![Mayo Clinic home page [logo]](/images-global/mayologo.gif)
Give. Touch. Transform.
Share this site with others using one of these sharing tools.
To link to this article, paste this block of HTML code onto your webpage.
Guidelines for sites linking to mayoclinic.orgThe Department of Radiation Oncology at Mayo Clinic in Arizona offers many advanced treatment options for patients with cancer, including intraoperative radiation therapy (IORT), image-guided radiation therapy (IGRT), intensity modulated radiation therapy (IMRT) and 3-D conformal treatment.
Intraoperative radiation therapy
Cancers that have spread to nearby tissues can be radiated during surgery using intraoperative radiation. IORT is delivered to cancers that cannot be safely removed by the surgeon. It may also be delivered to the tumor bed (a narrow area surrounding the tumor removal site) after normal internal body structures have surgically moved out of the radiation field. IORT has been used as a component of treatment in patients with:
IORT is delivered using the MobetronTM, a specially designed mobile linear accelerator that produces electron beams. One IORT dose is equivalent to an additional two to five weeks of external body radiation therapy (EBRT).
Mayo Clinic is the only facility in the Southwest that offers IORT. More than 350 patients have received IORT at Mayo Clinic Hospital in Phoenix.
The use of IORT has resulted in five-year survival rates ranging from 20 percent to 40 percent for patients treated at Mayo Clinic for tumor bed or nodal relapses from colorectal, gynecologic or kidney cancer and soft-tissue sarcomas. Many institutions do not offer curative treatment options for patients with locally recurrent cancers.
Image-guided radiation therapy
Image-guided radiation therapy combines the type of X-rays used for diagnostic imaging or computed tomography (CT) scans with daily treatment radiation beams. Mayo Clinic physicians and therapists use pretreatment imaging daily to adjust radiation fields so the radiation beams do not miss the tumor or irradiate normal tissue. Special X-ray equipment is mounted on the treatment machine to make the adjustment possible.
Intensity modulated radiation therapy of the head
During powerful intensity modulated radiation therapy (IMRT) treatments, the radiation beam shapes change hundreds of times via mobile beam blocking devices. The dynamic blocking devices divide the beam into tiny beamlets of varying intensity so the radiation dose can be made to bend around normal tissues.
IMRT is a very complex form of 3-D conformal radiation therapy, in which the exact shape of the field is constantly changing during irradiation based on a computer-generated plan. Because these motions are so complicated, special computer programs are used to plan treatments and control treatment machines during the delivery of IMRT.
3-D conformal treatment of nasal cavity tumor
3-D conformal and IMRT treatment planning allow Mayo physicians to treat cancer with more accuracy and less side effects than traditional planning methods allowed.
At Mayo Clinic in Arizona, 3-D conformal treatment planning is used to treat a variety of cancers at almost every location of the body. Specialists use CT and magnetic resonance imaging (MRI) scans to identify tumors, areas of possible cancer spread, and normal organs and reconstruct them virtually (on a computer) in three dimensions.
Physicians and dosimetrists select radiation beam trajectories to treat the cancer but spare normal organs. The beams are shaped to exactly conform to the outline of the tumor, limiting radiation exposure to nearby tissues.
In brachytherapy, radioactive seeds (small pellets), wires or needles are used to deliver localized radiation in or near a tumor in an effort to destroy the cancer. Placing a concentrated dose of radiation directly in the tumor reduces the risk of damage to healthy tissue. Specialists at Mayo Clinic use brachytherapy to treat many cancers, including prostate, gynecologic (cervical and endometrial), biliary and lung cancers and soft tissue sarcomas.
In permanent brachytherapy, Mayo specialists use ultrasound, CT scans or MRI scans to place several dozen tiny radioactive seeds in a tumor. The seeds are left in place to give off low doses of radiation for weeks or months. The seeds may be placed during surgery or in a separate procedure. Permanent implants are used for prostate cancer, either as the complete treatment or as a supplement to EBRT. Read more about permanent prostate brachytherapy.
Temporary brachytherapy implants may be used as a supplement to EBRT for patients with gynecologic, biliary or lung cancers and for soft tissue sarcomas. For patients with soft tissue sarcomas and some lung cancers, the cancer is surgically removed. Hollow tubes may be placed in the surgical bed (location of the initial cancer). Catheters serve as a conduit for temporary placement of low-dose-rate brachytherapy seeds imbedded in plastic strands. The seeds are usually left in position for 30 to 50 hours, and then both the seeds and catheters are removed.
Stereotactic radiosurgery uses precisely focused radiation to treat tumors and other abnormal growths in the brain. Computers create 3-D images of the brain that guide radiation oncologists and surgeons as they aim radiation from many sources at the target area. The technology allows high doses of radiation to be delivered to the tumor with minimal exposure to surrounding healthy tissue. No incision is made and general anesthesia is not required for adults.
Stereotactic body radiotherapy is a high-dose, ultraprecise radiation treatment used to treat small lung tumors that can't be removed. Results of this treatment have been so successful that two randomized studies are being conducted to determine if stereotactic body radiotherapy is as effective as surgical treatment for early lung cancers. This technology can also be used for other body sites and tumors.
Many patients undergoing bone marrow transplant first receive a course of total body irradiation to help destroy the cancer cells in the marrow and elsewhere. Delivering an acceptably uniform dose over the entire body requires special dose measurements and treatment techniques. Total body irradiation is generally used for patients with specific types of leukemia or lymphoma.
.
