How Does Radiation Therapy Work?

When an individual is diagnosed with cancer, it is appropriate for him or her to discuss possible cancer treatment options as there are a variety of options to consider. There are two aggressive treatments that are commonly used today in the fight against cancer, those are external beam radiation therapy, or EBRT and intensity modulated radiation therapy or IMRT.

It is widely known that radiation is a relatively effective treatment that emits a high dose of radiation within the body to kill specific cancer cells while working to preserve the nearby healthy cells. It is possible to use one or both radiation treatments and this is determined on the location, size, and type of the tumor.



The purpose of EBRT is to destroy the tumor and cancer cells nearby while preserving healthy tissue as much as possible. This medical procedure is likened to receiving an x-ray as it works by emitting high energy x-rays or electrons. This painless and bloodless procedure involves a machine delivering a beam of radiation to the tumor and surrounding area.

The most common machine used to administer this type of radiation is a linear accelerator, also known as a linac. The size and shape of the beam is determined by the radiation oncologist, in addition to how it is directed at the patient's body, in order to treat the tumor effectively without damaging nearby normal tissue.

IMRT administers high doses of radiation via a highly targeted beam directly to the cancer cells. It is more precise than traditional radiation therapy, and the administering equipment can be rotated in such a way that the beams are emitted at certain angles to effectively treat the tumor. Therefore, by delivering higher doses of radiation directly to the cancer cells at the proper angle, it is more likely that the nearby healthy tissue can be preserved.

Higher doses of radiation have been associated with the reduction of complication rates and improved tumor control, clinical studies have found. Patients that had tumors near vital organs or structures were often considered untreatable. IMRT can now be used for these types of tumors since the beam is highly targeted.

However, because these specific tumors need targeting with complete accuracy, computer images are now conducted for the purpose of planning and delivering the radiation so that it resembles the tumor shape. It is up to the patient's health care provider to determine the radiation dosage based on the tumor size, shape, and location.

Both EBRT and IMRT have been proven to be successful treatments in the fight against all types of cancer, including prostate cancer. Cancer patients receiving EBRT, IMRT, or both, will undergo radiation therapy every day for an undetermined amount of weeks, usually seven to ten, in order to minimize side effects.