Stereotactic Body Radiation Therapy (SBRT)
Stereotactic Body Radiation Therapy (SBRT), also known as stereotactic ablative radiotherapy (SABR), administers a very high dose of radiation, using several beams aimed at different angles to precisely target the tumor. This means the cancer gets a high dose of radiation, but the healthy surrounding tissues are spared. SBRT is typically used to treat small cancers, in the chest, abdomen and pelvis areas.
SBRT requires high positional accuracy. AlignRT® is useful to help more accurately position you for treatment, as well as ensure your position does not change during beam delivery. With AlignRT® you can be tracked in real time, and radiation can be stopped if you move out of position.
Breath hold techniques are often used along with AlignRT®
In some cases, breathing movement can be a concern, particularly when treating tumors in the chest and abdomen area. Because the treatment is so precise, your natural breath movement may move you out of the planned treatment position. Your oncologists may use breath hold to help establish the correct position. You will be asked to hold your breath for 20 seconds. While you hold your breath, the radiation is delivered. It is important that the breath hold is at the same level each day to make sure the treatment is reproducibly delivered in the same way it has been planned.
In some centers, a small screen will be displayed above your head to guide you to the correct position. This is called a Real Time Coach™ display.
The Real Time Coach™ Display, will provide you with a simple, clear display to show your breathing motion. When it is time for the radiation treatment to begin, the therapist will communicate with you over the intercom system. They will ask you to take a breath and hold it in. You will take a breath in until the line is in the center of the bar, and it will turn green when you are in the correct position. Only once this bar is green will the Radiation treatment begin. If at any time, you change your breath hold, the beam will be interrupted, and Radiation paused until you breathe again into the correct position. This allows you to control your breath hold during treatment.
AlignRT®+ DIBH, or other breath hold techniques, is an approach many centers are starting to use that will help ensure the most accurate treatment1.
1 Heinzerling JH, et al. Use of 3d optical surface mapping for quantification of interfraction set up error and intrafraction motion during stereotactic body radiation therapy treatments of the lung and abdomen. International Journal of Radiation Oncology • Biology • Physics 2017;99 (2):E670.
