TY - JOUR
T1 - A method incorporating 4DCT data for evaluating the dosimetric effects of respiratory motion in single-arc IMAT
AU - Kuo, H. C.
AU - Mah, D.
AU - Chuang, K. S.
AU - Wu, A.
AU - Hong, L.
AU - Yaparpalvi, R.
AU - Spierer, M.
AU - Kalnicki, S.
PY - 2010
Y1 - 2010
N2 - This study introduces a method incorporating 4DCT data to determine the impact of respiratory motion in single-arc intensity-modulated arc therapy (IMAT). Simulation was done by re-warping the static dose distribution of all phases of a 4DCT image set with a 3D deformation map to reference CT images at end-inspiration and end-expiration. To calculate the dose received during respiration under IMAT, the control points were interpolated and re-distributed into separate IMAT plans corresponding to each respiratory phase. This study also investigated the role that plan complexity may play in the dosimetric impact of the respiratory motion in the delivery of IMAT. The dosimetric impact of organ motion was evaluated by analyzing the degradation of D95, D50 and D05 of the CTV and PTV. From the results shown for the patients in this study who had maximum organ motion displacement ∼15 mm, the dosimetric impact is rather small. Therefore, our preliminary results suggest that respiratory motion of less than 1.5 cm may be ignored for both moderately and highly modulated IMAT, irrespective of the number of fractions. Specifically, highly modulated plans only increased the degradation of D 95 of the DVH curves for a single fraction by 2% in the CTV and 9% in the PTV compared to the expected value of the multi-fraction plan.
AB - This study introduces a method incorporating 4DCT data to determine the impact of respiratory motion in single-arc intensity-modulated arc therapy (IMAT). Simulation was done by re-warping the static dose distribution of all phases of a 4DCT image set with a 3D deformation map to reference CT images at end-inspiration and end-expiration. To calculate the dose received during respiration under IMAT, the control points were interpolated and re-distributed into separate IMAT plans corresponding to each respiratory phase. This study also investigated the role that plan complexity may play in the dosimetric impact of the respiratory motion in the delivery of IMAT. The dosimetric impact of organ motion was evaluated by analyzing the degradation of D95, D50 and D05 of the CTV and PTV. From the results shown for the patients in this study who had maximum organ motion displacement ∼15 mm, the dosimetric impact is rather small. Therefore, our preliminary results suggest that respiratory motion of less than 1.5 cm may be ignored for both moderately and highly modulated IMAT, irrespective of the number of fractions. Specifically, highly modulated plans only increased the degradation of D 95 of the DVH curves for a single fraction by 2% in the CTV and 9% in the PTV compared to the expected value of the multi-fraction plan.
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U2 - 10.1088/0031-9155/55/12/014
DO - 10.1088/0031-9155/55/12/014
M3 - Article
C2 - 20508324
AN - SCOPUS:77954168302
SN - 0031-9155
VL - 55
SP - 3479
EP - 3497
JO - Physics in Medicine and Biology
JF - Physics in Medicine and Biology
IS - 12
ER -