapidly predict the dose level after total body irradiation in a Tibetan minipig model.

Abstract

To investigate whether (18)F- FDG uptake can be applied in dosimetry to facilitate the rapid and accurate evaluation of individual radiation doses after a nuclear accident. Forty-eight Tibetan minipigs were randomised into a control group (n = 3) and treatment groups (n = 45). (18)F-FDG combined positron-emission tomography and computed tomography (PET/CT) were carried out before total body irradiation (TBI) and at 6, 24 and 72 h after receiving TBI doses ranging from 1 to 11 Gy. Spleen tissues and blood samples were also collected for histological examination, apoptosis and blood analysis. Mean standardised uptake values (SUVs) of the spleen showed significant differences between the experimental and the control groups. Spleen SUV at 6 h post-irradiation showed significant correlation with radiation dose; Spearman's correlation coefficient was 0.97 (P < 0.01). Histological observations showed that damage to the splenic lymphocyte became more severe with an increase in the radiation dose. Moreover, apoptosis was one of the major routes of splenic lymphocyte death, which was also confirmed by flow cytometry analysis. In the Tibetan minipig model, radiation doses have a close relationship with the (18)F-FDG uptake of the spleen. This finding suggests that (18)F-FDG PET/CT may be useful for the rapid detection of individual radiation doses.