Dosimetry Study of High Dose Rate Flattening Filter-Free Radiation on the Protection of Lumbosacral Spine and Pelvic Bone Marrow
Xiufeng Cong1
Jun Chen1
Xiaoting Zhang1
Zaiming Lu2
1.Department of Clinical Oncology, Shengjing Hospital of China Medical University, Shenyang 110042 Liaoning China2.Department of radiology, Shengjing Hospital of China Medical University
摘要：Objective This study aimed to analyze the dosimetric parameters of volumetric modulated arc therapy (VMAT) and dynamic multileaf collimator (DMLC) plans with lumbosacral spine (LS) and pelvic bone marrow (PBM) sparing in the flattening filter-free (FFF) model. Methods Thirty patients with cervical cancer were selected for analysis. For each pa-tient, four plans with different strategies were generated: VMAT_FF, VMAT_FFF, DMLC_FF, and DMLC_FFF. Dose volumes for organs at risk, conformity index, heterogeneity index (HI), and total number of machine unit (MU) were compared by paired t-test. Result Compared with plans in the FF model, the irradiated dose to LS significantly decreased both VMAT_FFF and DMLC_FFF plans in the FFF model while the MU increased. The mean dose of LS decreased by 107. 2 cGy (P<0. 05) in the VMAT_FFF plan. In comparison with the VMAT plans in both models of FF and FFF, the DM-LC plans reduced the dose volume of 10 Gy by 5. 9％ (P<0. 05), and the mean dose of LS was 189. 6-293. 1 cGy. The PBM volume receiving 40 Gy showed a decrease of 0. 5％ -1. 1％ (P<0. 05) as well. The HI increased in the VMAT plans by ap-proximately 0. 053 and 0. 039. Conclusion The DMLC plans exhibited the best sparing of the PBM and LS in both FF and FFF models and increased the HI. The plans in the FFF model could limit the volume dose of LS but increase the MU.
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论文发表日期：2020-03-30
在线出版日期：2025-08-15（本平台首次上网日期，不代表文献的发表时间）
页数：7( 9-15 )
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