Radiation Therapy for Lung Cancer

Radiation therapy for lung cancer is one treatment option. The others are surgery and chemotherapy. Radiation has been used for cancer treatments for about a hundred years.

The research work of Nobel prize-winning scientist, Marie Curie, began the use of radioactive elements in medical treatments. This was in the early part of the twentieth century. In the 1940s linear accelerators came into use. Cobalt and cesium were the chemicals they employed. In 1971, Godfrey Hounsfield invented computed tomography (CT). Three-dimensional imaging became possible.

The newest technologies include: magnetic resonance imaging (MRI) since the 1970s; and, positron emission tomography (PET) since the 1980s. They have moved radiation therapy from 3-D conformation to intensity-modulated radiation therapy (IMRT) and image guided radiation therapy (IGRT). These therapies result in better treatment outcomes and fewer side effects.

Radiation Mechanism

Radiation therapy for lung cancer or radiotherapy is the medical use of radiation to control malignant cells. It works by damaging the DNA of the cells. A photon, electron, proton, neutron or ion beam directly or indirectly strips the atoms that make up the DNA chain. This causes the damage. The DNA damage is inherited through cell division causing the cancer cells to die or reproduce more slowly.

The unit of radiation is “the gray (Gy).” The gray was defined in 1975 in honor of Louis Harold Gray (1905–1965), who derived the unit from the roentgen, a measure of radiation emitted. A normal dose can range between 20 and 80 Gy depending on the type of tumor.

Radiation Uses

Lung cancer radiation is a therapy to treat both small cell lung cancer and non-small cell lung cancer. This treatment for lung cancer is often combined with chemotherapy and/or surgery.

Radiation therapy for lung cancer may be used:

• After surgery to treat any cancer cells that might remain
• Before surgery to decrease the size of the tumor
• To cure cancer that is a small tumor, and in patients who cannot tolerate surgery
• To treat lung cancer in the lymph nodes or other parts of the body
• To treat symptoms such as shortness of breath and pain
• For prevention to kill any cells that have spread to the brain

Types of Radiation Therapy For Treatment for Lung Cancer

Lung cancer radiation can be given externally or internally to treat your cancer. Some procedures include:

• Conventional or two-dimensional x-ray radiation
• 3D conformal or computed tomography (CT) guided radiation. This directs the radiation more specifically.
• Intensity Modulated Radiation Therapy (IMTR) provides a higher dose of radiation. It is a specialized form of 3D-CT that varies the intensity of the radiation.
• Stereotactic body radiation is being studied with select patients. It, too, is a specialized form of 3D-CT that delivers high doses to small and very precise locations.
• Radiation that uses beams of protons instead of X-rays. It is only available in a few clinics.
• Internal radiation or brachytherapy inserts a thin plastic tube with a small amount of radioactive material to a precise area of your lung. The material is only the size of a seed or a narrow ribbon. It is usually radioactive iodine or strontium or phosphorus or cobalt.

Side Effects of Lung Cancer Radiation

Some of the side effects you may experience after radiation therapy for lung cancer include:

• Fatigue related to low red blood cell counts. It is temporary. You can pace yourself and rest when you are tired.
• Skin reactions at the site of the radiation are not severe. Do not use lotions before treatment. Try not to scratch the area and wear loose clothing.
• Esophagitis is the irritation and inflammation of the lining of the esophagus (tube from the throat to the stomach). Switching to soft foods and liquid supplements may reduce some of the pain in swallowing.
• Radiation pneumonitis is the most significant side effect of treatment for lung cancer. You might have:
  • a non-productive cough
  • a low-grade fever
  • shortness of breath
  • chest pain and generalized fatigue. These symptoms occur in 30% of the patients. The most common prescription for pneumonitis is the steroid prednisone for several weeks.
• Pulmonary fibrosis is scar tissue in the lung from the damage from radiation. This pulmonary fibrosis may be chronic and lead to permanent lung function impairment. Up to 70% of lung cancer patients with radiation therapy will develop pulmonary fibrosis.
• Damage to nerve tissue and other organs can occur. There is a collection of nerves called the brachial plexus that control arm and hand motion. Damage to the nerves can lead to numbness or weakness or even paralysis. Since the heart is in the chest cavity, it could receive some radiation but that is minimized using the 3D-CT scans.

Lung cancer patients cannot be overwhelmed by these side effects because lung cancer radiation is an integral part of your treatment for lung cancer.

Research in Lung Cancer Radiation

In March 2009, Temple University radiologists said the new technique –stereotactic body radiotherapy – could improve the odds of surviving early stage lung cancer. For those who are given SBRT the two-year survival rate increases to approximately 81% and can reach up to 98%. It actually cured half of the lung cancer patients.

It can be scary when they tell you about lung cancer, but there is still hope and you should not give up on that hope. There are treatment options out there that can help you and there are clinical trials always being done. Having to get radiation therapy for lung cancer is scary, and it will be hard, but it is possible to overcome.

Written by Margaret Stenerson-Reynolds
Reviewed by Susan McCracken