Rough Leila, Burbery Julie, Hargrave Catriona, Brown Elizabeth
Radiation Oncology Princess Alexandra Hospital Ipswich Road Brisbane, Brisbane, Queensland, Australia.
School of Clinical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Queensland, Australia.
J Med Radiat Sci. 2025 Jun;72(2):217-224. doi: 10.1002/jmrs.861. Epub 2025 Jan 30.
Image guided-radiation therapy (IGRT) protocols are adopted to ensure the accurate dose delivery of patient treatments. This is especially important in hypofractionated treatments, such as stereotactic body radiation therapy (SBRT), as high doses of radiation are delivered, and incorrect treatment can have a significant impact on tumour control and toxicity. This study aimed to establish mean treatment times from the localisation image to the post-treatment image in SBRT liver, lung and spine patients that utilised Elekta Intrafraction Imaging (IFI). The magnitude of intrafraction motion exhibited as time elapses during the treatment fraction was also determined.
IGRT data for 20 SBRT patients was retrospectively collected, including imaging times and shifts made from each pre-, during and post-treatment cone-beam computed tomography (CBCT) scan. Total treatment fraction time, time between each image acquired and the 3D vector of the shifts were calculated. Descriptive statistical analysis was performed.
The IGRT data associated with 332 CBCT images was evaluated. The average treatment time was longest in the liver (19.3 min), followed by lung (14.9 min) and spine (14.2 min). Liver patients had a mean shift 3D vector (0.1 cm), with 7.8% of shifts > 0.3 cm. Lung patients had a mean vector of 0.1 cm with 3.8% > 0.3 cm, and spine patients had a mean vector of 0 cm with 0% > 0.2 cm. Vectors > 0.3 cm occurred at multiple imaging timepoints (range: 4.9-24.4 min) for liver and lung patients.
Intrafraction imaging is required in liver and lung SBRT treatments to identify instances where clinical tolerances are exceeded.
采用图像引导放射治疗（IGRT）方案以确保患者治疗中剂量的准确输送。这在大分割治疗中尤为重要，如立体定向体部放射治疗（SBRT），因为要输送高剂量辐射，而不正确的治疗会对肿瘤控制和毒性产生重大影响。本研究旨在确定使用医科达内置分次成像（IFI）的SBRT肝脏、肺部和脊柱患者从定位图像到治疗后图像的平均治疗时间。还确定了在治疗分次过程中随着时间推移出现的分次内运动幅度。
回顾性收集20例SBRT患者的IGRT数据，包括成像时间以及每次治疗前、治疗期间和治疗后锥形束计算机断层扫描（CBCT）扫描的移位情况。计算总治疗分次时间、每次采集图像之间的时间以及移位的三维向量。进行描述性统计分析。
评估了与332幅CBCT图像相关的IGRT数据。平均治疗时间在肝脏患者中最长（19.3分钟），其次是肺部（14.9分钟）和脊柱（14.2分钟）。肝脏患者的平均移位三维向量为（0.1厘米），7.8%的移位>0.3厘米。肺部患者的平均向量为0.1厘米，3.8%>0.3厘米，脊柱患者的平均向量为0厘米，0%>0.2厘米。对于肝脏和肺部患者，在多个成像时间点（范围：4.9 - 24.4分钟）出现了>0.3厘米的向量。
在肝脏和肺部SBRT治疗中需要进行分次内成像，以识别超出临床耐受的情况。
