Good Samaritan Regional Medical Center Radiation Oncology

External beam radiation therapy is the most common type of radiation therapy. A beam of radiation is directed through the skin and surrounding area to destroy the main tumor and any nearby cancer cells. To minimize side effects, the treatments are typically given every day for a number of weeks.

The radiation beam comes from a machine located outside of your body that does not touch your skin or the tumor. Receiving external beam radiation is similar to getting an X-ray. It is a painless, bloodless procedure. The most common type of machine used to deliver external beam radiation therapy is called a linear accelerator. It produces a beam of high-energy X-rays or electrons. Using sophisticated treatment planning software, your radiation oncology treatment team plans the size and shape of the beam, as well as how it is directed at your body, to effectively treat your tumor while sparing the normal tissue surrounding the cancer cells.

Several special types of external beam therapy are used for particular types of cancer, and your radiation oncologist will recommend one of these treatments if they believe it will help you.

For tumors that require particularly precise radiation targeting, intensity modulated radiation therapy (IMRT) is used. This advanced form of external beam radiation is especially valuable in treating tumors that are situated among healthy tissues or critical organs.

IMRT is a specialized form of radiation therapy that allows radiation to be more exactly shaped to fit your tumor. With IMRT, the radiation beam can be broken up into many “beamlets,” and the intensity of each beamlet can be adjusted individually. Using IMRT, it may be possible to further limit the exact amount of radiation that is received by normal tissues that are near the tumor. In some situations, this may also allow a higher dose of radiation to be delivered to the tumor, increasing the chance of being cancer-free.

IMRT allows for a radiation beam to be so accurately sculpted to the tumor shape that it can zoom in on its target with minimal damage to surrounding tissue. The precision targeting also allows physicians to intensify the radiation to the cancerous area.

Tumors usually have an irregular shape. Three-dimensional conformal radiation therapy (3-D-CRT) uses sophisticated computers and computer assisted tomography scans (CT or CAT scans) and/or magnetic resonance imaging scans (MR or MRI scans) to create detailed, three-dimensional representations of the tumor and surrounding organs.

Your radiation oncologist can then shape the radiation beams exactly to the size and shape of your tumor. The tools used to shape the radiation beams are multileaf collimators or blocks. Because the radiation beams are precisely directed, nearby normal tissue receives less radiation exposure.

Deep Inspiration Breath Hold (DIBH) is a technique that can help breast cancer patients, specifically left breast, further protect their heart during radiation therapy.

Using this technique, a patient takes deep breaths during treatment, which expands the lungs and moves the breast away from the heart. This allows for better control, accuracy and timing of radiation treatment to the tumor, minimizing risk to nearby organs.