The main difference between chemotherapy and radiation is that chemo uses one or more medications in the treatment of cancer and radiation uses radio waves for the same purpose. Chemotherapy combines chemicals which kill cancer cells that are delivered intravenously to the patient. Radiation involves the use of radio waves, which also kill cancer. They both may be beneficial at treating different types of cancers, as some respond better to one treatment than the other.
Both chemotherapy and radiation kill cancer cells, often by destroying their deoxyribonucleic acid (DNA). It is also true that neither method can target cancerous cells specifically, so they also kill or damage healthy cells. This can lead to severe side effects like fatigue, compromised immune function, nausea, vomiting, weight loss or gain, and malaise. The correct course of treatment for any given patient may vary, as chemotherapy and radiation are both effective treatments and sometimes a combination of the two will be used.
Although both are used in the treatment of cancer, chemotherapy and radiation differ in the processes used to administer the treatments. Chemotherapy uses chemicals and medications which are often delivered directly into the bloodstream through an intravenous line. These substances kill cells throughout the body and can effectively treat may forms of cancer and certain other diseases. Advances in medical technology may one day allow chemotherapy to target and destroy only cancerous or mutated cells that may eventually form cancer.
Radiation also destroys cells, but instead of using tangible chemicals and medications, it uses high energy radio waves to kill dangerous cells. It also gets rid of many healthy cells. This is one cause of side effects.
Although chemotherapy and radiation are both hard on the body, many patients find radiation treatments to be far more problematic in terms of troubling side effects and symptoms. Additional medications are often given to offset the side effects of both treatments, especially if a patient is having trouble eating or drinking, as this could lead to malnutrition.
Sometimes chemotherapy and radiation are used together to combat aggressive forms of cancer. They can also be combined with other methods of treatment, such as special diets or natural treatments. The overall effectiveness of any cancer treatment will depend on many factors, including what stage the disease is in and the type of cancer. In general, health care providers use the lowest level of treatment possible to prevent potential complications and painful side effects.