Precision Radiotherapy Center Treatment Information

Cancer doctors usually treat cancer with radiation therapy, surgery or medications including chemotherapy, hormonal therapy and/or biologic therapy, either alone or in combination.

If your cancer can be treated with radiation, you will be referred to a radiation oncologist — a doctor who specializes in treating patients with radiation therapy. Your radiation oncologist will work with your primary doctor and other cancer specialists, such as surgeons and medical oncologists, to oversee your care. He or she will discuss the details of your cancer with you, the role of radiation therapy in your overall treatment plan and what to expect from your treatment.


How Does Radiation Therapy Work?

Radiation therapy, or radiotherapy, is the use of various forms of radiation to safely and effectively treat cancer and other diseases. Radiation oncologists may use radiation to cure cancer, to control the growth of the cancer or to relieve symptoms, such as pain.

Radiation therapy works by damaging cells. Normal cells are able to repair themselves, whereas cancer cells cannot. New techniques also allow doctors to better target the radiation to protect healthy cells.

Sometimes radiation therapy is the only treatment a patient needs. At other times, it is only one part of a patient’s treatment. For example, prostate and larynx cancer are often treated with radiotherapy alone, while a woman with breast cancer may be treated with surgery, radiation therapy and chemotherapy.

Radiation may also be used to make your primary treatment more effective. For example, you can be treated with radiation therapy before surgery to help shrink the cancer and allow less extensive surgery than would otherwise be needed; or you may be treated with radiation after surgery to destroy small amounts of cancer that may have been left behind.

A radiation oncologist may choose to use radiation therapy in a number of different ways. Sometimes the goal is to cure the cancer. In this case, radiation therapy may be used to:

  • Destroy tumors that have not spread to other parts of your body.
  • Reduce the risk that cancer will return after you undergo surgery or chemotherapy by killing small amounts of cancer that might remain.

Sometimes, the overall goal is to slow down the cancer as much as possible. In other cases, the goal is to reduce the symptoms caused by growing tumors and to improve your quality of life. When radiation therapy is administered for this purpose, it is called palliative care or palliation. In this instance, radiation may be used to:

  • Shrink tumors that are interfering with your quality of life, such as a lung tumor that is causing shortness of breath.
  • Relieve pain by reducing the size of your tumor.

It is important for you to discuss the goal of your treatment with your radiation oncologist.

Treatment Methods

External Beam Radiation Therapy Treatments

The goal of radiation therapy is to get enough radiation into the body to kill the cancer cells while preventing damage to healthy tissue. There are several ways to do this. Depending on the location, size and type of cancer, you may receive one or a combination of techniques. Your Sam Houston Cancer Center treatment team will help you to decide which treatments are best for you.

Radiation therapy can be delivered in two ways, externally and internally. During external beam radiation therapy, the radiation oncology team uses a machine to direct high-energy X-rays at the cancer. Internal radiation therapy, or brachytherapy, involves placing radioactive sources (for example, radioactive seeds) inside your body.

External Beam Radiation Therapy

During external beam radiation therapy, a beam of radiation is directed through the skin to the cancer and the immediate surrounding area in order to destroy the main tumor and any nearby cancer cells. To minimize side effects, the treatments are typically given five days a week, Monday through Friday, for a number of weeks. This allows doctors to get enough radiation into the body to kill the cancer while giving healthy cells time each day to recover.

The radiation beam is usually generated by a machine called a linear accelerator. The linear accelerator, or linac, is capable of producing high-energy X-rays and electrons for the treatment of your cancer. Using high-tech treatment planning software, your treatment team controls 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 surrounding normal tissue.

Several special types of external beam therapy are discussed in the next sections. These are used for specific types of cancer, and your radiation oncologist will recommend one of these treatments if he or she believes it will help you.