Radiation Therapy for Soft Tissue Sarcomas
Radiation therapy uses high-energy rays (such as x-rays) or particles to kill cancer cells.
Most of the time radiation is given after surgery as an added measure. This is called adjuvant treatment and it is done to kill any cancer cells that may be left behind after surgery.
Radiation may also be used before surgery to shrink the tumor and make the operation easier. This is called neoadjuvant treatment.
Radiation can be the main treatment for sarcoma in someone whose general health is too poor to undergo surgery.
Radiation therapy can also be used to help symptoms of sarcoma when it has spread. This is called palliative treatment.
Types of radiation therapy
External beam radiation therapy: For this treatment, radiation delivered from outside the body is focused on the cancer. This is the type of radiation therapy most often used to treat sarcomas. Treatments are often given daily, 5 days a week, usually for several weeks. Often a technique called intensity modulated radiation therapy (IMRT) is used. This better focuses the radiation on the cancer and lessens the impact on healthy tissue.
In some centers, proton beam radiation is an option. This uses streams of protons instead of x-ray beams to treat the cancer. Although this has some advantages over IMRT in theory, it hasn’t been proven to be a better treatment for soft tissue sarcoma. Proton beam therapy is not widely available.
Intraoperative radiation therapy (IORT): This is a type of external beam radiation that is available in only a few centers. For this treatment, one large dose of radiation is given in the operating room after the tumor is removed but before the wound is closed. Giving radiation this way means that it doesn’t have to travel through healthy tissue to get to the area that needs to be treated. It also allows nearby healthy areas to be shielded more easily from the radiation. Often, IORT is only one part of radiation therapy, and the patient receives some other type of radiation after surgery.
Brachytherapy: Brachytherapy (sometimes called internal radiation therapy) is a treatment that places small pellets (or seeds) of radioactive material in or near the cancer. For soft tissue sarcoma, these pellets are put into catheters (very thin tubes) that have been placed during surgery. In high-dose rate (HDR) brachytherapy, the pellets give off a lot of radiation in a short time, and so stay in place for only minutes at a time. In low-dose rate (LDR) brachytherapy, the pellets may stay in place for days at a time, and are then removed.
Brachytherapy may be the only form of radiation therapy used or it can be combined with external beam radiation.
Side effects of radiation treatment
Side effects of radiation therapy depend on which area is treated and the dose given. Common side effects include
- Skin changes in the area the radiation went through the skin, which can range from redness to blistering and peeling
- Nausea and vomiting (more common with radiation to the abdomen)
- Diarrhea (most common with radiation to the pelvis and abdomen)
- Pain with swallowing (from radiation to the head, neck, or chest)
- Lung damage leading to problems breathing (from radiation to the chest)
- Bone weakness, which can lead to fracture years later
Radiation of large areas of an arm or leg can cause swelling, pain, and weakness in that limb.
Side effects of radiation therapy to the brain for metastatic sarcoma include hair loss, headaches, and problems thinking.
If given before surgery, radiation may cause problems with wound healing.
Many side effects improve or even go away some time after radiation is finished. Some though, like bone weakness and lung damage, can be permanent.
More information on this topic can be found in the Radiation section of our website, or in Understanding Radiation Therapy: A Guide for Patients and Families.
Last Medical Review: December 29, 2014 Last Revised: February 9, 2016