External Beam Radiation Therapy and Lung Cancer

Radiation therapy utilizes high-energy beams or rays to destroy tumors. Depending on the stage of lung cancer, mesothelioma, or other diseases, the doctor may choose this treatment option. External beam radiation therapy (EBRT) is a type of radiation treatment that points the beams or rays toward the affected site from outside of the body. It’s the most common version of radiation therapy doctors choose for non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). The physician may recommend treatment by itself, or in conjunction with other cancer therapies like surgery, chemotherapy, or targeted treatments like immunotherapy and CAR T-Cell Therapy to name a few.
Graphic of 5 days a week of lung cancer treatment

The Procedure

Lung cancer patients are usually required to come in for treatment 5 days a week for up to 7 weeks. This number will vary with each patient. External beam radiation therapy is usually pain-free and only lasts a few minutes. The process for EBRT is similar to getting an x-ray, but EBRT radiation doses are much higher. Usually, patients undergo treatment and can go home the same day.

The Beams

External Beam Radiation Therapy can utilize three types of particles in their beams: photons, protons, and electrons.


Most radiation treatments utilize photon particles. Lower dosed photon beams are also applied in x-rays. These beams travel through the body and tumor, leaving bits of radiation behind.


These are positively charged particles that penetrate distant tumors without leaving much radiation behind. Proton beams are still in the testing and clinical trial phase of treatment (also known as proton beam radiation therapy) but researchers are optimistic.


Electrons have a negative charge and don’t reach very far through the body. Electron radiation therapy is reserved for skin cancer or tumors that are near the body’s surface.

Types of External Beam Radiation Therapy

There are several types of external beam radiation therapy that a doctor may recommend to their patient. Some of these techniques are newer. Types of EBRT include:

Photon Beam Radiation Therapy

Another name for External Beam Radiation Therapy, but when utilizing photon beams specifically. This is the standard version of treatment but can cause adverse reactions in patients from radiation exposure. Newer methods are being developed and tested that utilize different beams.

Proton Beam Radiation Therapy

Same as photon beam radiation therapy, but with the use of proton beams instead. Proton particles leave less radiation behind in the body when used to attack tumors. This treatment is still new and in the testing stages. Doctors believe that eventually photon beam radiation therapy may be replaced by proton therapy to reduce the radiation’s adverse effects on nearby healthy tissues.

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

A common variation of EBRT is 3D conformal radiation therapy (3D-CRT) which uses CT, MRI, and PET scan images to map out the treatment area, this part is called simulation. A computer program uses the images to develop radiation beams to match the exact size and shape of the tumor.

Image-Guided Radiation Therapy (IGRT)

A type of 3D-CRT that takes imaging scans before each treatment. CT scans are used for the process. During treatment, the radiologist can adjust the patient and re-focus the beams as needed for maximum efficiency in targeting cancer cells.

Intensity Modulated Radiation Therapy (IMRT)

Also similar to 3D-CRT except the radiation intensity is altered. In some areas, the strength of the beam may be increased or decreased so that strong doses get to where they are needed and less damage is made to nearby tissues. A type of IMRT is called volumetric modulated arc therapy (VMAT) and it uses a rotating machine to apply radiation therapy once around the body. This treatment is much shorter because of the machine speed and may only take a few minutes.

Stereotactic Radiosurgery

This type of treatment uses focused, high-energy beams to treat small, hard-to-reach tumors in just one session. Generally, this is for later-stage cancers that have spread to the brain.


Also called “slice therapy” Tomotherapy is a form of radiation that pairs intensity-modulated radiation therapy (IMRT) and computed tomography (CT) scanning technology for more accurate and effective treatment. TomoTherapy® crafts doses of radiation to match complex tumor shapes and sizes when they are located in a hard to reach or sensitive places. Before each dose, a 3D image is acquired to help target the beams and customize the dose, helping to reduce adverse effects to healthy tissues nearby.

Am I Eligible?

Your doctor will be able to assess your general health, treatment history, stage of cancer, and other important details to determine if this type of treatment is the best idea. Every patient is different and some treatments don’t go with others. Still, other patients may be too ill to move forward with radiation.

Risks and Side-Effects

Side effects differ with each patient and tumor location but tend to clear up after it’s ended. When a technician administers radiation to the chest (for pleural mesothelioma or lung cancer), the lungs or tissue nearby may take some damage. This could cause extensive coughing, trouble breathing, wheezing, or loss of breath. Confirm the details with your doctor, but other possible side effects that may come with radiation include

  • Lack of energy
  • Hair loss
    Mild redness, blistering, or peeling
  • Nausea or vomiting
  • Lack of appetite and consequent weight loss

Any reaction a patient has to radiation usually only occurs in the treatment area and usually goes away after therapy has ended. Contact your doctor if unmanageable side effects persist.