• The Journal of the Korean bone and joint tumor society
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• v.13 no.1
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• pp.14-21
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• 2007

Bone is a common site for metastatic spread from many kinds of malignancies. The morbidity associated with this metastatic spread can be significant, including severe pain. When it comes to spinal metastasis, occupying nearly 40% of skeletal metastases, the risks of complications, such as vertebral body collapse, nerve root impingement, or spinal cord compression, are also significant. Because of the necessity of preserving the integrity of the spinal column and the proximity of critical structures, surgical treatment has limitations when durable local control is desired. Radiotherapy, therefore, is often used as an adjunct treatment or as a sole treatment. A considerable limitation of standard radiotherapy is the reported recurrence rate or ineffective palliation of pain, either clinically or symptomatically. This may be due to limited radiation doses to tumor itself because of the proximity of critical structures. CyberKnife is an image-guided robotic radiosurgical system. The image guidance system includes a kilovoltage X-ray imaging source and amorphous silica detectors. The radiation delivery device is a mobile X-band linear accelerator (6 MV) mounted on a robotic arm. Highly conformal fields and hypofractionated radiotherapy schedules are increasingly being used as a means to achieve biologic dose escalation for body tumors. Therefore, we can give much higher doses to the targeted tumor volume with minimizing doses to the surrounding critical structures, resulting in more effective local control and less severe side effects, compared to conventional fractionated radiotherapy. A description of this technology and a review of clinical applications to bone metastases are detailed herein.

• Progress in Medical Physics
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• v.25 no.4
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• pp.264-270
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• 2014

This study developed a portable respiratory training device to improve breathing stability, which is an important element in using the CyberKnife Synchrony respiratory tracking device, one of the typical Stereotactic Radiation Therapy (SRT) devices. It produced an interface for users to be able to select one of two displays, a graph type and a bar type, supported an auditory system that helps them expect next respiration by improving a sense of rhythm of their respiratory period, and provided comfortable respiratory inducement. By targeting 5 applicants and applying individual respiratory period detected through a self-developed program, it acquired signal data of 'guide respiration' that induces breathing through signal data gained from 'free respiration' and an auditory system, and evaluated the usability by comparing deviation average values of respiratory period and respiratory amplitude. It could be identified that respiratory period decreased $55.74{\pm}0.14%$ compared to free respiration, and respiratory amplitude decreased $28.12{\pm}0.10%$ compared to free respiration, which confirmed the consistency and stability of respiratory. SBRT, developed based on these results, using the portable respiratory training device, for liver cancer or lung cancer, is evaluated to be able to help reduce delayed treatment time due to respiratory instability and improve treatment accuracy, and if it could be applied to developing respiratory training applications targeting an android-based portable device in the future, even use convenience and economic efficiency are expected.