Stereotactic Body Radiation Therapy

Question: I heard Stereotactic Body Radiation Therapy means fewer radiation treatments for cancer patients. How does this work and when is it most appropriate?

Answer: Stereotactic body radiation therapy (SBRT) is a type of radiation therapy in which intense radiation doses are targeted precisely to the tumor while minimizing exposure to surrounding normal tissues and organs. Treatments range from one to five sessions.

With SBRT, the tumor is first visualized using high resolution diagnostic medical imaging such as CT scan or MRI. To ensure accuracy during treatment, a patient is placed in an immobilization device. A specialized CT scan is performed to obtain precise coordinates of the tumor’s location within the patient’s body. Then, a radiation treatment plan is made. During treatment, the position of the patient and tumor are confirmed with additional medical imaging to ensure accuracy.

The intensity of SBRT has shown some advantages in tumor control compared to traditional radiation therapy techniques. It appears to be effective in treating certain tumors that appear to be resistant to lower daily doses of radiation. Also, its precision can sometimes allow treatment in areas that have already been previously irradiated. SBRT is commonly used to treat early stage lung cancers in patients who cannot tolerate surgery, as well as some tumors in the liver, near the spine, and in the adrenal glands. Other sites are also being evaluated, and there is significant interest is using SBRT to shorten treatment times in prostate cancer.

Most cancers still require larger radiation fields to cover at-risk areas with treatment delivered over several weeks. However, in appropriate cases SBRT is an excellent alternative, offering a shorter and often more effective treatment course.