Linear Accelerator Treatments

Linear Accelerators, also known as linacs, are devices used to treat cancer.  They are most commonly used for external beam radiation treatments.  Linacs work by speeding up electrons to deliver therapeutic X-rays or electrons to a patient’s tumor.  These treatments can be designed in a way that they destroy the cancer cells while sparing nearby surrounding normal tissue.  Linacs can be used to treat all body sites using conventional techniques as well as more sophisticated techniques like intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT), image guided radiation therapy (IGRT), stereotactic radiosurgery (SRS), and stereotactic body radiation therapy (SBRT).

Intensity-Modulated Radiation Therapy (IMRT) is a cancer treatment that matches radiation intensity to the shape of a tumor.  IMRT allows doctors to customize the radiation dose and volume by varying the amount of radiation given to different parts of the treatment area.  This technique is used to maximize tumor coverage while minimizing radiation exposure to normal surrounding tissues.

Volumetric Modulated Arc Therapy (VMAT) is another type of IMRT where the linear accelerator rotates around the patient while delivering radiation at the same time.  This process increases the number of beams while decreasing the high dose radiation to normal tissues.

Image Guided Radiation Therapy (IGRT) is a method of radiation that incorporates imaging techniques during each treatment session.  IGRT ensures that our therapeutic radiation beams are narrowly focused at the treatment area.

Radiation Motion Management is a technique necessary to minimize normal tissue dose in cancers that have motion during treatment. For instance, lung tumors move with respiration and abdominal tumors move with both respiration and abdominal filling.  There are a variety of methods to limit motion for tumors that move, including respiratory gating and abdominal compression devices.  In addition, some tumors like breast tumors can be ideally positioned to avoid the heart by utilizing breath hold techniques like deep inspiratory breath hold, also called DIBH for short. An MRI linac allows detailed tumor and normal anatomy imaging, while also allowing daily adaption based on tumor anatomy and respiratory gating to ensure that the tumor is only treated when it is in an optimal position.

Innovative Applications at UVA
UVA has four different linear accelerators that offer conventional radiation, IMRT, VMAT, IGRT, SRS, SBRT, and other treatment modalities.  We also have an MRI linac for difficult to treat tumors that require daily adaptive planning.  UVA offers respiratory gating utilizing a variety of approaches.  These technologies allow our radiation oncologists to treat complicated tumors while minimizing treatment associated side effects.  The radiation oncologist will determine which technique is right for you.  Read more about some of the innovative research being done at UVA utilizing our linear accelerators.