Active Breathing Coordinator
Active Breathing Coordinator™ (ABC) is one of the advanced radiation therapy technologies available at three Swedish Cancer Institute locations – Swedish/First Hill, Highline Medical Center and Swedish/Issaquah. ABC provides patients with left-sided breast cancer maximum protection from radiation to their hearts.
What is ABC?
ABC is a noninvasive, advanced technology that helps the patient hold her breath while she receives radiation therapy.
Why is this technology important?
In preparation for any radiation therapy, a radiation oncologist will use CT images of the tumor to prepare a customized treatment plan. The goal is to precisely target the entire tumor with the highest, most appropriate dose of radiation while limiting the amount of radiation the surrounding healthy tissue and organs receive.
Treating a moving target: Because even the slightest movement can change the location of the tumor, targeting a tumor that moves as the patient breathes may require a slightly larger radiation field to compensate for the tumor’s movement. Some healthy tissue may inadvertently receive radiation as the patient breathes and the tumor shifts.
Protecting the heart: With left-sided breast cancer, which moves when the patient breathes, the heart is part of the healthy tissue that needs to be protected. Studies have shown that patients who have received large doses of radiation to some parts of their hearts or who have had larges areas of the heart exposed to smaller doses of radiation have a higher risk of developing radiation-induced heart disease.
How does ABC work?
When Active Breathing Coordinator is used during radiation therapy, the patient takes a deep breath before the beam of radiation is delivered. This deep breath increases the distance between the area receiving radiation (the breast tissue or chest wall on the patient’s left side) and the heart. Increasing this distance means there is less risk the heart will receive any incidental radiation during treatment and, therefore, there is less risk of the patient developing radiation-induced heart disease.
The ABC process
The ABC process begins with a referral and consultation with a radiation oncologist. After the initial consultation, the process includes the following steps.
Planning: The patient is first scheduled for a planning/training appointment so CT images can be taken and the patient can become comfortable with the equipment and with holding her breath for a short period of time. As part of the planning/training appointment, the doctor and patient discuss the ABC procedure and determine the amount of time the patient will hold her breath. Usually a breath hold is just 20 to 25 seconds; however, the patient is always in control and can signal she wants to resume breathing at any time if she cannot hold her breath for that length of time.
A small clamp is placed on the patient’s nose to avoid accidental breathing through the nose. The patient also holds a mouthpiece, which is attached to a breathing tube, between her teeth. When the patient is ready, she takes a deep breath. When she has breathed in enough air to inflate her lungs to a pre-determined volume, she holds her breath. A small valve in the breathing tube closes so no additional air can enter her lungs during the breath hold. This stops any movement. A clock in the treatment room allows the patient to see the time remaining. If at any time the patient wants to take a breath, she releases pressure on a switch and the valve automatically opens so she can breathe.
Using ABC while taking CT images provides a clearer image – not blurred by movement – and the edges of the tumor are more crisply defined.
The radiation oncologist uses these images to develop the patient’s personalized treatment plan. The images also are used to ensure the patient is positioned exactly the same during each treatment appointment.
Treatment: On the day of treatment, the patient follows the same routine as she did during the planning appointment. Once the nose clamp and mouthpiece are in place, treatment begins. When the patient holds her breath, the radiation therapist administers a beam of radiation to the pre-determined target area. Typically the deep-breath hold procedure is repeated four to six times during each treatment.
Where is ABC available?
ABC is available at the following three Swedish Cancer Institute locations: