Two main types of radiation therapy are used for lung cancer:
- External radiation, which is directed at your lung cancer from outside your body
- Internal radiation, or brachytherapy, which uses small radioactive agents placed inside your body near the cancer
Getting Radiation Therapy for Lung Cancer
Treatment with radiation will depend on the size and location of your cancer, the type and stage of your cancer, your general health, and any other treatments you are getting.
Radiation therapy may be used alone or with other lung cancer treatments. It may be given before surgery along with chemotherapy to shrink a tumor so it’s easier to remove, or it may be used after surgery to destroy any remaining cancer cells and reduce the chances that the cancer will return. Radiation therapy may be used as the main treatment for tumors that cannot be removed because of their size or location or in people who are not healthy enough to have surgery. Treatment with radiation may also be used to relieve symptoms of advanced lung cancer, such as pain, bleeding, or trouble swallowing.
Types of Radiation Therapy
Doctors may choose from several types of radiation therapy to treat lung cancer.
External Beam Radiation Therapy
External beam radiation therapy (EBRT) precisely aims radiation beams from outside your body at your cancer. Before you begin treatment, careful measurements are taken to determine the correct dose and target of the radiation. Each patient’s treatment is individualized. EBRT is typically given five days a week for up to eight weeks, using a machine that looks much like a regular X-ray machine. The procedure is not painful. While it may take 30 minutes or so to set up the equipment and get you in position, each treatment lasts only minutes.
Three-Dimensional Conformal Radiation Therapy
Three-dimensional conformal radiation therapy (3D-CRT), a type of EBRT, uses computers to map the location of the cancer in four dimensions. Radiation beams are shaped (conformed) to match the shape of the cancer and are aimed at the cancer from several directions. Using 3D-CRT to more precisely aim the radiation, it may be possible to reduce the radiation damage to normal tissue and increase radiation to the tumor.
Intensity Modulated Radiation Therapy
Intensity modulated radiation therapy (IMRT), a form of 3D-CRT, uses a computer-driven machine to move around the patient to deliver radiation. In addition to shaping the beams and aiming them at the tumor from several angles, the intensity of the beams can be adjusted to lessen the dose that reaches sensitive normal tissue. This technique may be used if tumors are near important structures, such as the spinal cord.
Stereotactic Body Radiotherapy
Stereotactic body radiotherapy (SBRT), also known as stereotactic ablative radiotherapy, is a type of EBRT that may be used when surgery isn’t an option or based on patient preference for people with very small, or very early stage, lung cancers. SBRT aims many beams of high-dose radiation from different angles. To target the radiation beams precisely, a specially designed body frame, which reduces movement, is used for each treatment. Typically SBRT is given in three to five sessions, and it may be repeated if necessary.Another type of stereotactic radiation therapy, called stereotactic radiosurgery, may be used instead of surgery for a tumor that has spread to the brain.
Brachytherapy is typically used to shrink tumors and to relieve symptoms. In some cases it may be part of a larger treatment regimen intended to cure the cancer.
Your doctor places radioactive agents directly into the cancer or into the airway next to the cancer using a bronchoscope (a long, narrow tube inserted through the nose or mouth) or surgically. In brachytherapy, the radiation typically travels a short distance from the source, which limits exposure to healthy tissues.
With high-dose rate brachytherapy, a powerful radioactive source is used, and it is removed after only a few minutes. Sometimes low doses of radiation are delivered by a mesh sewn into the lung. The mesh is left in place permanently, and the radiation gets weaker over several weeks. Special precautions may be needed to protect people around you from the radiation given off by the implant.
Normal cells that are near your cancer may be affected by radiation, which can lead to side effects. The side effects vary greatly from person to person and depend on the type and dose of the radiation and the area of the body being treated. Your treatment team can tell you about the side effects that are most common with your treatment.
Let your team know about any side effects you experience. Your doctor may give you medicines to prevent or relieve side effects. For general advice, see the symptom management section.
The time it takes to get over some side effects and regain energy depends on many factors, including your overall health and your treatment. Many side effects improve or go away after treatment is finished because your healthy cells recover over time.