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.
GTV, gross tumor volume (yellow); CTV, clinical target volume (red); PTV, planning target volume (blue); TV, treated volume (green); IV, irradiation volume (purple); OAR, organs at risk. In many cases, right from the planning stage, organs at risk, which is a normal tissue, are unavoidably included in the irradiation volume for cancer treatment.
