Comparative [18F]FDG and [18F]DPA714 PET imaging and time-dependent changes of brown adipose tissue in tumor-bearing mice

Figures & data

Figure 1. Static whole-body microPET imaging of CT26 tumour-bearing mice with [¹⁸F]FDG

The representative images (at transaxial, sagittal and coronal sections) showing the radioactive uptake of [¹⁸F]FDG in whole body of the CT26 tumour-bearing mice. The [¹⁸F]FDG uptake in the BAT of the scapular region in this tumour model was distinguished between animals. Among the 16 mice, 7 had significant BAT uptake in the scapular region (as shown in the left, ‘higher uptake’, %ID/g-mean = 15.84 ± 9.35, n = 7), while the other 9 animals had no obvious BAT [¹⁸F]FDG uptake in the scapular region (shown in the right, ‘lower uptake’, %ID/g-mean = 2.99 ± 1.31, n = 9). The PET imaging also showed obvious [¹⁸F]FDG uptake in the heart, liver, brain and tumour in the CT26 tumour models. SUV, Standard Uptake Value of the radioactivity.

Figure 2. Characteristics of biodistribution of [¹⁸F]FDG and [¹⁸F]DPA714 in the CT26 tumour model

The biodistribution of [¹⁸F]DPA714 in the CT26 tumour-bearing mice was significantly different from that of [¹⁸F]FDG. The BAT uptake of [¹⁸F]DPA714 in the scapular region was significantly higher than that of [¹⁸F]FDG (p < 0.01). [¹⁸F]DPA714 uptake in the scapular region was similar and consistent between all the scanned tumour-bearing mice. n = 6 mice for each group. Delineated ROIs for the scapular BAT regions are shown in the images.

Figure 3. Biodistribution and BAT uptake of [¹⁸F]DPA714 in different tumour models

A549 (n = 6 mice), CT26 (n = 6) and LLC (n = 5) tumour models were used for the study of the characteristics of [¹⁸F]DPA714 as an imaging tracer for BAT monitoring. Average tumour volume was (500 ± 100) mm³ for each group at microPET scanning. Radioactive uptake of [¹⁸F]DPA714 in the scapular region of the different tumour models was all relatively high and consistent with each other group.

Figure 4. Time-longitudinal microPET imaging with [18F]DPA714 in CT26 xenograft mice

PET scans were performed at day 7 and day 26 following tumour cell injection with radioactive tracer [¹⁸F]DPA714. (a) The radioactive uptake of [¹⁸F]DPA714 in the scapular BAT region was the highest among all the organs. (b) The %ID/g-mean and (c) %ID/g-max of the radioactive uptakes in the scapular region at day 26 were both significantly higher than those at day 7 (p = 0.041; p = 0.026; n = 6 mice for each time point).