Radiation Therapy for Lung Cancer

Many patients with lung cancer will be treated with radiation therapy. Radiation therapy uses radiation beams to damage cancer cells and shrink tumors. It’s a well-established form of treatment that can benefit lung cancer patients in a number of ways. In patients with early-stage lung cancer, radiation therapy may be enough to cure the disease.

Today, radiation therapy can even extend the lives of some patients with metastatic cancer. This is possible now because new drugs are enabling patients to live longer and allowing for further treatment.

If you come to Siteman Cancer Center to be treated for lung cancer, our Washington University radiation oncologists will be able to treat you with the safest, most advanced forms of radiation therapy.

We are international leaders in developing new ways to deliver radiation precisely and effectively.

Our facility houses every type of radiation therapy machine and tool available, so your oncologists will be able to match you with the ideal radiation treatment plan for your condition.

Learn more about how radiation therapy at Siteman Cancer Center can help you.

What is it like to receive radiation therapy?

It’s normal to have lots of questions before beginning radiation therapy. Patients sometimes worry that the procedure will be painful, or that the radiation will make them “toxic” in some way. It can also seem daunting to fit regular therapy appointments into your daily schedule.

In reality, radiation therapy is a painless procedure. Patients can’t feel the radiation beam, and it only takes a few minutes to deliver the treatment. Often, more time is spent ensuring that the patient is in the correct position and that the machine is properly aligned than actually conducting the therapy. However, this careful planning is crucial to achieve the best results.

Your care providers at Siteman will work hard to ensure than you move through the process as smoothly as possible. Our department concentrates on minimizing side effects and helping patients maintain their quality of life during and after treatment.

What forms of radiation therapy are used to treat lung cancer at Siteman?

Radiation oncologists at Siteman use a number of different methods to deliver radiation therapy:

  • Intensity-modulated radiation therapy
  • Image-guided radiation therapy
  • MRI-guided radiation therapy
  • Proton beam therapy
  • Brachytherapy
  • Stereotactic body radiation therapy (radiosurgery)

Intensity-modulated radiation therapy

Intensity-modulated radiation therapy, or IMRT, uses radiation beams of varying strengths to precisely cover the 3-dimensional shape of the tumor. It allows the radiation oncologist to treat the tumor while avoiding normal tissues nearby. This makes intensity-modulated therapy an excellent option for tumors located in the lungs, given their proximity to the heart. It’s often used for patients with larger tumors.

Patients undergo IMRT daily, Monday through Friday, usually for a period of a few weeks.

Image-guided radiation therapy

Lung tumors can be challenging to target with radiation because they move as the patient breathes. To account for this, intensity-modulated therapy may be enhanced by cone-beam CT imaging. This procedure, known as image-guided radiation therapy (IGRT), enables the treatment team to target the tumor more accurately and and make adjustments promptly, especially if the tumor is changing through the course of treatment.

Stereotactic radiation therapy

Stereotactic radiation therapy is a special way of delivering radiation in high doses. Because the doses are high, patients don’t need as many treatments. The entire course of radiation therapy can be completed in a week or two, or even a few days. This makes it different from IMRT, in which the doses are smaller and spread out over a long period of time.

Stereotactic radiation therapy is a method, rather than a specific machine. Your physicians may refer to it as “radiosurgery” because it can eliminate tumors just as effectively as a single surgical procedure.

Lung cancer patients with smaller tumors, or patients at stages I and II, are usually the best candidates for stereotactic therapy.

MRI-guided radiation therapy

MRI-guided radiation therapy, or MRgRT, is a new form of image-guided radiation therapy that allows radiation to be delivered to a tumor while simultaneously imaging the tumor with an MRI. MRgRT is particularly helpful for the treatment of cancers near organs that move on a daily basis due to breathing or digestion. MRgRT also allows for the radiation treatment plan to be modified each day to take into account the new position of the nearby organs. Siteman was the first cancer center in the United States to use this technology and has pioneered its development.

Proton beam therapy

Proton beam radiation therapy uses particles called protons to kill tumor cells. The main advantage of proton beam therapy is that specialists can control the proton beam’s shape and where it stops in the body. This means that the beam won’t pass through your body; instead, it stops directly within the tumor, without touching any healthy tissue beyond it.

Proton beam therapy is ideal for patients with solid tumors that are located near sensitive structures or tissues, such as the heart. It can be used as a solo treatment option for localized lung cancer, or it can be used in combination with chemotherapy.

The S. Lee Kling Proton Therapy Center at Siteman was the first proton therapy center located in Missouri and the surrounding region. It houses the world’s first compact proton beam accelerator. Washington University radiation oncologists and physicists helped evaluate the system and developed the patient protocols and quality standards for this advanced technology.


Brachytherapy is a form of internal radiation therapy. This means that the radiation is implanted inside the tumor, rather than transmitted from a machine. It allows less radiation exposure to surrounding organs.

The radiation used for brachytherapy is contained in tiny seeds. After being implanted in the tumor, they will release the radiation over a period of time ranging from minutes to days.

Why Siteman?

Siteman’s radiation oncology team has pioneered new methods that target lung tumors and avoid radiation damage to surrounding normal tissue. They often use MRI to help guide radiation therapy treatments in real time, which allows the team to see where the dose is being delivered and decide whether adjustments are needed.

Radiation oncology has active trials for minimizing the duration and amount of radiation a patient receives to reduce long-term side effects. The goal of the radiotherapy trials is to ensure that no one is over or under treated. Siteman is a leader in using shorter durations of radiation treatment for lung cancer with the same, or better, outcomes.