a Department of Radiation Oncology (MAASTRO) , GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre , Maastricht , The Netherlands.
b Proton Therapy Centre South-East Netherlands (ZON-PTC) , Maastricht , The Netherlands.
Acta Oncol. 2019 Jan;58(1):57-65. doi: 10.1080/0284186X.2018.1529424. Epub 2018 Nov 26.
Patients with low-grade glioma (LGG) have a prolonged survival expectancy due to better discriminative tumor classification and multimodal treatment. Consequently, long-term treatment toxicity gains importance. Contemporary radiotherapy techniques such as intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), tomotherapy (TOMO) and intensity-modulated proton therapy (IMPT) enable high-dose irradiation of the target but they differ regarding delivered dose to organs at risk (OARs). The aim of this comparative in silico study was to determine these dosimetric differences in delivered doses.
Imaging datasets of 25 LGG patients having undergone postoperative radiotherapy were included. For each of these patients, in silico treatment plans to a total dose of 50.4 Gy to the target volume were generated for the four treatment modalities investigated (i.e., IMRT, VMAT, TOMO, IMPT). Resulting treatment plans were analyzed regarding dose to target and surrounding OARs comparing IMRT, TOMO and IMPT to VMAT.
In total, 100 treatment plans (four per patient) were analyzed. Compared to VMAT, the IMPT mean dose (D) for nine out of 10 (90%) OARs was statistically significantly (p < .02) reduced, for TOMO this was true in 3/10 (30%) patients and for 1/10 (10%) patients for IMRT. IMPT was the prime modality reducing dose to the OARs followed by TOMO.
The low dose volume to the majority of OARs was significantly reduced when using IMPT compared to VMAT. Whether this will lead to a significant reduction in neurocognitive decline and improved quality of life is to be determined in carefully designed future clinical trials.
由于肿瘤分类更加准确和采用了多模态治疗，低级别胶质瘤（LGG）患者的预期生存时间延长。因此，长期治疗毒性变得尤为重要。调强放疗（IMRT）、容积调强弧形治疗（VMAT）、托姆治疗（TOMO）和调强质子治疗（IMPT）等现代放疗技术可以实现靶区的高剂量照射，但它们在靶区和危及器官（OARs）的剂量分布上存在差异。本研究旨在通过计算模拟来比较这几种放疗技术在靶区和危及器官剂量分布上的差异。
本研究纳入了 25 例接受术后放疗的 LGG 患者的影像学数据。对每位患者，我们为四种放疗技术（IMRT、VMAT、TOMO 和 IMPT）生成了 50.4Gy 总剂量的虚拟治疗计划。对生成的治疗计划进行分析，比较了靶区剂量和周围 OARs 的剂量，同时比较了 IMRT、TOMO 和 IMPT 与 VMAT 的剂量分布。
共分析了 100 份治疗计划（每位患者 4 份）。与 VMAT 相比，90%（9/10）的 OARs 的 IMPT 平均剂量（D）显著降低（p<0.02），30%（3/10）的 TOMO 和 10%（1/10）的 IMRT 患者也存在这种情况。降低 OARs 剂量方面，IMPT 优于 TOMO。
与 VMAT 相比，IMPT 可显著降低大多数 OAR 的低剂量体积。是否会导致神经认知功能下降的显著减少和生活质量的提高，需要在精心设计的未来临床试验中进一步验证。
Zotero 插件