The Active Breathing Coordinator (ABC) allows for temporary and reproducible immobilization of internal thoracic structures by monitoring the patient's breathing cycle and implementing a breath hold at a predefined lung volume level. While ABC is FDA approved and commercially available, only preliminary dosimetric data is available on a small number of patients with breast cancer. There is some data using ABC for intrathoracic malignancies, which shows that it is feasible and safe to use. ABC can be used to optimize the distance between chest wall, heart and liver. This allows adequate treatment of the breast and underlying chest wall while minimizing irradiated cardiac and liver volume.
