放射治疗是II级胶质瘤的重要术后治疗方法。然而,目前尚缺乏对II级胶质瘤不同放疗计划的比较剂量学研究。因此,我们进行了这个病例系列分析,以比较螺旋断层疗法(TOMO)之间的剂量学差异,体积调制电弧治疗(VMAT),和II级胶质瘤的调强放疗(IMRT)。要做到这一点,7例诊断为II级胶质瘤的术后患者通过计算机断层扫描进行分析,然后计划使用TOMO,VMAT,IMRT。计划目标体积(PTV)规定剂量为50Gy(每日2.0Gy,5天/周)。通过监测单位(MU)评分来测量预期的治疗效率。比较患者的治疗计划中目标体积剂量覆盖率的质量,剂量输送的效率,和正常邻近危险器官(OAR)的剂量暴露。通过利用非参数方差分析来测量每种方法中的差异。研究表明,TOMO的PTV-D98%(PTV体积的98%接受的剂量)明显高于VMAT和IMRT(50.30±0.13vs49.21±0.19,p=0.006;50.30±0.13vs49.78±0.18,p=0.014),而PTV-D2%(PTV体积的2%接受的剂量)没有差异。IMRT最好达到合格指数(CI),和TOMO产生有利的均匀性指数(HI)(两者的p<0.05)。VMAT的MU少于IMRT和TOMO(分别为294±19、572±24、317±97)。IMRT对晶状体和脑干实现了更好的保护。我们的病例系列研究表明,TOMO,VMAT,IMRT实现了相对较好的目标剂量覆盖,大多数OAR都受到了很好的保护。IMRT不逊于TOMO和VMAT,仍然非常适合治疗大多数II级胶质瘤患者。
Radiotherapy is an essential postoperative treatment for grade II gliomas. However, comparative dosimetric studies of different radiotherapy plans for grade II gliomas are still lacking. Therefore, we conducted this
case series analysis to compare the dosimetric differences among helical tomotherapy (TOMO), volumetric modulated arc therapy (
VMAT), and intensity-modulated radiotherapy (IMRT) for grade II gliomas. To achieve that, seven diagnosed postoperative patients with grade II gliomas were analyzed by computed tomography and then planned with TOMO, VMAT, and IMRT. The plan target volume (PTV) prescribed dose was 50 Gy (daily fraction of 2.0 Gy, 5 days/week). The expected treatment efficiency was measured by monitor units (MUs) scoring. Treatment plans of the patients were compared in the quality of target volumes dosage coverage, the efficiency of dosage delivery, and the dosage exposure of normal adjacent organs at risk (OAR). Differences in each method were measured by utilizing the Nonparametric ANOVA. The study shows that TOMO achieved a significantly higher PTV-D98% (doses received by 98% of the PTV volume) than
VMAT and IMRT (50.30 ± 0.13 vs 49.21 ± 0.19, p = 0.006; 50.30 ± 0.13 vs 49.78 ± 0.18, p = 0.014), while there was no difference in PTV-D2% (doses received by 2% of the PTV volume). IMRT achieved a conformity index (CI) preferably, and TOMO generated a favorable homogeneity index (HI) (p < 0.05 for both). The MUs were fewer for
VMAT than IMRT and TOMO (294 ± 19, 572 ± 24, 317 ± 97, respectively). IMRT achieved better protection for the lens and brain stems. Our
case series study indicated that TOMO,
VMAT, and IMRT achieved a comparatively good target dosimetric coverage, and most OARs were protected well. IMRT is not inferior to TOMO and VMAT and is still very suitable for treating most grade II glioma patients.