Radiation therapy uses high energy x-rays to destroy cancer cells. Special tools and dosing will help to kill as much of the cancer as possible while minimizing the effect on nearby healthy tissue. A radiation oncologist will customize the treatment dose for individual needs.
For stomach cancer, radiation therapy is most often used in combination with chemotherapy (called chemoradiation). The combination of chemotherapy and radiation is more effective in shrinking the stomach tumor and extending life than either treatment alone.
Radiation therapy may also be given:
- Before surgery to shrink the tumor and minimize the amount of tissue that has to be removed
- After surgery to kill any remaining cancerous tissue
- For metastatic cancer to relieve symptoms and extend survival time
External Beam Radiation
In external beam radiation therapy, a machine directs high-energy rays through the body and into the tumor. There are many different radiation machines used for external radiation therapy based on the size and location of the tumor, surrounding tissue, and type of cancer. The radiation oncologist will discuss options, doses, and frequency of radiation so that the highest amount of radiation can be delivered to the cancer with as little impact on healthy tissue as possible. External beam radiation is often given daily over the course of several weeks.
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Delivery methods help to deliver the maximum amount of radiation possible to the tumor while minimizing exposure to healthy surrounding tissue. Methods to improve delivery include:
- 3D conformal radiation therapy (3D-CRT)—Imaging tests are used to map the abdomen. Once the tumor is located, radiation beams are directed at it from different angles.
- Intensity modulated radiation therapy (IMRT)—A computerized machine rotates around the patient to deliver radiation to the tumor site. Dosage can be weakened or strengthened depending on the target tissue. Another type of IMRT that can be used is called volumetric modulated arc therapy (VMAT).
This is also called internal radiation therapy. Radioactive material sealed in needles, seeds, wires, or catheters is placed near the tumor. This allows a higher dose of radiation to be delivered directly to the tumor.
A variety of treatments are available to help manage side effects of radiation therapy, such as dry, irritated skin, nausea, vomiting, diarrhea, and fatigue due to anemia. Sometimes adjustments to treatment doses may also be possible. The earlier side effects are addressed, the more likely they will be controlled with a minimum of discomfort.
Gastric carcinoma. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T116155/Gastric-carcinoma. Updated September 27, 2016. Accessed September 1, 2017.
Gastric cancer. National Cancer Institute website. Available at: https://www.cancer.gov/types/stomach/patient/stomach-treatment-pdq. Updated April 27, 2017. Accessed September 1, 2017.
Radiation therapy for stomach cancer. American Cancer Society website. Available at: https://www.cancer.org/cancer/stomach-cancer/treating/radiation-therapy.html. Updated March 15, 2016. Accessed September 1, 2017.
Stomach cancer. Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/gastrointestinal-disorders/tumors-of-the-gi-tract/stomach-cancer. Updated January 2017. Accessed September 1, 2017.
Last reviewed September 2018 by EBSCO Medical Review Board Michael Woods, MD, FAAP Last Updated: 9/1/2017