Department of Radiation Oncology, National University Health System, Singapore.
Department of Radiation Oncology, National University Health System, Singapore.
J Med Imaging Radiat Sci. 2023 Mar;54(1):167-177. doi: 10.1016/j.jmir.2022.10.195. Epub 2022 Nov 29.
Previous non-randomised studies comparing dosimetric outcomes between advanced techniques such as IMRT and VMAT reported conflicting findings. We thus sought to perform a systematic review and meta-analysis to consolidate the findings of these studies.
We searched PUBMED and EMBASE for eligible studies from their time of inception to 10 March 2022. A random effects model was used to estimate the pooled mean differences (MDs) and their 95% confidence intervals(CIs) for target volume coverage, organ-at-risk(OAR) doses, monitor units(MUs) and treatment delivery times. We also performed a subgroup analysis to evaluate if different treatment planning systems (TPS) (Eclipse, Monaco and Pinnacle) used affected the pooled mean differences.
A total of 17 studies (383 patients) were eligible to be included. The pooled results showed that dual arc VMAT reduced D2% of PTV (MD=0.71Gy,95%CI=0.14-1.27,P=0.01), mean left cochlea dose (MD=2.6Gy,95%CI=0.03-5.16,P=0.05), mean right cochlea dose (MD=3.4Gy,95%CI=0.7-6.1,P=0.01), MUs (MD=554.9,95%CI=245.8-863.9,P=0.0004), treatment delivery times (MD=6.7mins,95%CI=4.5-8.9,P<0.0001) and integral dose (MD=0.97Gy,95%CI=0.28-1.67,P=0.006). None of the other indices were significantly better for the IMRT plans. The subgroup analysis showed that the integral dose was significantly lower only for Eclipse (MD=0.88Gy, 95%CI=0.14-1.63, P=0.02). The total MUs was significantly lower only for Eclipse (MD=1035.2, 95%CI=624.6-1445.9, P<0.0001) and Pinnacle (MD=293, 95%CI=15.6-570.5, P=0.04). Similarly, delivery time was also significantly lower only for Eclipse (MD=6.1mins, 95%CI=5.7-6.5, P<0.0001) and Pinnacle (MD=4.9mins, 95%CI=2.6-7.2, P<0.0001). The subgroup analysis however showed that target coverage was superior for the IMRT plans for both Pinnacle (MD=0.48Gy, 95%CI=0.31-0.66, P<0.0001) and Monaco (MD=0.12Gy, 95%CI=0.07-0.17, P<0.0001).
Dual-arc VMAT plans improved OAR doses, MUs and treatment times as compared to IMRT plans. The different TPS used may modify dosimetric outcomes.
先前比较调强放疗（IMRT）和容积旋转调强放疗（VMAT）等先进技术的剂量学结果的非随机研究报告了相互矛盾的结果。因此，我们旨在进行系统评价和荟萃分析，以整合这些研究的结果。
我们从成立之初到 2022 年 3 月 10 日在 PUBMED 和 EMBASE 上搜索符合条件的研究。使用随机效应模型估计目标体积覆盖、危及器官（OAR）剂量、监测单位（MU）和治疗交付时间的汇总平均差异（MDs）及其 95%置信区间（CIs）。我们还进行了亚组分析，以评估不同的治疗计划系统（TPS）（Eclipse、Monaco 和 Pinnacle）的使用是否影响了汇总平均差异。
共有 17 项研究（383 例患者）符合纳入标准。汇总结果表明，双弧 VMAT 降低了 PTV 的 D2%（MD=0.71Gy，95%CI=0.14-1.27，P=0.01）、左耳蜗平均剂量（MD=2.6Gy，95%CI=0.03-5.16，P=0.05）、右耳蜗平均剂量（MD=3.4Gy，95%CI=0.7-6.1，P=0.01）、MU（MD=554.9，95%CI=245.8-863.9，P=0.0004）、治疗交付时间（MD=6.7min，95%CI=4.5-8.9，P<0.0001）和积分剂量（MD=0.97Gy，95%CI=0.28-1.67，P=0.006）。IMRT 计划在其他指标上没有明显更好的结果。亚组分析表明，只有 Eclipse 的积分剂量显著降低（MD=0.88Gy，95%CI=0.14-1.63，P=0.02）。只有 Eclipse（MD=1035.2，95%CI=624.6-1445.9，P<0.0001）和 Pinnacle（MD=293，95%CI=15.6-570.5，P=0.04）的总 MU 显著降低。同样，只有 Eclipse（MD=6.1min，95%CI=5.7-6.5，P<0.0001）和 Pinnacle（MD=4.9min，95%CI=2.6-7.2，P<0.0001）的交付时间也显著降低。然而，亚组分析表明，对于 Pinnacle（MD=0.48Gy，95%CI=0.31-0.66，P<0.0001）和 Monaco（MD=0.12Gy，95%CI=0.07-0.17，P<0.0001），IMRT 计划的靶区覆盖率更优。
与 IMRT 计划相比，双弧 VMAT 计划改善了 OAR 剂量、MU 和治疗时间。使用的不同 TPS 可能会改变剂量学结果。
