The respiratory gating radiotherapy technique is especially useful for
tumors that move, such as those in lung and liver cancer. CGMH introduces
the Real-time Position Management TM (RPM) respiratory gating system,
which gates the beam delivery during treatment to account for organ
motion. Information about tumor movement can be realized by using an
infrared camera to detect the patient breathing in and out during
treatment; then the respiratory gating signal can trigger the linac
accelerator x-ray beam to treat the tumor within the gated phase to assure
the accuracy of treatment position. A non-invasive marker box is placed on
the patient’s body and the infrared system tracks the chest wall’s movement
during the CT imaging. The big bore CT simulator with four-dimensional CT
capability provides the correlation of respiratory phase and tumor location
with a dynamic time frame. During the treatment, the radiation beam is
gated to when the target falls within the treatment field while avoiding
critical organs. In this case, we can treat patients with high accuracy while
minimizing treatment errors, and the patient can breathe normally and
remain comfortable and with high compliance during the treatment. This
technique takes about five to ten minutes more than regular treatment
time.
Video introduction