Radiation medicine

We offer the most current treatments available:

External beam radiation therapy

3-D conformal radiation therapy

Intensity-modulated radiation therapy

Brachytherapy

GliaSite radiation therapy

External beam radiation therapy

Used to treat many types of cancer, external beam radiation therapy uses a linear accelerator, a high-energy X-ray machine, to direct radiation to the tumor. The procedure typically takes about 15 minutes, usually for five days a week, over the course of six to eight weeks.

Before radiation treatment begins, a planning session or simulation is required to pinpoint the tumor and determine the treatment series. Simulation may take up to an hour.

External beam radiation therapy poses no risk of radioactivity to the patient or to those with whom he or she comes in contact. Patients can continue normal activities with family and friends.

In the case of prostate cancer, radiation works more effectively on small and moderately sized prostate glands. Men with very large prostate glands often undergo a 3- to 6-month course of hormone therapy to shrink the prostate gland before radiation therapy.

3-D conformal radiation therapy

The goal of three-dimensional conformal radiation therapy is to shape the prescribed radiation to the target. In the past, radiation therapy plans were reviewed in a two-dimensional plane. The radiation dose above and below the plane was assumed adequate, but could not account for changes in the shape or contour of an organ or tumor.

Three-dimensional conformal radiation therapy accounts for the size, shape and mass of the tissues. A 3-D visualization allows the radiation oncologist to choose various radiation therapy beam arrangements to hit the tumor while minimizing the exposure to healthy tissue. Patient positioning is critical, so immobilization devices are routinely used.

Intensity-modulated radiation therapy

Intensity-modulated radiation therapy (IMRT) is an advanced form of 3-D conformal radiation therapy. Not everyone is a candidate for IMRT, but for those who are, it is one of the most precise forms of external beam radiation therapy available.

In some cancer patients, conventional radiation treatment cannot achieve the desired effect without the risk of damage to surrounding tissue. IMRT uses sophisticated software and equipment to vary the shape and intensity of radiation delivered to different parts of the treatment area. Because the radiation is conformed even more tightly to the tumor, there is less risk of damage to normal tissues. And doctors can deliver a larger dose of radiation to the tumor with the confidence that the dose is highly targeted.

IMRT is useful in treating many types of cancer, and is performed on an outpatient basis. Most patients receive about six weeks of treatment.

Brachytherapy

Derived from ancient Greek words for "short distance" (brachy) and "treatment" (therapy), it is sometimes called seed implantation. Brachytherapy is an outpatient procedure used in the treatment of several different diseases, including prostate cancer, cervical cancer, endometrial cancer and coronary artery disease.

Small radioactive metal spheres, or "seeds," are carefully placed inside the cancer, or in the case of coronary artery disease, scar tissue, and positioned in a way that will attack the tissue most efficiently. Brachytherapy has been proven effective and safe, providing a good alternative to surgical removal of the prostate and cervix, while reducing the risk of some long-term side effects.

In the treatment of prostate cancer, the radioactive seeds are about the size of a grain of rice, and give off radiation that travels only a few millimeters to kill nearby cancer cells. There are two different kinds of brachytherapy: permanent, when the seeds remain inside of the body, and temporary, when the seeds are placed inside the body then removed. With permanent implants, the radioactivity of the seeds decays with time while the actual seeds remain in the treatment area.

GliaSite radiation therapy

The GliaSite Radiation Therapy System is a method for treating newly diagnosed, metastatic and recurrent brain tumors. Radiation is delivered from within the cavity created when the tumor is surgically removed. Being a site-specific, internal radiation treatment, this form of brachytherapy delivers a high dose directly to the surrounding tissue of the original cancer site, thereby radiating the area of greatest recurrence. The therapy minimizes radiation exposure to healthy brain tissue and is less disruptive for the patient. Treatment time is shortened to less than a week, as compared to six weeks with an external beam. Side effects are minimal, making for a better quality of life for the patient.

When the tumor is removed, a balloon catheter is implanted and filled with saline and a contrast solution to determine the appropriate volume. For additional safety, the balloon catheter is actually a double balloon. The patient is discharged after a short postoperative intensive care stay, then returns several days later for an MRI to assess the conformance of the catheter to the cavity.

The radiation oncologist plans treatment by determining the radiation dose and treatment depth. He or she then deflates the balloon and refills it to the same volume with a combination of liquid radioactive iodine and saline. This solution emits radiation that directly targets the area while minimizing the exposure to healthy tissue. The balloon delivers radiation for three to seven days; the length of time is dependent upon the radiation oncologist's treatment plan. Patients remain hospitalized during the course of treatment and may have visitors. After the treatment time is complete, the radioactive solution is withdrawn and the catheter is removed.

Last updated September 22, 2004