Helical tomotherapy, respiratory gated radiation therapy, and stereotactic radiosurgery
Helical tomotherapy
Another type of IMRT, this technique uses a large linear accelerator inside a doughnut-shaped contraption that spirals around a patient's body during treatment, delivering beams of radiation from many angles. Advocates believe this technique, also called a spiral CT scan, allows even more precisely focused radiation. It's also sometimes used as a screening technique as well.
Respiratory gated radiation therapy
Because radiation therapy requires such precise targeting, even the tiny movements caused by breathing, swallowing, and blood flow can throw off the radiation beams and lead to tissue damage. To solve this problem, respiratory gated treatment employs computer imaging to map radiation treatment so that the dose of radiation is modified to accommodate changes in the shape of the tumor caused by the patient's breathing or swallowing. (Without respiratory gating, doctors typically radiate the entire area that the tumor moves through as the patient breathes, which causes radiation to be delivered to healthy tissue.)
Sometimes called target motion management, this brand-new therapy increases the success of treatment for tumors in the lung, in the breast near the lung or heart, or in the neck or thyroid.
Stereotactic radiosurgery
Used almost exclusively for brain tumors, this technique aims a very high-dose radiation beam at a small area during a single session. It's the dramatic procedure you see on hospital shows during which the patient's head is enclosed inside a frame to hold it still. A related technique, stereotactic radiotherapy, uses smaller, fractional doses of radiation given multiple times. It's being studied for potential use on tumors in the lung as well as in the head.
