How Radiation Works

Expert Quote

“Cancer cell growth is unwieldy and uncontrolled—these cells just don't have their act together like normal cells do. When normal cells are damaged by radiation, they are like a big city with a fire and police department and trained emergency squads to come and 'put out the fire.' Damaged cancer cells are more like a disorganized mob with a bucket. ”

Marisa Weiss M.D.

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Light is a form of radiation energy that we can see. Radiation therapy includes other forms of radiation that have higher energy levels and are invisible to the human eye.

Radiation therapy's high-energy beams are focused on the area that needs to be treated. This might include the breast area, lymph nodes, or another part of the body. Over time, this focused radiation damages cells that are in the path of its beam—normal cells as well as cancer cells. But radiation affects cancer cells more than normal cells. Cancer cells are very busy growing and making new cells—two activities that are very vulnerable to radiation damage. And because cancer cells are less organized than healthy cells, it's harder for them to repair the damage and recover. So cancer cells are more easily destroyed by radiation, while healthy, normal cells are better able to repair themselves and survive.

There are two ways to give radiation therapy: externally and internally.