Detection and Evaluation on the Spine Tracking Accuracy during Image-Guided Radiation Therapy

Utilize the head and neck phantom, lung phantom and simulated human phantom to detect the spine tracking accuracy of Cyber Knife during IGRT, and give evaluation. Use CT to scan the head and neck phantom, lung phantom and simulated human phantom which have films set in, then make use of the treatment planning system to design plans for tracking cervical vertebra, thoracic vertebra, lumbar vertebra, caudal vertebra and thigh bone. Cyber Knife carries out the plans for phantoms, and E2E software is used to analyze the irradiating accuracy. Results The accuracy of tracking cervical vertebra was 0.54 mm and 0.68 mm, thoracic vertebra, 0.50 mm and 0.65 mm, lumbar vertebra, 0.70 mm, sacral vertebrae, 1.99 mm, ilium, 2.21 mm, thigh bone, 2.05 mm. For these 3 static phantoms, the accuracy of tracking cervical vertebra, thoracic vertebra and lumbar vertebra all reached the sub millimeter level, and the tracking accuracy of sacral vertebrae, ilium and thigh bone was 2±0.21 mm. So the spine tracking accuracy is quite good.