TY - GEN
T1 - Effects of image lag on real-time target tracking in radiotherapy
AU - Tanaka, R.
AU - Ichikawa, K.
AU - Mori, S.
AU - Dobashi, S.
AU - Kumagaya, M.
AU - Kawashima, H.
AU - Morita, S.
AU - Sanada, S.
PY - 2010
Y1 - 2010
N2 - There is a concern that image lag may reduce accuracy of real-time target tracking in radiotherapy. This study was performed to investigate influence of image lag on the accuracy of target tracking in radiotherapy. Fluoroscopic image: were obtained using a direct type of dynamic flat-panel detector (FPD) system under conditions of target tracking during radiotherapy. The images continued to be read out after X-irradiations and cutoff, and image lag properties in the system were then determined. Subsequently, a tungsten materials plate with a precision edge was mounted on to a motor control device, which provided a constant velocity. The plate was moved into the center of the detector at movement rate of 1 and 20 mm/s, covering lung tumor movement of normal breathing, and MTF and profile curves were measured on the edges covering and uncovering the detector. A lung tumor with blurred edge due to image lag was simulated using the results and then superimposed on breathing chest radiographs of a patient. The moving target with and without image lag was traced using a template-matching technique. In the results, the target could be traced within a margin for error ii external radiotherapy. The results indicated that there was no effect of image lag on target tracking in usual breathing speed in a radiotherapy situation. Further studies are required to investigate influence by the other factors, such a: exposure dose, target size and shape, imaging rate, and thickness of a patient's body.
AB - There is a concern that image lag may reduce accuracy of real-time target tracking in radiotherapy. This study was performed to investigate influence of image lag on the accuracy of target tracking in radiotherapy. Fluoroscopic image: were obtained using a direct type of dynamic flat-panel detector (FPD) system under conditions of target tracking during radiotherapy. The images continued to be read out after X-irradiations and cutoff, and image lag properties in the system were then determined. Subsequently, a tungsten materials plate with a precision edge was mounted on to a motor control device, which provided a constant velocity. The plate was moved into the center of the detector at movement rate of 1 and 20 mm/s, covering lung tumor movement of normal breathing, and MTF and profile curves were measured on the edges covering and uncovering the detector. A lung tumor with blurred edge due to image lag was simulated using the results and then superimposed on breathing chest radiographs of a patient. The moving target with and without image lag was traced using a template-matching technique. In the results, the target could be traced within a margin for error ii external radiotherapy. The results indicated that there was no effect of image lag on target tracking in usual breathing speed in a radiotherapy situation. Further studies are required to investigate influence by the other factors, such a: exposure dose, target size and shape, imaging rate, and thickness of a patient's body.
KW - Flat panel detector
KW - Image lag
KW - Radiotherapy
KW - Target tracking
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U2 - 10.1117/12.844202
DO - 10.1117/12.844202
M3 - Conference contribution
AN - SCOPUS:84873930920
SN - 9780819480231
T3 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
BT - Medical Imaging 2010
T2 - Medical Imaging 2010: Physics of Medical Imaging
Y2 - 15 February 2010 through 18 February 2010
ER -