Radiation Therapy

Radiation therapy is a lung cancer treatment that uses high doses of radiation to kill cancer cells. Radiation therapy may be given externally, using a machine that is guided to direct radiation beams directly to the tumor site, or it may be given internally, using radioactive substances that are placed inside the body at the tumor site. One type of internal radiation therapy is known as brachytherapy. Radiation therapy is managed and directed by a radiation oncologist, a specialist physician that determines the best angles and total radiation dose to be given to the patient.1-3

Radiation therapy may be used:

  • When the lung tumor can’t be removed by surgery due to its size or location
  • When the patient isn’t healthy enough for surgery, or if the patient doesn’t want surgery
  • Prior to surgery to shrink the tumor to make it easier to remove
  • Following surgery to kill any remaining cancerous (malignant) cells that surgery may have missed
  • On a single metastasis, a distant area in the body where the cancer has spread
  • For palliative care or symptom management for advanced lung cancer, including difficulty swallowing, pain, bleeding, or cough.2

Radiation therapy is often used in combination with other treatments, like surgery or chemotherapy.1,2

External Beam Radiation Therapy

External beam radiation therapy (EBRT) uses a machine that is calibrated to direct radiation beams directly to the tumor site. Prior to treatment, the radiation team determines the best angles for aiming the radiation beams and the dose of radiation that will be given. Imaging tests, such as CT (computed tomography) scans may be used to pinpoint the location of the tumor. EBRT is usually given 5 days a week for 5-7 weeks, although the actual frequency and duration may vary for the individual patient.2

To reduce the radiation exposure to nearby healthy tissues, newer EBRT techniques have been developed:

  • Three-dimensional conformal radiation therapy (3D-CRT) uses computers to map the tumor’s location and involves radiation beams directed from several directions
  • Intensity modulated radiation therapy (IMRT) uses a computer-driven machine that moves around the patient to aim the radiation beams from several angles; the radiation beams can also be modulated for different doses to limit the effects on nearby healthy tissue
  • Stereotactic body radiation therapy (SBRT) uses a specially designed body frame to reduce the patient’s movement and directs very focused high-dose radiation over fewer (generally 1-5) treatments
  • Stereotactic radiosurgery (SRS) is a form of radiation therapy that is given in only one session and may be used with surgery or instead of surgery in tumors that have spread to the brain 2

Brachytherapy/Internal Radiation Therapy

In brachytherapy, small radioactive pellets are inserted into the body at the site of the lung cancer. The pellets are inserted using a bronchoscope (tube that allows a doctor to view the airways) or during surgery. The radiation from the pellets is designed to kill the cancer and  limit effects on the nearby healthy tissues.2

Possible Side Effects of Radiation Therapy

The most common side effect of radiation therapy is fatigue, a feeling of exhaustion. Radiation therapy can also affect healthy tissue near the tumor site, and may cause redness, blistering or peeling of the skin, or hair loss where the EBRT is directed. Other side effects may include nausea and vomiting, loss of appetite, and weight loss.1,2

Written by: Emily Downward | Last reviewed: January 2017.
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