Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Computed tomography scan of the chest showing regions of radiation that conform to a tumour (green = 18 Gy, orange = 30 Gy, yellow = 54 Gy, blue = 60 Gy, red = 80 Gy). Multiple beams of radiation converge from a wide range of angles and planes.
