Radiation Therapy

Radiation uses powerful, high-dose X-rays to kill lung cancer cells or stop their growth. There are several forms of external and internal radiation therapy. External radiation involves focusing radiation at your lungs from a radiation machine. Internal radiation involves placing small pieces of radioactive material inside your lungs near cancer cells. External radiation is more common.¹

Radiation is performed by doctors called radiation oncologists. They work with other specialists to figure out the right kind of radiation for you. They also calculate the amount of radiation you need. Using the lowest possible radiation dose helps reduce damage to healthy cells.²

When is radiation therapy used?

Radiation therapy may be used in several situations. It is most often used:^1,3,4

• With chemotherapy to treat cancer in multiple ways
• Instead of chemotherapy for those who do not want chemotherapy or do not respond to chemotherapy
• Instead of surgery for those who do not want surgery or are not healthy enough to have surgery
• Before surgery, to shrink cancer cells and make them easier to remove
• After surgery or chemotherapy to kill any remaining cancer cells
• To reduce the chance that cancer reaches the brain (specifically, small-cell lung cancer)
• For palliative care to relieve symptoms like pain or difficulty breathing

Radiation has often been used to treat early-stage cancers. Radiation oncologists now understand that radiation may also be an effective option for some later-stage cancers. It can slow down late-stage cancer in certain situations so that it does not progress further.⁵

External beam radiation therapy (EBRT)

EBRT is a type of external radiation. It is similar to an X-ray but uses a much stronger dose. The treatments are painless and usually last only a few minutes at a time.⁴

Schedules for EBRT vary based on your specific type of lung cancer and other factors. A common schedule includes 5 radiation treatment days per week for multiple weeks. There are several types of EBRT, including the following.⁴

Stereotactic body radiation therapy (SBRT)

This is also called stereotactic ablative radiotherapy (SABR). SBRT is best for early-stage cancer when surgery cannot be done, or you do not want surgery. It uses stronger radiation but requires fewer treatments. You will be fitted for a body frame that keeps your body still during treatments. This way, the radiation hits only a very specific area.⁴

3-dimensional conformal radiation therapy (3D-CRT)

This treatment uses special computers to map out your tumors. Radiation beams are angled in different directions to hit the tumor from multiple sides. 3D-CRT is less likely to damage healthy tissues around the tumor.⁴

Intensity-modulated radiation therapy (IMRT)

This is an advanced 3D-CRT in which radiation beams match the shape of your tumor. In this kind of therapy, the strength of the beams can change throughout the treatment. IMRT is most often used when tumors are near vital organs or structures like your spinal cord.⁴

4-dimensional conformal radiation therapy (4DCT)

4DCT tracks the movement of a tumor during your breathing cycle. It is called 4-dimensional because it adds the dimension of time to 3D-CRT.^3,4

4DCT may be used when tumors are near or attached to healthy structures. Doctors can deliver radiation at the point in the breathing cycle when the tumor is in the best spot. This can reduce damage to nearby healthy tissue.^3,4

Stereotactic radiosurgery (SRS)

Despite its name, this procedure is not surgery. SRS is done in a single session. It can last from a few minutes to a few hours. It focuses about 200 beams of radiation over the tumor using different angles. It is sometimes used instead of or with surgery for a single tumor that has spread to the brain. SRS can be repeated if needed.⁴

Proton therapy

Another type of external radiation called proton therapy may be used to treat non-small cell lung cancer (NSCLC). It uses radiation from protons instead of X-rays. Protons are positively charged particles that can be targeted to a tumor.⁴

Protons release the most radiation as they hit the tumor, then stop. This causes less damage to nearby healthy organs than X-rays, which release radiation before and after contacting the tumor location. Proton therapy is mostly offered in specialized treatment centers.⁴

Brachytherapy

One common form of internal radiation therapy is called brachytherapy. With this technique, small pellets of radioactive material are placed in the lung near your tumors. These can be placed during surgery or during a procedure where a camera looks at your airway (bronchoscopy).⁴

The pellets are usually taken out after a short time. Permanent radioactive “seeds” that degrade over weeks may be placed, but this is less common.⁴

What are the possible side effects?

Side effects can vary depending on the specific location of the radiation. Some general side effects include:⁴

• Fatigue
• Nausea
• Vomiting

Others affect just the site of the radiation, such as:⁴

• Redness
• Peeling
• Hair loss

A sore throat and problems swallowing are also common. Side effects usually go away after treatment.⁴

These are not all the possible side effects of radiation therapy. Talk to your doctor about what to expect with radiation therapy. You should also call your doctor if you have any other questions or changes that concern you about radiation therapy.

Before beginning treatment for lung cancer, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.