A fellow of the American College of Radiology, Dr. Alan H. Porter is the director of Porter Radiation Oncology, a radiology oncology center in Sarasota, Florida. Alan Porter, MD, is facile with advanced cancer treatments including stereotactic radiotherapy.
Stereotactic body radiotherapy (SBRT), also called stereotactic ablative radiotherapy (SABR), is an advanced type of tomotherapy that treats tumors in the body (excluding the central nervous system). The procedure channels a high dose of radiation to tumors from different angles and is often indicated for small early-stage tumors. With the aid of imaging tools such as CT and MRI, the position of the tumor(s) in the body is precisely mapped to ensure that only cells of the tumor are exposed to the high doses of the radiation beam. Normal tissues around the tumor receive a much lower dose than with other radiation treatments, which minimizes the risk of side effects.
The information that controls how cells reproduce is stored in their DNA. Generally, cancers occur in tissues that contain cells that carry a damaged version of such information. With stereotactic radiotherapy, the compromised DNA in each tumor cell is exposed to a level of radiation that damages the DNA further and turns off most of its features, including the ability to form another copy. This stops defective tumor cells from multiplying, which stops the growth of the tumor and results in its shrinkage.