Researchers conducted a small study to see how a new type of imaging tracer, called [68Ga]Ga-FAPI-04, behaves inside liver cancer tumors. They compared it to a more common tracer, [18F]FDG, in 23 patients with 26 liver cancer lesions. The study looked at where the radioactive signal was strongest within the tumors.
The main finding was that the new FAPI tracer was absorbed much more at the outer edges of the tumors than in their centers. The difference was statistically significant. As the imaging signal threshold increased, the tracer's activity became concentrated at the tumor margins and dropped off sharply toward the center.
No safety issues or side effects from the tracer were reported in this study. The key reason for caution is that this was a small, early study designed to observe a pattern, not to prove a treatment works. The results suggest that treatments targeting the FAP protein might work better on the edges of these tumors, but the low uptake in the center could limit its effectiveness there. Readers should view this as an interesting early observation that helps scientists understand liver cancer biology better, not as a ready-for-use treatment guide.