Radiation Therapy is one method used for treating certain malignant, as well as some nonmalignant, conditions. This treatment uses high-energy rays and electron beams to interrupt the growth of cells.
Machines called linear accelerators use electricity to create painless, high-energy x-rays and electron beams. These rays are beamed into your body during treatment. The radiation oncologist, a specially trained physician, will decide the dosage, technique and type of radiation to be used for your treatment.
There are various types of radiation treatments available for specific conditions. Your physician will discuss with you the type of treatment that can help you the most.
The following is a list of what is available at the University of Toledo.
| 3D Conformal External Beam |
This type of treatment is administered by linear accelerator machines that are capable of delivering high-energy radiation. At University of Toledo Medical Center (UTMC), the energies used for treatment of cancer are 6, 10, and 18 MV photons and a range of electrons from 6 to 20 MeV. The measured output data from these machines are entered into the treatment planning system computers and for each patient a treatment plan is projected. The treatment plan generated by a dosimetrist/physicist is implemented after it is reviewed by a radiation oncologist. Some of the 3-D treatment plans generated for patients at UTMC are displayed in a slide show.
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Occasionally, a surgical procedure may be necessary to implant or place radioactive sources in an anatomic site which is involved with cancer. Usually these procedures are carried out in the operating room under the usual sterile and surgical methods necessary for other types of surgery. Either general or local anesthesia may be required and certain restrictions will be temporarily made in patent's activities. Methods of delivering brachytherapy dose include intracavitary or interstitial placement of sources, instillation of colloidal solutions, and parenteral or oral administration. At the department of radiation oncology, these options are available to patients in the form of encapsulated sources of radiation (Cs-137), Wires for interstitial therapy and permanent implants such as Au-198 or I-125 seeds. These implants provide radiation to a limited area which minimizes the exposure to normal tissues. Common sites of treatment for these implants include cancers of the tongue, lip, breast, vagina, cervix, endometrium, rectum, bladder and brain. Strontium 90, a beta ray applicator is used at UTMC to treat pterygium, a benign condition of cornea, and Strontium-89 coloride is given intravenously for bone pain palliation. For other lesions radioactive isotopes are administered orally , parenterally, or instilled into intrapleural or peritoneal spaces. Iodine-131 for example, is frequently used for treatment of thyroid cancer by oral administration.
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| Intensity Modulated Radiation Therapy |
The University of Toledo iMedical Center (UTMC) isn’t new to cutting-edge cancer treatment. UTMC has a history of leadership in cancer care. The Radiation Oncology Department offers the most sophisticated cancer treatments in the country, including intraoperative radiation, stereotactic radiosurgery, high dose-rate brachytherapy and now intensity modulated radiation therapy.
The goal of radiation therapy is to deliver precise, even doses of radiation to a malignant site while avoiding contact with healthy tissue. Intensity Modulated Radiation Therapy, or IMRT, can intricately direct a beam of radiation to its target from a variety of angles. It allows physicians to minimize “hot spots” that can be accompanied by painful skin irritations. New computer technology has made IMRT possible and allows it to be included in the range of therapies available to our patients.
UTMC uses cutting-edge technology in designing radiation treatment plans that are highly customized to each and every patient. The system evaluates many possible combinations of radiation beam shape, size and angles to help UTMC radiation oncologists create the best possible treatment plan for each patient.
When the diagnosis is cancer, treatment options must carefully be weighed to identify the most effective option with the least side effects. Even after radiation is chosen as a course of treatment, a variety of methods, including IMRT, may be considered. Often radiation will be used along with surgery, chemotherapy or a combination of the two.
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| Intraoperative Radiation Therapy |
A procedure in which a dose of radiation is delivered to a surgically exposed tumor or tumor bed while normal organs are shifted from the field. The radiation oncologist brings an electron applicator of appropriate size and shape into contact with the affected area to be treated and delivers a dose of radiation directly to the tumor.
Since 1983, UTMC has been the sight of nearly 400 IORT procedures. We are the only facililty in northwest Ohio that offers this modality of treatment. Our center is one of a few in the world that has a dedicated surgical suite just next to the radiation suite for the purpose of intraoperative radiation therapy.
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| Partial Breast Irradiation Treatment |
Cancer specialists at the University of Toledo Medical Center (UTMC) are using a new procedure that cuts radiation time down.
The "Mammosite" catheter allows UT MCcancer physicians to treat select early-stage breast cancer patients who undergo lumpectomies with localized radiation therapy that shortens radiation time to five days.
During the procedure, also known as breast brachytherapy, surgeons perform a traditional lumpectomy to remove the cancerous tumor. They then place a small, soft balloon attached to a thin catheter, or tube, inside the lumpectomy cavity in the breast through a small incision during surgery. The balloon is inflated and it remains inside the breast during radiation treatment.
The patient visits UTMC twice a day for five days, at which time a sophisticated, computer-controlled machine known as a high dose rate brachytherapy unit delivers a radioactive seed through the catheter to the inflated balloon. The seed remains inside the breast for about 15 minutes to deliver the radiation directly on the lumpectomy tissue before the seed is retracted back into the machine.
University of Toledo Medical Center is the first hospital in northwest Ohio to have the special computer-controlled machine.
Not all breast cancer patients are candidates for the new therapy. Selection criteria calls for patients to be 45 years of age or older with early-stage breast cancer, a tumor size less than three centimeters (about an inch) with clear margins and no lymph node involvement.
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One of the greatest challenges facing radiation oncology today is the delivery of high radiation dose to the tumor while sparing the surrounding and normal tissues. UT is one of the six sites in the country that provides this type of therapy.
This new treatment technique, known as infusional brachytherapy, uses colloidal P-32 to treat various neoplasms and is ideal for tumors that are non-resectable and have a diameter of less than 5 cm or a volume of less than about 65 cm3. It has already been used for treating tumors in the pancreas, liver, brain, lung, and head and neck. A team of professionals consisting of a radiation oncologist, physicist, nuclear medicine physician, interventional radiologist and diagnostic radiologist carry out the procedure. The interventional radiologist will first locate and insert a biopsy needle in the middle of the tumor, while the radiation oncologist will then inject the tumor directly with P-32 under CT guidance. A bremsstrahlung SPECT study using Tc-99m backscatter sources to obtain the body contour is then performed. The SPECT images are used to generate the skin contours using a threshold detection method. Using our in-house developed 3-D treatment planning system, we have developed a clinically applicable methodology that can be used to determine the 3-D absorbed dose from bremsstrahlung SPECT images of these patients. A map of the two-dimensional isodose distributions is generated and projected on the reconstructed SPECT images. The SPECT images can also be fused with CT images. This technique has been extended to calculate the quantitative dose for the entire volume and iso-surface dose distributions can be generated in 3-D.
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| Stereotactic Radiosurgery |
Stereotactic Radiosurgery is a procedure that relies on complex brain mapping techniques and computer technology. The patient undergoes CT scanning that takes painless cross-sectional pictures of the brain. Once the CT data are gathered, the physics team enters the data into a high-powered computer. The tumor regions and important brain structures are carefully outlined. The computer reconstructs the anatomical structures in 3D using the graphics programs developed at UTMC. The software identifies potential crossing of radiation beams with critical structures in the brain such as the eyes, optic nerves, brain stem and the internal capsule that carry nerve bundles to the spinal cord.
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