Yuan Jun, Lei Mingjun, Yang Zhen, Fu Jun, Huo Lei, Hong Jidong
Department of Radiation Oncology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
The Institute of Skull Base Surgery and Neuro-Oncology at Hunan, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
Mol Clin Oncol. 2016 Jul;5(1):181-188. doi: 10.3892/mco.2016.872. Epub 2016 Apr 22.
The aim of the present study was to evaluate the difference in treatment plan quality, monitor units (MUs) per fraction and dosimetric parameters between IMRT (intensity-modulated radiotherapy) and RapidArc with single arc (RA1) and dual arc (RA2) for malignant glioma involving the parietal lobe. Treatment plans for IMRT and RA1 and RA2 were prepared for 10 patients with malignant gliomas involving the parietal lobe. The Wilcoxon matched-pair signed-rank test was used to compare the plan quality, monitor units and dosimetric parameters between IMRT and RA1 and RA2 through dose-volume histograms. Dnear-max (D2%) to the left lens, right lens and left optical nerve in RA1 were less compared with those in IMRT; D2% to the right lens and right optic nerve in RA2 were less compared with those in IMRT. D2% to the optic chiasma in RA2 was small compared with that in RA1. The median dose (D50%) to the right lens and right optic nerve in RA1 and RA2 was less compared with the identical parameters in IMRT, and D50% to the brain stem in RA2 was less compared with that in RA1. The volume receiving at least 45 Gy (V45) or V50 in normal brain tissue (whole brain minus the planning target volume 2; B-P) in RA1 was less compared with that in IMRT. V30, V35, V40, V45, or V50 in B-P in RA2 was less compared with that in IMRT. The MUs per fraction in RA1 and RA2 were significantly less compared with those in IMRT. All differences with a P-value<0.05 were considered to be significantly different. In conclusion, RA1 and RA2 markedly reduced the MUs per fraction, and spared partial organs at risk and B-P compared with IMRT.
本研究的目的是评估调强放射治疗（IMRT）与单弧（RA1）和双弧（RapidArc，RA2）容积旋转调强放疗在治疗累及顶叶的恶性胶质瘤时，治疗计划质量、每分次监测单位（MUs）和剂量学参数的差异。为10例累及顶叶的恶性胶质瘤患者制定了IMRT、RA1和RA2的治疗计划。通过剂量体积直方图，采用Wilcoxon配对符号秩检验比较IMRT与RA1和RA2之间的计划质量、监测单位和剂量学参数。与IMRT相比，RA1中左侧晶状体、右侧晶状体和左侧视神经的Dnear-max（D2%）较低；与IMRT相比，RA2中右侧晶状体和右侧视神经的D2%较低。与RA1相比，RA2中视交叉的D2%较小。与IMRT中的相同参数相比，RA1和RA2中右侧晶状体和右侧视神经的中位剂量（D50%）较低，与RA1相比，RA2中脑干的D50%较低。与IMRT相比，RA1中正常脑组织（全脑减去计划靶体积2；B-P）中接受至少45 Gy（V45）或V50的体积较小。与IMRT相比，RA2中B-P的V30、V35、V40、V45或V50较小。与IMRT相比，RA1和RA2的每分次MUs显著减少。所有P值<0.05的差异均被认为具有显著差异。总之，与IMRT相比，RA1和RA2显著减少了每分次MUs，并使部分危及器官和B-P得到了保护。
