Radiation therapy uses high-energy rays (such as x-rays) or particles to kill cancer cells.
When is radiation therapy used?
Depending on the stage of small cell lung cancer (SCLC) and other factors, radiation therapy might be used in several situations:
- In limited stage SCLC, radiation therapy can be given at the same time as chemotherapy (chemo) 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 the chemo is finished. This is sometimes done for patients with extensive stage disease, or it can be used for people with limited stage disease who have trouble 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 spread there. This is called prophylactic cranial irradiation. This is most often used to treat people with limited stage SCLC, but it can also help some people with extensive stage SCLC.
- Radiation can be used to shrink tumors to relieve (palliate) symptoms of lung cancer such as pain, bleeding, trouble swallowing, cough, shortness of breath, and problems caused by spread to other organs such as the brain.
Types of radiation therapy
The type of radiation therapy most often used to treat SCLC is called external beam radiation therapy (EBRT). It delivers radiation from outside the body and focuses it on the cancer.
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. This planning session, called simulation, usually includes getting imaging tests such as CT scans.
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 as part of the initial treatment for SCLC is 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.
In recent years, newer EBRT techniques have been shown to help doctors treat lung cancers more accurately while lowering the radiation exposure to nearby healthy tissues. These include:
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 nearby normal tissues. This technique is used most often if tumors are near important structures such as the spinal cord. Many major cancer centers now use IMRT.
A variation of IMRT is called volumetric modulated arc therapy (VMAT). It uses a machine that delivers radiation quickly as it rotates once around the body. Each treatment is given over just a few minutes.
Possible side effects of radiation therapy
If you are going to get radiation therapy, it’s important to ask your doctor beforehand about the possible side effects so that you know what to expect. Common side effects of radiation therapy can include:
- Skin changes in the area being treated, which can range from mild redness to blistering and peeling
- Hair loss (in the area where the radiation enters the body)
- Fatigue (tiredness)
- Nausea and vomiting
- Loss of appetite and weight loss
Most of these side effects go away after treatment, but some can last a long time. 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 treatment. 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, fatigue, headaches, trouble thinking, or reduced sexual desire. Usually these symptoms are minor compared with those caused by cancer that has spread to the brain, but they can affect your quality of life.
For more information, see the Radiation Therapy section of our website.
Last Revised: 02/26/2016