Fig. 3.

Localization of pheochromocytoma lesions by [¹⁸F]-DA or [¹⁸F]-DOPA PET in representative animals after i.v. (Panels 1–E) and s.c. (Panel G) injections of MPC cells. Upper panels, A and B, show microCT coronal images using Fenestra contrast agent with respiratory gating in a representative animal after i.v. injection of MPC cells. The animal was imaged on days 38 through 47 after i.v. injection of MPC cells, where panels C and E show rapid growth of liver lesions visible using [¹⁸F]-DA PET over a 7-day time period. [¹⁸F]-DOPA PET visualization of the same animal over consequent days is shown in panels D and F. Images were acquired at 60–70 min after injection of radiopharmaceuticals. The localization of a large s.c. tumor depicted by transverse and coronal images after s.c. injection of [¹⁸F]-DA and [¹⁸F]-DOPA into another representative animal is shown in Panel G. [¹⁸F]-DA PET imaging reveals very low accumulation of the radiopharmaceutical in the tumor (0.35 SUV_max), almost at the level of nontarget tissue such as muscle (0.31 SUV_max). In contrast, the uptake of [¹⁸F]-DOPA by the same tumor was much higher (2 SUV_max). Circles identify the tumor on both transverse and coronal images and arrows points to the liver.