Radiation Therapy Techniques

Stereotactic radiosurgery (SRS) uses many precisely focused radiation beams to treat tumors and other problems in the brain, neck, lungs, liver, spine and other parts of the body. It is not surgery in the traditional sense because there's no incision.

SRS delivers a high dose of radiation beams on a single day, and SRT (also known as SBRT, Stereotactic Body Radiotherapy) will be done in multiple days. These treatments are performed on an outpatient basis.

Stereotactic body radiation therapy, or SBRT, is a cancer treatment that delivers extremely precise, very intense doses of radiation to cancer cells while minimizing damage to healthy tissue. SBRT involves the use of sophisticated image guidance that pinpoints the exact three-dimensional location of a tumor so that the radiation can be more precisely delivered to cancer cells.

SBRT is typically used to treat small, early-stage lung cancer and pancreatic cancer, or cancers that have spread to the lung, liver, adrenal gland, or spine.
SBRT is delivered through devices called linear accelerators, which form beams of fast-moving subatomic particles.

Image-guided radiation therapy (IGRT) is the use of imaging during radiation therapy to improve the precision and accuracy of treatment delivery. IGRT is used to treat tumors in areas of the body that move, such as the lungs. Radiation therapy machines are equipped with imaging technology to allow your doctor to image the tumor before and during treatment.

Image-guided radiation therapy (IGRT) is the use of frequent imaging during a course of radiation therapy for the purpose of improving the precision and accuracy of the delivery of radiation treatment.

Intensity modulated radiation therapy, or IMRT, is used to treat cancerous and noncancerous tumors. Radiation beams fit the shape of the tumor. The goal is to target the radiation to limit side effects and damage to healthy tissue.

This type of conformal radiotherapy uses computer-controlled linear accelerators to distribute precise radiation doses to irradiate a tumor. It offers the best protection of healthy tissue as it let radiation beams focus on the most aggressive tumor cells. This method divides the treatment field into different segments as it uses several beam angles and thousands of segments.

3D conformal radiation therapy is a cancer treatment that shapes the radiation beams to match the shape of the tumor.
Radiation beams only matched the height and width of the tumor — exposing healthy tissue to radiation. Advances in imaging technology have made it possible to locate and treat the tumor more precisely.
Conformal radiation therapy uses the targeting information to focus precisely on the tumor, while avoiding the healthy surrounding tissue.

This exact targeting makes it possible to use higher levels of radiation in treatment. More radiation is more effective in shrinking and killing tumors.
3D conformal therapy is — in many ways — like intensity-modulated radiation therapy (IMRT). They both target cancer while sparing healthy tissue.

Brachytherapy is a type of internal radiation therapy in which seeds, ribbons, or capsules that contain a radiation source are placed in your body, in or near the tumor. Brachytherapy is a local treatment and treats only a specific part of your body. It is often used to treat cancers of the head and neck, breast, cervix, prostate, and eye.

Techniques for placing brachytherapy include:
- Interstitial brachytherapy, in which the radiation source is placed within the tumor. This technique is used for prostate cancer, for instance.
- Intracavity brachytherapy, in which the radiation source is placed within a body cavity or a cavity created by surgery. For example, radiation can be placed in the vagina to treat cervical or endometrial cancer.
- Episcleral brachytherapy, in which the radiation source is attached to the eye. This technique is used to treat melanoma of the eye.