1. Health
You can opt-out at any time. Please refer to our privacy policy for contact information.

Linear Accelerator (LINAC) Definition


Updated March 31, 2010

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

External Beam Radiation Machine

External Beam Radiation Machine

Photo © National Cancer Institute
Definition: A linear accelerator (LINAC) is a machine that generates energy for external beam radiation treatments for cancer.

The linear accelerator causes electrons to speed up as they pass through a wave-guide and shoots the particles at a heavy metal target, forming high-energy X-rays. Lines of accelerated x-ray radiation are shaped to target a tumor or surgery site, limiting radiation exposure to healthy tissue while killing cancer cells.

Also Known As: linac, mega-voltage linear accelerator, MeV linear accelerator
A linear accelerator is used during whole breast radiation, accelerated partial breast radiation, and Intensity-Modulated Radiation Therapy (IMRT). A portable linear accelerator can be brought into the operating room for intraoperative radiation therapy (IORT) during a lumpectomy for breast cancer.
  1. About.com
  2. Health
  3. Breast Cancer

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.