AbstractObjective To figure out the optimal parameters of a volumetric modulated arc therapy (VMAT) plan for cervical and upper esophageal cancer by quality evaluation of VMAT plans with different parameters, and to provide a reference for the design of clinical VMAT treatment plan. Methods Ten patients with cervical esophageal cancer and ten patients with upper esophageal cancer were enrolled as subjects. The Nucletron Oncentra 4.3 treatment planning system was used to generate plans for Elekta Synergy VMAT accelerator. Six VMAT plans were made with variation in the gantry angle (2°, 3°, and 4°), the maximum delivery time (80 s, 110 s, and 150 s), and the collimator angle (0° and 45°). The doses to the planning target volume and organs at risk were analyzed by paired t test. Results For cervical and upper esophageal cancer, the quality of VMAT plans with a collimator angle of 45° was better than those with a collimator angle of 0°(P=0.003-0.007). For cervical esophageal cancer, there was no significant difference in quality between VMAT plans with a maximum delivery time of 110 s or 150 s and those with a maximum delivery time of 80 s (P>0.05);for upper esophageal cancer,there was also no significant difference in quality between VMAT plans with three different maximum delivery times (P>0.05). For cervical esophageal cancer, the VMAT plans with a gantry angle of 3° had a better quality than those with a gantry angle of 2° or 4°(P=0.010-0.048). For upper esophageal cancer, the VMAT plans with a gantry angle of 3°had a better quality than those with a gantry angle of 4°(P=0.010-0.048). Compared with those with a gantry angle of 2°, the VMAT plans with a gantry angle of 3°had a slightly better dose distribution in the target volume (P=0.046), but a slightly higher dose to lung tissue (V25 and V30,P=0.007 and 0.026). Conclusions The optimal initial parameters of a VMAT plan for cervical and upper esophageal cancer are a collimator angle of 45°, a maximum delivery time of 80 s, and a gantry angle of 3°.
Corresponding Authors:
Chi Zifeng,Email:chizf216@126.com
E-mail: chizf216@126.com
Cite this article:
Liu Dan,Zhang Ruohui,Jing Zhonghao et al. A study of parameters of a volumetric modulated arc therapy plan for cervical and upper esophageal cancer[J]. Chinese Journal of Radiation Oncology, 2016, 25(8): 862-866.
Liu Dan,Zhang Ruohui,Jing Zhonghao et al. A study of parameters of a volumetric modulated arc therapy plan for cervical and upper esophageal cancer[J]. Chinese Journal of Radiation Oncology, 2016, 25(8): 862-866.
[1] 陈婷婷,张西志,花威,等.容积旋转调强与固定野动态调强在上段食管癌治疗中的剂量学比较[J].临床肿瘤学杂志,2013,18(2):151-154.DOI:10.3969/j.issn.1009-0460.2013.02.014 Chen TT,Zhang XZ,Hua W,et al. Dosimetric comparison between Rapid Arc and fixed gantry dynamic IMRT for upper esophageal cancer[J].Chin Clin Oncol,2013,18(2):151-154.DOI:10.3969/j.issn.1009-0460.2013.02.014 [2] Li GJ,Zhang YJ,Jiang XQ,et al. Evaluation of the ArcCHECK QA system for IMRT and VMAT verification[J].Phys Med,2013,29(3):295-303.DOI:10.1016/j.ejmp.2012.04.005 [3] Zhu JH,Chen LX,Jin GH,et al. A comparison of VMAT dosimetric verifications between fixed and rotating gantry positions[J].Phys Med Biol,2013,58(5):1315-1322.DOI:10.1088/0031-9155/58/5/1315 [4] 王澜,高超,李晓宁,等.食管癌三维适形后程加速放疗的临床研究[J].中华放射肿瘤学杂志,2010,19(1):14-17.DOI:10.3760/cma.j.issn.1004-4221.2010.01.006 Wang L,Gao C,Li XN,et al. Late course accelerated three-dimensional conformal radiotherapy for esophageal carcinoma[J].Chin J Radiat Oncol,2010,19(1):14-17.DOI:10.3760/cma.j.issn.1004-4221.2010.01.006 [5] Oliver M,Gagne I,Popescu C,et al. Analysis of RapidArc optimization strategies using objective function values and dose-volume histograms[J].J Appl Clin Med Phys,2010,11(1):3114.DOI:10.1120/jacmp.v11i1.3114 [6] Otto K.Letter to the Editor on ‘Single-Arc IMRT？’[J].Phys Med Biol,2009,54(8):L37-L41.DOI:10.1088/0031-9155/54/8/L03 [7] Otto K.Volumetric modulated arc therapy:IMRT in a single gantry arc[J].Med Phys,2008,35(1):310-317.DOI:10.1118/1.2818738 [8] Bzdusek K,Friberger H,Eriksson K,et al. Development and evaluation of an efficient approach to volumetric arc therapy planning[J].Med Phys,2009,36(6):2328-2339.DOI:10.1118/1.3132234 [9] Eriksson K,Friberger H,Sterner E,et al. Volumetric modulated arc therapy (VMAT) optimization with RayArc[M].Stockholm:RaySearch White Paper,2009:1-16 [10] Feygelman V,Zhang G G,Stevens C.Initial dosimetric evaluation of SmartArc—a novel VMAT treatment planning module implemented in a multi-vendor delivery chain[J].J Appl Clin Med Phys,2010,11(1):3169.DOI:10.1120/jacmp.v11i1.3169 [11] Yang K,Yan D,Tyagi N.Sensitivity analysis of physics and planning SmartArc parameters for single and partial arc VMAT planning[J].J Appl Clin Med Phys,2012,13(6):3760.DOI:10.1120/jacmp.v13i6.3760
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