Researchers tested a new type of PET scan that aims to show where immune cells called CD8 cells are located inside tumors. The study involved 49 patients with various solid tumors who were receiving immunotherapy. They compared the scan results to cell counts from small tissue samples taken from the tumors.
The main finding was a modest link between the scan's signal and the number of CD8 cells found in the biopsies. In a smaller group of patients with kidney cancer, this link was stronger. The study reported that having the scan twice was safe for patients.
It's important to be careful with these results. The link was not perfect, partly because a small biopsy cannot capture all the immune cells spread throughout a whole tumor. This was a Phase II study, which means it's still early research. The study did not test whether this scan can predict if a patient will respond to their immunotherapy treatment. More research is needed to see if this imaging tool could be useful for doctors in the future.