论文部分内容阅读
Objective The aiom of the study was to compare the impacts of two types of multileaf collimators(MLC) [standard MLC with a width of 10 mm(s MLC) and micro-MLC with a width of 5 mm(m MLC)] on volumetric modulated arc therapy(VMAT) planning for malignant pleural mesothelioma. Methods VMAT for ten patients with inoperable malignant pleural mesotheliomas was retrospectively planned with the s MLC and m MLC. Histogram-based dose-volume parameters of the planning target volume(PTV) [conformity index(CI) and homogeneous index(HI)] and organs-at-risk were compared for VMAT plans with s MLC(s MLC-VMAT) and m MLC(m MLC-VMAT). Results The m MLC-VMAT plans were more efficient(average delivery time: 2.67±1.49 min) than the s MLC-VMAT plans(average delivery time: 4.21 ± 2.03 min; P < 0.05). Moreover, compared to the s MLC plans, the m MLC plans demonstrated advantages in the dose coverage of the PTV(CI 0.75 ± 0.08 vs 0.73 ± 0.09; HI 1.09 ± 0.02 vs 1.10 ± 0.02), although the difference was not statistically significant(P > 0.05). In addition, significant dose sparing in the fraction of the ipsilateral lung volume receiving > 20 Gy(V20; 54.72 ± 27.08 vs 58.52 ± 29.30) and > 30 Gy(V30; 42.74 ± 27.86 vs 46.86 ± 31.49) radiation, respectively, was observed for the m MLC plans(P < 0.05). Conclusion Comparing s MLC-VMAT and m MLC-VMAT not only demonstrated the higher efficiency and better optimal target coverage of m MLC-VMAT, but also considerably improved the dose sparing of the ipsilateral lung in the VMAT plans for malignant pleural mesothelioma.
Objective The aiom of the study was to compare the impacts of two types of multileaf collimators (MLC) [standard MLC with a width of 10 mm (s MLC) and micro-MLC with a width of 5 mm (m MLC)] on volumetric modulated VM therapy for VMT for ten patients with malignant pleural mesotheliomas was retrospectively planned with the MLC and m MLC. Histogram-based dose-volume parameters of the planning target volume (PTV) [conformity Results The m MLC-VMAT plans were more for VMAT plans with s MLC (s MLC-VMAT) and m MLC (m MLC-VMAT). Results The m MLC-VMAT plans were more MLC plans characterized advantages in the (average delivery time: 2.67 ± 1.49 min) than the MLC-VMAT plans (average delivery time: 4.21 ± 2.03 min; P <0.05) dose coverage of the PTV (CI 0.75 ± 0.08 vs 0.73 ± 0.09; HI 1.09 ± 0.02 vs 1.10 ± 0.02), although the difference was not Significant spiking in the fraction of the ipsilateral lung volume receiving> 20 Gy (V20; 54.72 ± 27.08 vs 58.52 ± 29.30) and> 30 Gy (V30; 42.74 ± 27.86 vs 46.86 ± 31.49) radiation, respectively, was observed for the m MLC plans (P <0.05). Conclusion Comparing s MLC-VMAT and m MLC-VMAT not only demonstrated the higher efficiency and better optimal target coverage of m MLC-VMAT, but also improved the dose sparing of the ipsilateral lung in the VMAT plans for malignant pleural mesothelioma.