Figure 2.

¹⁸F-NOTA-FAPI PET/CT and pathologic evaluations of rat lung tissues with different radiation doses. (A) Micro-CT imaging of FAPI uptake in irradiated rat lung tissue. The black dotted line separates the uptake of tracer in the lung from that in the heart, and the white arrow indicates the presence of RILD in the lung tissue after radiation. Rats in the 40 Gy and 60 Gy groups showed no RIP and began to show RILF on days 42 and 35 after radiation, respectively. In contrast, rats in 90 Gy group showed ¹⁸F-NOTA-FAPI uptake in areas of RIP on day 7, with reappearance of tracer uptake in the irradiated area on day 28 after radiation. (B) Representative micrographs of HE-stained lung sections from the 40 Gy, 60 Gy, and 90 Gy groups at days 42, 35, and 28, respectively, showed that the radiation damage was confined to a small area.