Department of Radiation Oncology and Research Institute, Pusan National University Yangsan Hospital and Pusan National University School of Medicine, Yangsan, South Korea , apex7171@hanmail.net
Abstract: (15 Views)
Background: Deep-inspiration breath-hold (DIBH) is a helpful technique during radiation therapy (RT) for breast cancer that can protect vital organs and deliver a more accurate treatment dose to the target. A laser sensor-based position monitoring system is developed to measure the absolute position of an object and achieve high accuracy and reproducibility during DIBH. Materials and Methods: A laser distance sensor (LDS) was fabricated to be mounted on a commercially available breast board and configured to provide real-time monitoring to assist with respiratory control. DIBH was measured in 10 volunteers with and without self-monitoring. Using an anthropomorphic phantom, we calculated the change in dose distribution due to DIBH error. We estimated the change in dose to target, the heart, and left lung due to DIBH error from the volunteer data. Results: With monitoring, the DIBH error was within 2 mm; without monitoring, the DIBH error increased to approximately 5 mm. Some of the volunteers who did not perform self-monitoring had large DIBH errors. This resulted in suboptimal dose distributions to the target, heart, and left lung, due to unintended alterations in the intended dose distribution. Conclusion: A self-monitoring system using LDS can greatly assist in the reproducibility of DIBH, thus helping to maintain the planned prescribed dose.