Lung Cancer (Small Cell)

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Treating Lung Cancer - Small Cell TOPICS

Radiation therapy for small cell lung cancer

Radiation therapy uses high-energy rays (such as x-rays) or particles to kill cancer cells. The type of radiation therapy most often used to treat small cell lung cancer (SCLC) is called external beam radiation therapy (EBRT). It delivers radiation from outside the body and focuses it on the cancer.

Radiation therapy may be used in several situations:

  • It can be given at the same time as chemotherapy (chemo) in limited stage disease to treat the tumor and lymph nodes in the chest. Giving chemo and radiation together is called concurrent chemoradiation. The radiation may be started with the first or second cycle of chemo.
  • Radiation can also be given after all the chemo is finished. This is sometimes done in patients with extensive stage disease or people with limited stage disease who are not able to tolerate getting chemotherapy and radiation at the same time (as an alternative to chemoradiation).
  • SCLC often spreads to the brain. Radiation can be given to the brain to help lower the chances of problems from cancer that has spread there but isn’t visible on imaging tests. This is called prophylactic cranial irradiation. This is most often used to treat people with limited stage SCLC, but it can help some people with extensive stage SCLC, too.
  • Radiation can be used to shrink tumors to palliate (relieve) symptoms of lung cancer such as bleeding, trouble swallowing, cough, shortness of breath, bone pain, and problems caused by spread to other organs such as the brain.

Before treatments start, your radiation team will take careful measurements to find the correct angles for aiming the radiation beams and the proper dose of radiation. Treatment is much like getting an x-ray, but the radiation is more intense. The procedure itself is painless. Each treatment lasts only a few minutes, although the setup time – getting you into place for treatment – usually takes longer.

Most often, radiation treatments as part of the initial treatment for SCLC are given once or twice daily, 5 days a week, for 3 to 7 weeks. Radiation to relieve symptoms and prophylactic cranial radiation are given for shorter periods of time, typically less than 3 weeks.

Standard (conventional) EBRT is used much less often than in the past. Newer techniques help doctors treat lung cancers more accurately while lowering the radiation exposure to nearby healthy tissues. These techniques may offer better success rates and fewer side effects. Most doctors now recommend using these newer techniques when they are available.

  • Three-dimensional conformal radiation therapy (3D-CRT): 3D-CRT uses special computer programs to precisely map the location of the tumor(s). Radiation beams are shaped and aimed at the tumor(s) from several directions, which makes it less likely to damage normal tissues.
  • Intensity modulated radiation therapy (IMRT): IMRT is an advanced form of 3D therapy. It uses a computer-driven machine that moves around the patient as it delivers radiation. Along with shaping the beams and aiming them at the tumor from several angles, the intensity (strength) of the beams can be adjusted to limit the dose reaching the most sensitive normal tissues. This technique is used most often if tumors are near important structures such as the spinal cord. Many major hospitals and cancer centers now use IMRT.

Possible side effects of radiation therapy

Common side effects of radiation therapy can include:

  • Sunburn-like skin problems
  • Hair loss (in the area where the radiation enters the body)
  • Fatigue (tiredness)
  • Nausea and vomiting
  • Loss of appetite and weight loss

Radiation therapy can affect the blood-forming cells in the bone marrow. This can lead to low blood cell counts. The red blood cells and white blood cells are most often affected by radiation, but sometime the platelets are affected, too. This can lead to:

  • Increased chance of infections (from too few white blood cells)
  • Easy bruising or bleeding (from too few blood platelets)
  • Feeling weak or short of breath after walking only a short distance (from too few red blood cells)

Most of these side effects go away after treatment, but some can last a long time, or may even be permanent. When chemotherapy is given with radiation, the side effects are often worse.

Radiation therapy to the chest may damage your lungs, which might cause a cough, problems breathing, and shortness of breath. These usually improve after treatment is over, although sometimes they may not go away completely.

Your esophagus, which is in the middle of your chest, may be exposed to radiation, which could cause a sore throat and trouble swallowing during or shortly after the treatment course. This might make it hard to eat anything other than soft foods or liquids for a while.

Radiation therapy to large areas of the brain can sometimes cause memory loss, headaches, trouble thinking, or reduced sexual desire. Usually these symptoms are minor compared with those caused by a brain tumor, but they can reduce your quality of life. Side effects of radiation therapy to the brain usually become most serious 1 or 2 years after treatment. For more information, please see the “Radiation Therapy” section of our website or our document Understanding Radiation Therapy: A Guide for Patients and Families.


Last Medical Review: 09/12/2014
Last Revised: 09/12/2014