Radiation Therapy for Lung Cancer

In This Article

More than half of those diagnosed with lung cancer will receive radiation therapy at some time during their treatment. High-energy radiation rays are administered to break DNA inside cells. This causes them to die or stop dividing, which can control disease and shrink tumors. Both small-cell and non-small cell lung cancers are frequently treated with radiation therapy, which is often combined with chemotherapy, and/or surgery.

types of radiation
Verywell / Brianna Gilmartin

When Is Radiation Used For Lung Cancer?

Depending upon the type and stage of your lung cancer, radiation therapy may be used:

  • Before surgery: Radiation is administered in an effort to decrease the size of a tumor and make the procedure simpler and more likely to be successful.
  • After surgery: Doctors treat the area where they operated to ensure there are no remaining cancer cells (which may be been present but undetectable on scans).
  • As an opportunity to cure cancer: With early-stage lung cancer, radiation may be as successful as surgery for offering long-term survival. Doctors may hesitate to use the word "cured," though, since there is always the possibility of lung cancer recurring.
  • To treat lung cancer: Radiation can be used to ease symptoms or as a palliative treatment, reducing or eliminating cancer locally in the lung, nearby lymph nodes, or areas where cancer has metastasized (such as the brain).
  • As prevention: Radiation can lower the risk of recurrence or spread. In small-cell lung cancer, radiation therapy to the brain is sometimes given to kill any cells that have spread to the brain but are not detected by imaging. This is called prophylactic cranial irradiation (PCI).

When lung cancer spreads to the brain, sometimes only one or a few metastases are present. This is called oligometastases. In these instances, certain types of radiation therapy have helped people gain long-term control over the disease.

Types of Radiation

There are several ways that radiation can be used to treat cancer. The techniques vary depending on the type of cancer you have. To treat lung cancer, radiation options include external beam radiotherapy (EBRT), which comes from outside the body, and internal radiation, which uses radioactive materials placed directly inside the lung cancer tumor.

Both methods halt cancer cells, which multiply quicker and more frequently than normal cells. The cancer cells are, thus, shut down. Healthy cells can also be affected, but they are better able to repair the damage from radiation and continue working normally.

External Beam Radiotherapy (EBRT)

This is the most common type of radiation used for lung cancer. It involves high-dose radiation emitted from a machine outside the body.

There are several types of EBRT. The most common therapies used for lung cancer include:

Conventional (Two-Dimensional) Radiation Therapy

This was, historically, the only local treatment alternative for early-stage lung cancer patients with inoperable tumors.

Lacking detailed anatomical views now available with three-dimensional computed tomography (CT) technology, this form of radiation does not allow for significant accuracy and results in poor outcomes.

Three-Dimensional Conformal Radiation Therapy (3D-CRT)

This therapy improves on conventional therapy by allowing the technician to see all sides of the tumor. Radiation can be more specifically directed from different directions to match the shape of the tumor and surrounding tissue.

This method is still imperfect, however, because it relies to some degree on trial and error to get the radiation beams aimed perfectly.

Intensity Modulated Radiation Therapy (IMRT)

This is considered superior to 3D-CRT in the sense that it takes some of the guesswork out of treatments.

System algorithms determine where to place the beams and calculate the dosage of radiation to achieve optimal results. This also decreases unnecessary radiation exposure, so it can reduce toxicity related to radiation.

Stereotactic Body Radiotherapy (SBRT)

Stereotactic body radiotherapy (SBRT) is a technique in which a high dose of radiation is delivered to a relatively small area of tissue, ridding the body of cancer while sparing healthy tissue.

In contrast to other types of radiation therapy for lung cancer, SBRT sometimes offers a good chance for long-term survival or, possibly, a cure. SBRT may also be used, at times, for lung cancer that has spread. When only a few metastases from lung cancer are present in the brain or liver, SBRT has also, on occasion, resulted in long-term control of the disease.

