Radiation Therapy
What Is the Goal of Radiation Therapy?
The goal of radiation therapy depends on your specific type of cancer and your overall health. Generally, radiation therapy is designed to achieve one or more of the following results:
- Stop the growth of cancer cells to reduce their size before surgery or stop their growth after surgery.
- Improve your quality of life. Even if it’s not possible to cure certain cancer cases, radiation therapy may still improve symptoms and provide relief from pain and discomfort.
- Reduce the possibility of metastases, or disease spreading to other locations or organs within the body.
How Do I Get Radiation Therapy?
Radiation therapy is given in doses measured in grays or centigrays for several weeks. Radiation may be delivered either externally or internally.
External radiation is the most commonly used type. In external radiation, high-energy X-rays are directed at the cancer cells from the outside of your body.
Internal radiation, also called brachytherapy, is delivered from within your body in the form of precise amounts of radioactive material in an implanted device such as a catheter or other type of applicator. The radioactive material remains in place for the time required to destroy the cancer cells. That may be a short period of time or the material may be implanted permanently.
How Do Doctors Target the Radiation Therapy?
Today’s advanced technologies combine radiation delivery with different types of imaging, which allows the radiation oncologist to see a picture of the area to be irradiated. This means that the oncologist can more precisely target tumors with the radiation. More precise targeting results in a smaller area of healthy cells exposed to the radiation, which means fewer side effects.
Intensity Modulated Radiation Therapy (IMRT) is an advanced form of radiation treatment that allows radiation oncologists to precisely target tumor cells. It is a non-invasive therapy that uses Computed Tomography (CT) and often other imaging techniques to build three-dimensional diagnostic images and support treatment planning to deliver tightly focused radiation beams of varying intensity to cancerous tumors without needles, tubes, or catheters. By varying the intensity of these beams, physicians can maximize dosage to the tumor and minimize the amount of radiation distributed to the surrounding healthy tissues. IMRT has been shown to be particularly useful for cancers of the prostate and head and neck region as well as potentially beneficial for treating breast, pelvic, and any tumor wrapping itself around critical organs or tissues.
Image-guided radiation therapy (IGRT) combines a new form of scanning technology with the control of IMRT to pinpoint and treat cancerous tumors with varying amounts of radiation. Using imaging modalities to precisely localize the tumor during each session adds safety and accuracy. IGRT is used to treat tumors in areas of the body that are prone to movement, such as the lungs, liver, and prostate gland, as well as tumors located close to critical organs and tissues.
Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT) both of these treatments deliver extremely precise doses of radiation to cancer cells while minimizing damage to healthy tissue. Stereotactic Radiosurgery (SRS) treatments use high-precision, accurate, and sophisticated 3D imaging to deliver radiation in as little as a single treatment. Stereotactic body radiation therapy (SBRT) delivers precise radiation for the treatment of small-to-medium-size tumors in the body. SBRT is usually prescribed for one to five sessions over the course of one to two weeks. This upgraded technology offers new hope to patients who have inoperable or surgically complex tumors such as early-stage lung cancers, pancreatic cancers, brain tumors or as an alternative to whole brain radiation for appropriate spinal tumors, and cancers that have metastasized to the brain. These treatments are non-surgical, non-invasive, painless and are typically performed in an outpatient setting.
High Dose Rate (HDR) brachytherapy is an advanced treatment for internal radiation. Like IMRT and IGRT, HDR allows doctors to deliver precise radiation therapy to your tumor. HRD is frequently used to treat cervical and uterine cancers and certain kinds of lung and esophageal cancers. Recently, it has also proven effective in treating early stage prostate cancer.
What is a Radiation Therapy Session Like?
A radiation therapy team consists of a radiation oncologist, a radiation therapist (who delivers the radiation therapy), physicists and dosimetrists, who all work together to develop your treatment plan and dosage calculations.
Before your treatment, you will have a simulation session where your team will map out the location(s) for your radiation therapy using either a CT scanner or x-ray positioning. Small reference marks called tattoos will be marked on your skin to help your team to target your treatment on a daily basis.
Your team will make sure you understand everything that will happen before you go in for your first treatment. Generally, you won’t feel anything during treatment, and many people arrange their treatment around their work schedules or other daily commitments.
