External Beam Radiation

External beam radiation is the most common form of local treatment, meaning radiation is only aimed at a specific part of the body. Doctors aim high-powered radiation beams directly at tumors from outside the body. This treatment usually happens in daily sessions over the course of several weeks.

MedStar Health cancer experts are skilled in using a variety of advanced external beam radiation methods to attack cancer. We will work with you to determine the treatment method that will be most beneficial for you. External beam radiation therapies we use include:

  • Intensity-Modulated Radiation Therapy (IMRT) allows the radiation beamlets (tiny beams) to move and change intensity depending on the type of tissue they are targeting. Rather than using one large radiation beam, the radiation is broken up into thousands of thin radiation beams. This procedure delivers high doses of radiation to the cancer tumor while limiting the exposure to nearby organs. It is a minimally invasive procedure and, therefore, may be easier on the patient than surgical procedures. IMRT accuracy is enhanced by IGRT.
  • Image-Guided Radiation Therapy (IGRT) uses high-quality imaging technology to create pictures of a tumor during the radiation procedure. Using these images, your radiation oncology team carefully adjusts radiation beams and doses during the procedure to best fit the size, shape, and location of the tumor, while sparing normal tissues. IGRT can integrate respiratory and cardiac motion technology to track the exact position of a tumor while a patient is breathing. IGRT is primarily used for patients whose tumors are directly adjacent to critical structures when an immediately adjacent area has been previously irradiated or when dose escalation is planned and where conventional means of targeting are deemed to be inadequate.
  • Stereotactic Radiosurgery (SBRT), or radiotherapy, uses imaging technology to pinpoint the location of a tumor, including its motion, and deliver very high doses of radiation directly to it without affecting surrounding healthy tissue. Since the tumor may move with breathing, we can minimize the area treated by delivering doses in between breaths (a process is called gating).
    • Trilogy Linear Accelerator: A linear accelerator is the machine most often used to deliver external beam, stereotactic radiation therapy. The specialists at MedStar Health used the Trilogy linear accelerator because, even in the highly specialized world of radiation, the Trilogy linear accelerator stands out—targeting tumors more precisely, delivering a higher dose of radiation, and requiring fewer treatment sessions. It provides:
      • Flexibility: The team of experienced medical professionals can customize treatment to target many different types of cancers in many different locations.
      • Accuracy: Radiation beams match the three-dimensional shape of the tumor with a high degree of accuracy. It also can treat smaller lesions, which allows for treatment at earlier stages when cancer is most curable.
      • Precision: IGRT and On-board Imager (OBI) help medical professionals synchronize treatment with the patient's breathing cycles. This helps to target tumors more precisely while sparing healthy tissue.
      • Speed: The Trilogy delivers radiation at a rate that is 60 percent faster than traditional linear accelerators, which enhances the patient's comfort.
      • Power: The highest dose rates can be delivered so treatments take less time and fewer treatment sessions are needed.
      • Fewer side effects: Because of the precision of the radiation, healthy tissue is spared, which results in fewer side effects.
    • CyberKnife® is one of the most advanced and effective stereotactic radiosurgery technologies, and is available at MedStar Health. Read more here.