Hiraoka Shinya, Hirashima Hideaki, Nakamura Mitsuhiro, Tanaka Fumiya, Adachi Hiroki, Ono Yuka, Ono Tomohiro, Nakashima Ryota, Nakajima Aya, Mizowaki Takashi
Department of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Japan.
Department of Advanced Medical Physics, Graduate School of Medicine, Kyoto University, Japan.
Radiother Oncol. 2025 Jun;207:110879. doi: 10.1016/j.radonc.2025.110879. Epub 2025 Apr 4.
OXRAY is a new O-ring-shaped radiotherapy system delivering biaxially rotational dynamic-radiation therapy (BROAD-RT), a technique that enables non-coplanar volumetric-modulated arc therapy (VMAT) for large target volumes without requiring couch movement. The purpose of this study was to evaluate the benefits of BROAD-RT and to perform an integration test to confirm the plan deliverability and its accuracy from the treatment planning system to OXRAY for patients with nasopharyngeal carcinoma.
We compared treatment plans for BROAD-RT and coplanar VMAT (COVMAT) created in RayStation for 15 patients with nasopharyngeal cancer using the Wilcoxon signed-rank test. P values less than 0.05 were considered statistically significant. Additionally, we confirmed the plan delivery accuracy of BROAD-RT from the treatment planning system to OXRAY; gamma passing rates (GPRs) and delivery time were evaluated. The criteria for pass and fail were ≥95 % at γ3%2 mm.
BROAD-RT significantly improved the homogeneity and conformity index of planning target volume and reduced dose volume indices compared with COVMAT in D for the brainstem, D for the left optic nerve, D for the brachial plexus, D for each submandibular gland, D for the oral cavity, and D for each parotid gland. All plans for BROAD-RT passed the integration test; the mean GPR (3 %/2 mm) was above 95 % and the median delivery time was 209 s.
BROAD-RT delivered by OXRAY passed the integration test, and it demonstrated the potential benefit of improving the dose distribution compared with COVMAT for patients with nasopharyngeal carcinoma.
OXRAY是一种新型O形环放射治疗系统，可进行双轴旋转动态放射治疗（BROAD-RT），该技术能够在无需治疗床移动的情况下，对大靶区进行非共面容积调强弧形治疗（VMAT）。本研究旨在评估BROAD-RT的优势，并进行整合测试，以确认鼻咽癌患者从治疗计划系统到OXRAY的计划可交付性及其准确性。
我们使用Wilcoxon符号秩检验比较了在RayStation中为15例鼻咽癌患者创建的BROAD-RT和共面VMAT（COVMAT）的治疗计划。P值小于0.05被认为具有统计学意义。此外，我们确认了从治疗计划系统到OXRAY的BROAD-RT计划交付准确性；评估了伽马通过率（GPR）和交付时间。通过和失败的标准为γ3%2mm时≥95%。
与COVMAT相比，BROAD-RT显著提高了计划靶区的均匀性和适形指数，并降低了脑干D、左侧视神经D、臂丛神经D、每个下颌下腺D、口腔D和每个腮腺D的剂量体积指数。所有BROAD-RT计划均通过了整合测试；平均GPR（3%/2mm）高于95%，中位交付时间为209秒。
OXRAY提供的BROAD-RT通过了整合测试，并且与COVMAT相比，它显示出改善鼻咽癌患者剂量分布的潜在益处。
