TY - JOUR
T1 - Multiple-CT optimization
T2 - An adaptive optimization method to account for anatomical changes in intensity-modulated proton therapy for head and neck cancers
AU - Yang, Zhiyong
AU - Zhang, Xiaodong
AU - Wang, Xianliang
AU - Zhu, X. Ronald
AU - Gunn, Brandon
AU - Frank, Steven J.
AU - Chang, Yu
AU - Li, Qin
AU - Yang, Kunyu
AU - Wu, Gang
AU - Liao, Li
AU - Li, Yupeng
AU - Chen, Mei
AU - Li, Heng
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2020/1
Y1 - 2020/1
N2 - Purpose: We aimed to determine whether multiple-CT (MCT) optimization of intensity-modulated proton therapy (IMPT) could improve plan robustness to anatomical changes and therefore reduce the additional need for adaptive planning. Methods and materials: Ten patients with head and neck cancer who underwent IMPT were included in this retrospective study. Each patient had primary planning CT (PCT), a first adaptive planning CT (ACT1), and a second adaptive planning CT (ACT2). Selective robust IMPT plans were generated using each CT data set (PCT, ACT1, and ACT2). Moreover, a MCT optimized plan was generated using the PCT and ACT1 data sets together. Dose distributions optimized using each of the four plans (PCT, ACT1, ACT2, and MCT plans) were re-calculated on ACT2 data. The doses to the target and to organs at risk were compared between optimization strategies. Results: MCT plans for all patients met all target dose and organs-at-risk criteria for all three CT data sets. Target dose and organs-at-risk dose for PCT and ACT1 plans re-calculated on ACT2 data set were compromised, indicating the need for adaptive planning on ACT2 if PCT or ACT1 plans were used. The D98% of CTV1 and CTV3 of MCT plan re-calculated on ACT2 were both above the coverage criteria. The CTV2 coverage of the MCT plan re-calculated on ACT2 was worse than ACT2 plan. The MCT plan re-calculated on ACT2 data set had lower chiasm, esophagus, and larynx doses than did PCT, ACT1, or ACT2 plans re-calculated on ACT2 data set. Conclusions: MCT optimization can improve plan robustness toward anatomical change and may reduce the number of plan adaptation for head and neck cancers.
AB - Purpose: We aimed to determine whether multiple-CT (MCT) optimization of intensity-modulated proton therapy (IMPT) could improve plan robustness to anatomical changes and therefore reduce the additional need for adaptive planning. Methods and materials: Ten patients with head and neck cancer who underwent IMPT were included in this retrospective study. Each patient had primary planning CT (PCT), a first adaptive planning CT (ACT1), and a second adaptive planning CT (ACT2). Selective robust IMPT plans were generated using each CT data set (PCT, ACT1, and ACT2). Moreover, a MCT optimized plan was generated using the PCT and ACT1 data sets together. Dose distributions optimized using each of the four plans (PCT, ACT1, ACT2, and MCT plans) were re-calculated on ACT2 data. The doses to the target and to organs at risk were compared between optimization strategies. Results: MCT plans for all patients met all target dose and organs-at-risk criteria for all three CT data sets. Target dose and organs-at-risk dose for PCT and ACT1 plans re-calculated on ACT2 data set were compromised, indicating the need for adaptive planning on ACT2 if PCT or ACT1 plans were used. The D98% of CTV1 and CTV3 of MCT plan re-calculated on ACT2 were both above the coverage criteria. The CTV2 coverage of the MCT plan re-calculated on ACT2 was worse than ACT2 plan. The MCT plan re-calculated on ACT2 data set had lower chiasm, esophagus, and larynx doses than did PCT, ACT1, or ACT2 plans re-calculated on ACT2 data set. Conclusions: MCT optimization can improve plan robustness toward anatomical change and may reduce the number of plan adaptation for head and neck cancers.
KW - Adaptive planning
KW - Head and neck cancer
KW - Intensity-modulated proton therapy
KW - Multiple CT optimization
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U2 - 10.1016/j.radonc.2019.09.010
DO - 10.1016/j.radonc.2019.09.010
M3 - Article
C2 - 31564553
AN - SCOPUS:85072621550
SN - 0167-8140
VL - 142
SP - 124
EP - 132
JO - Radiotherapy and Oncology
JF - Radiotherapy and Oncology
ER -