This type of radiation is sometimes referred to by the name of the company that makes the machine being used. Some names you may hear used for SBRT include X-Knife, CyberKnife, Clinac, and Gamma Knife.

For SBRT to be effective, tumors need to be small—usually less than 5 centimeters (2 to 3 inches) in diameter. The cancer being targeted should not be too close to the airways, heart, or other critical structures.

Internal Radiation

Internal radiation involves placing a radioactive implant in your body, near the tumor. Also known as brachytherapy, it uses a thin tube called a bronchoscope to place the implant into the precise area needed. The tube is removed after treatment.

The implant may be temporary or permanent.

Brachytherapy is used more for palliative care, providing an efficient way to manage breathing difficulties that can occur as lung cancer progresses. It can substantially improve the quality of life, but it is not intended to cure cancer or prolong survival.

During Treatment

The dosage you receive, the amount of time you're exposed to radiation, and the treatment process depend on the type of radiation you undergo.

How External Therapy Is Administered

With external radiation, treatments last 15 to 30 minutes each and are usually administered daily over the course of several weeks.

Before treatment begins, you will be given one or more lung cancer tattoos, permanent ink marks about the size of a freckle overlying the tumor in your lung. This is to mark precisely where the radiation should be directed.

A simulation is then performed. During this procedure, you will need to lie very still on a table while the radiation oncologist makes adjustments to get the beam perfectly positioned. They will then calculate a dose of radiation (measured in Gy, pronounced grays) that will be delivered over the duration of your therapy.

How Internal Therapy Is Administered

For internal therapy, you usually need to be admitted to the hospital where an implant is placed during a brief operation that requires either general or local anesthesia. Your doctor will use a tube and an imaging tool (X-ray or CT scan, for instance) to place the implant in tissue near your tumor.

How long the implant stays inside your body varies, depending on the dose being administered:

  • High-dose brachytherapy: With high-dose therapy, the implant may be left in for only several minutes at a time while a large dose of radiation is emitted. Treatments may be repeated twice a day over a few days or once a day over the course of a few weeks. The application tube may be left in place until the series of radiation dosages are complete.
  • Low-dose brachytherapy: With low-dose brachytherapy, an implant may be left in for one or more days to allow it to give off low doses of radiation the entire time. Some smaller implants are never removed but will stop emitting radiation after several weeks.

Managing Radioactivity

With a radioactive implant, your body may emit a small amount of radiation for a short time. 

  • With a temporary implant, you may need to stay in the hospital with limited visitors (avoiding pregnant women and children) for the duration of your treatment. Once the implant is removed, your body may no longer give off radiation.
  • Permanent implants stop emitting radiation within a few weeks. The risk of exposure is very low with these implants, but ask your doctor to confirm whether you should take precautions.

Side Effects

There are some minor as well as some more severe side effects of radiation therapy that you should discuss with your doctor before you begin treatments.

Early Side Effects 

These problems tend to occur shortly after starting radiation. They are usually mild and should not last long:

  • Fatigue (feeling tired)
  • Skin changes.
  • Hair loss

Late Side Effects 

Side effects that can occur months or years after radiation treatment include:

While the lungs may be particularly affected for obvious reasons, complications may occur in any tissue area that was exposed to radiation. The higher the dose of radiation, the higher the risk of late side effects.

Survival rates for lung cancer are improving, which is a wonderful thing. But a longer life also means more opportunity for long-term side effects of radiation therapy to occur.

A Word From Verywell

Radiation therapy can take a while to begin working, but the benefits continue for a long time after your treatment is completed. Thus, following up with your radiation oncologist is very important. Be prepared to undergo follow-up tests and examinations to check on your progress.

Keep in mind that battling lung cancer is a long-distance run that may include continual evaluations, some setbacks, and, hopefully, many victories. As treatments continue to improve, you should be able to take advantage of more opportunities to enjoy a high quality of life as you continue your journey.

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