Professional
Technical
IVT
OAR
Also written as: OAR — Organs at Risk
Critical normal structures that must be protected from excessive radiation exposure during treatment planning.
Full Definition
Organs at Risk are normal anatomical structures near the treatment target that are particularly sensitive to radiation and must be considered during treatment planning. These may include the spinal cord, brainstem, heart, lungs, kidneys, and other critical organs. Dose constraints for OARs are established to minimize the risk of radiation-induced complications.
Usage
Usage note: Plural form is OARs, not OAR's.
In Context
- "The treatment plan violated OAR constraints for the left parotid gland." — Plan evaluation report
- "Careful OAR delineation is essential for safe dose escalation." — Planning protocol
Also known as
organs at risk
critical structures
dose-limiting organs
Contrasted with
target volume
GTV
Don't confuse with
PRV
CTV