Radiation Therapy

Our Approach to Treatment

Houston Methodist’s radiation oncologists are experts in the most innovative radiation therapies, which allows us to precisely target your tumor and limit radiation exposure. More than 20 years ago, we transformed head and neck cancer treatment by becoming the first health care provider worldwide to offer intensity-modulated radiation therapy (IMRT) to more precisely pinpoint tumors.

Houston Methodist continues to trailblaze radiation oncology by researching and providing the latest technologies to reduce treatment side effects. We also offer heart-sparing prone positioning (face down) to patients with left breast cancer to avoid heart and lung radiation exposure.

Additionally, our radiation oncologists work with engineers and other experts to find ways to deliver more precisely targeted and powerful therapies to eliminate tumors and save disease-free tissue.




Your radiation oncologist may recommend internal or external radiation therapy, depending on your disease.




  • Internal radiation therapy 
    • Brachytherapy – radioactive materials sealed in tiny pellets (isotopes) are placed in patients using devices, including needles or catheters. The isotopes give off radiation as they decay, which damages nearby cancer cells
      • Partial breast irradiation – a small catheter is inserted into the lumpectomy cavity. The catheter is attached to a machine that delivers radiation to the tumor site and area surrounding the cavity




  • External beam radiation therapy
    • Three-dimensional conformal radiation therapy (3D-CRT) – uses computer software and advanced machines to deliver radiation to precisely shaped targets in sites, including the brain, breast, gastrointestinal area, head and neck, liver, lung and prostate
    • Intensity-modulated radiation therapy (IMRT) – uses hundreds of radiation beam-shaping devices to deliver a single dose. The radiation beam intensity can change to allow different tumor areas or nearby tissues to receive varying radiation doses. A computer program calculates the number of beams and angles needed in sites, including the prostate, head and neck, central nervous system, breast, thyroid, lung and gastrointestinal area
    • Image-guided radiation therapy (IGRT) – repeated CT, MRI or PET scans are performed during treatment to increase target accuracy and spare normal tissue. Computers process the scans to identify tumor size and location changes so the patient’s position or radiation dose can be adjusted during treatment in areas prone to movement, including the lungs, liver, prostate, breast and tumors near critical organs and tissues
      • Tomotherapy – a type of image-guided therapy. A tomotherapy machine is a combination CT scanner and external-beam radiation therapy machine. It images a patient’s tumor before treatment to allow for precise tumor targeting
      • Prone breast radiation therapy – lying face down to receive radiation therapy, reducing radiation that reaches the heart and lungs
    • Stereotactic radiosurgery (SRS) – uses accurate image-guided tumor targeting and patient positioning to deliver high radiation doses to the brain and lungs while limiting damage to normal tissue
    • Stereotactic body radiation therapy (SBRT) – delivers radiation therapy to small, isolated tumors in fewer sessions using smaller radiation fields and higher doses at sites, including the lungs, liver, abdomen, spine, prostate, breast and head and neck
    • Stereotactic radiation therapy (SRT) – Is similar to stereotactic radiosurgery, but delivers lower radiation doses to brain tumors on multiple days




Radiation Therapy Technologies

  • TrueBeam – delivers powerful, accurate and fast image-guided treatments
  • Novalis – an image-guided system that precisely forms a radiation beam around a tumor while protecting the healthy tissue
  • TomoTherapy – confirms a patient's tumor before treatment and precisely delivers radiation therapy
  • Varian Clinac 21EX – provides accurate, full-dose ranges for intensity-modulated radiation therapy and image-guided radiation therapy
  • Phillips CT Simulator – provides precise and flexible scanning and dosing delivery
  • Varian High Dose Rate (HDR) Afterloader – includes a computer-based management system allowing for proper placement, replacement and dosing