Reportage on PET imaging at the Antoine-Lacassagne Cancer centre in Nice, France. Positron Emission Tomography, or PET scan, is used in diagnosing and monitoring patients with cancer. This method enables tumours to be detected using a radioactive tracer, which accumulates heavily in cells that present a pathological hypermetabolism. The scintigraphy doctor interprets the results. Imaging from the whole body are looked at. No irregularity is visible on the screen.