Radiation Therapy Education

Radiation Therapy Education

Why are cancer cells destroyed when they are exposed to radiation therapy? Education on this subject will help you understand the whole radiation therapy process.

If you haven't already read the "What Is Cancer?" and "What Causes Cancer?" sections of Cancer 101, then you might want to check out those first - those two sections give more details on how cells play a part in the whole cancer process.

External Radiation Therapy Education
When radiation beams strike cells (healthy and cancerous), the beam either

forces atoms out of the DNA chain of the cell, or

causes the formation of "free radicals", which then damage the DNA chain of the cell.

When pieces of a cell's DNA chain are missing or damaged, cells begin the task of repairing themselves. Cancer cells have a difficult time repairing themselves because they are all very, very similar to one another - in other words, they don't take the time to differentiate themselves during the cell division process. Cells that are differentiated have a better chance at surviving damage and being able to repair themselves.

When a cell is not able to repair the damage to its DNA chain, it produces damaged daughter cells in the cell division process. Damaged cells reproduce more slowly and eventually die.

Normal, healthy cells are better able to repair themselves after being exposed to radiation beams because they are typically more differentiated than cancer cells. Since they are able to repair their DNA chains prior to the cell division process, their daughter cells also turn out healthy.

The idea behind radiation therapy is to damage more cancer cells than healthy cells, thereby killing off cancer cells or at least stopping the growth of cancer tumors.

Internal Radiation Therapy Education
Internal radiation therapy works in a similar way to the external radiation beams described above - the difference is that the radiation that is emitted from the seeds, wire, or tubing placed in your body is more closely focused on the cancer tumor itself, which cuts down on the number of healthy cells damaged in the radiation therapy process.

Radiation Therapy Side Effects
Radiation therapy side effects result from damage to healthy cells. For example, the skin on your body in the path of the radiation beams may become dry because the beams inadvertently damage some of your skin cells - but since they are healthy cells, they are better able to repair themselves and eventually your skin will regain some of its elasticity.

Another radiation therapy side effect (if the radiation beams are directed at your head) is loss of hair. The reason why hair loss due to radiation may be permanent is because hair cells behave like cancer cells - they are not very differentiated and reproduce, or divide, very quickly. (Think about how quickly your hair grows!) As such, hair cells are not able to repair the damage done to their DNA chains prior to dividing. As a result, the hair cells can't reproduce undamaged daughter cells, and they die.

Radiation therapy education goes a long way towards understanding how radiation fights cancer in your body and why you may experience radiation therapy side effects.

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