Radiation

Radiation therapy uses high energy x-rays (photons) or particle beam (protons) to kill, shrink, control the growth of tumors, manage pain or to prevent cancer from spreading to other organs.

Radiation may be used alone or in addition to other treatments when the cancer cannot be removed by surgery or when surgery is not recommended due to other health conditions. Radiation also may be used before or after surgery.

Depending on the type of lung cancer, where it is located and other health conditions, different procedures may be recommended by your treatment team.

External beam radiation therapy (EBRT) uses precisely aimed X-ray or particle radiation beams to target tumors in the body. During treatment, you’ll lie on a table and a machine will move around you. Treatments are painless and may be given daily, multiple days a week for several weeks.

There are several types of EBRT:

• 3D-conformal radiation therapy (3D-CRT) uses CT or PET scans to create an image of the tumor and the healthy tissues around it before treatment begins. These images are used to aim the radiation directly at the tumor while protecting the healthy tissues.
• Intensity-modulated radiation therapy (IMRT) is similar to 3D-CRT but uses small “beamlets” of radiation aimed at the tumor. Radiation strength can be changed throughout treatment to protect nearby healthy tissue. It’s often used when tumors are located near other organs. It has fewer side effects than other types of external radiation, but the treatment times can be longer.
• Image-guided radiation therapy (IGRT) uses CT, MRI, or PET scans during treatment. This helps direct the beam precisely and monitor treatment progress.
• Stereotactic radiation, also called stereotactic body radiotherapy (SBRT) or stereotactic ablative radiotherapy (SABR), is a very precise form of radiation that focuses on 1 small area. This form of radiation therapy uses a very high dose of radiation and is typically given in only 1 to 5 treatments.
  • Biology-guided radiation therapy (BgRT) is a type of SBRT that uses an injected radioactive tracer and real-time PET imaging, allowing for precise targeting of the tumor and accounting for movement.
• Particle beam (proton) therapy uses a high-energy beam of protons, which are positively charged particles. At high energy, protons can kill cancer cells with much less damage to the healthy tissue near the tumor. This treatment is offered only at select centers in the U.S. and can be used in clinical trials to treat special lung cancer cases.
• Tumor treating fields (TTFields) are a different type of radiation that uses lower energy than traditional radiation therapy. It delivers a mild electrical current to the body through electrodes that are connected to a wearable device. The mild electrical current is specifically designed to disrupt the growth of cancer cells, while having little effect on healthy cells. It is approved for use in non-small cell lung cancer that has spread to other areas of the body.

Brachytherapy is radiation therapy that is implanted inside the body. Radioactive material is sealed inside needles, seeds, wires, or a small tube and placed directly into or near a tumor. It allows a high dose of radiation to be delivered inside the tumor while avoiding nearby healthy tissue. You may need to be put to sleep using anesthesia and require an overnight hospital stay when receiving brachytherapy.

Lung cancer brain metastasis (mets) is lung cancer that has spread (metastasized) to the brain. There are a few types of radiation therapy that can be used to treat brain mets. They include:

• Stereotactic radiosurgery (SRS) uses a very precise form of radiation to target a tumor and avoid nearby healthy brain tissue. It is often given over 1-5 treatments.
• Whole-brain radiation is external beam photon radiation given to the entire brain. It may be used when there are multiple areas of cancer in the brain that need to be treated.
• Hippocampal-sparing radiation may be used during whole-brain radiation to reduce the risk of memory loss, which can be a side effect of whole-brain radiation.

Prophylactic cranial irradiation (PCI) is a low-dose radiation treatment aimed at reducing the risk of brain mets in people with small cell lung cancer (SCLC). The purpose of PCI is to destroy potential cancer cells in the brain that are too small to be seen on MRI scans.

This treatment can be an option for some people with SCLC who don’t have visible brain mets on MRI. However, there is ongoing debate among experts about the use of PCI, because its benefits remain unclear and there are possible long-term side effects that can impact quality of life. For these reasons, it’s important to discuss the possible benefits and risks with your healthcare team.

For more information, see our booklet Prophylactic Cranial Irradiation: A Decision-Making Tool.