TY - JOUR
T1 - Feasibility of deformation-independent tumor-tracking radiotherapy during respiration
AU - Kim, Seonkyu
AU - Yoon, Myonggeun
AU - Shin, Dong
AU - Kim, Dongwook
AU - Lee, Sangyeob
AU - Lee, Se
AU - Park, Sung
AU - Song, Sang
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/4
Y1 - 2011/4
N2 - To evaluate the feasibility of tumor-tracking radiotherapy that does not consider tumor deformation during respiration. Four-dimensional computed tomography (4D-CT) data, which considers 10 phases of the respiration cycle, were acquired in 4 patients with lung cancer and 4 patients with liver cancer. Initial treatment plans were established at the end of the inhalation phase (phase 1). As a simulation of deformation-free tumor-tracking radiotherapy, the beam center of the initial plan was moved to the tumor center for all other phases, and the tumor shape acquired from phase 1 was used for all 10 phases. The feasibility of this method was analyzed based on assessment of equivalent uniform dose (EUD), homogeneity index (HI) and coverage index (COV). In photon radiation treatment, movement-induced dose reduction was not particularly significant, with 0.5%, 17.3% and 2.8% average variation in EUD, HI and COV, respectively. In proton radiation treatment, movement-induced dose reduction was more significant, with 0.3%, 40.5% and 2.2% average variation in EUD, HI and COV, respectively. Proton treatment is more sensitive to tumor movement than is photon treatment, and that it is reasonable to disregard tumor deformation during photon therapy employing tumor-tracking radiotherapy.
AB - To evaluate the feasibility of tumor-tracking radiotherapy that does not consider tumor deformation during respiration. Four-dimensional computed tomography (4D-CT) data, which considers 10 phases of the respiration cycle, were acquired in 4 patients with lung cancer and 4 patients with liver cancer. Initial treatment plans were established at the end of the inhalation phase (phase 1). As a simulation of deformation-free tumor-tracking radiotherapy, the beam center of the initial plan was moved to the tumor center for all other phases, and the tumor shape acquired from phase 1 was used for all 10 phases. The feasibility of this method was analyzed based on assessment of equivalent uniform dose (EUD), homogeneity index (HI) and coverage index (COV). In photon radiation treatment, movement-induced dose reduction was not particularly significant, with 0.5%, 17.3% and 2.8% average variation in EUD, HI and COV, respectively. In proton radiation treatment, movement-induced dose reduction was more significant, with 0.3%, 40.5% and 2.2% average variation in EUD, HI and COV, respectively. Proton treatment is more sensitive to tumor movement than is photon treatment, and that it is reasonable to disregard tumor deformation during photon therapy employing tumor-tracking radiotherapy.
KW - 4D-CT
KW - Deformation
KW - real-time tumor tracking
KW - respiration
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U2 - 10.4103/0971-6203.79691
DO - 10.4103/0971-6203.79691
M3 - Article
C2 - 21731223
AN - SCOPUS:79955723004
VL - 36
SP - 78
EP - 84
JO - Journal of Medical Physics
JF - Journal of Medical Physics
SN - 0971-6203
IS - 2
ER -