PET scan tracer predicts success of cancer ‘vaccine’

Sam Gambhir | Via Stanford University | May 14, 2018

By engineering a special molecule to track certain immune cells in the body, scientists at the Stanford University School of Medicine have invented a litmus test for the effectiveness of a newly devised cancer therapy.

The molecule is a radioactive tracer that latches onto immune cells when they’re activated — the status that immune cells, in particular T cells, assume when they’re poised to kill tumor cells.

“It’s not good enough to just image all T cells; you need to image activated T cells because those are the ones that are going to kill the tumor,” said Sanjiv “Sam” Gambhir, MD, PhD, professor and chair of radiology at Stanford. “The problem that occurs in other approaches, including ones we’ve previously developed, is that they’re sometimes not specific enough. I could image tumor patients who’ve yet to receive an immunotherapy; they’ll sometimes show T cells in their tumors, but those T cells aren’t always activated and killing tumor cells… Continue reading.