Gupta Anil, Kumar Rishabh, Yadav Hanuman Prasad, Sharma Manik, Kamal Rose, Thaper Deepak, Banik Prabir, Gupta Shipra, Saroha Kartik, Singh Sandeep, Kumar Sarin Shiv
Radiation Oncology, Institute of Liver and Biliary Sciences, Delhi, India.
Nuclear Medicine, Institute of Liver and Biliary Sciences, Delhi, India.
Rep Pract Oncol Radiother. 2020 Mar-Apr;25(2):293-298. doi: 10.1016/j.rpor.2019.12.006. Epub 2019 Dec 13.
Delivering Stereotactic Body Radiotherapy (SBRT) for Hepatocellular Carcinoma (HCC) is challenging mainly for two reasons: first, motion of the liver occurs in six degrees of freedom and, second, delineation of the tumor is difficult owing to a similar density of HCC to that of the adjoining healthy liver tissue in a non-contrast CT scan. To overcome both these challenges simultaneously, we performed a feasibility study to synchronize intravenous contrast to obtain an arterial and a delayed phase 4D CT.
We included seven HCC patients of planned for SBRT. 4D CT simulation was performed with synchronized intravenous contrast based on the formula T - (L/Detector Coverage × Cine Duration in Seconds). This was followed by a delayed 4D CT scan.
We found that, with our protocol, it is feasible to obtain a 4DCT with an arterial and a delayed phase making it comparable to a diagnostic multi-phase CT. The peak HU of the 4D scan and diagnostic CT were similar (mean peak HU 134.2 vs 143.1, p value = 0.58 N.S). Whereas in comparison with a non-contrast CT a significant rise in the peak HU was seen (mean peak 134.2 vs 61.4 p value = .00003).
A synchronized contrast 4D CT simulation for HCC is safe and feasible. It results in good contrast enhancement comparable to a diagnostic 3D contrast CT scan.
对肝细胞癌（HCC）进行立体定向体部放疗（SBRT）具有挑战性，主要有两个原因：第一，肝脏的运动在六个自由度上发生；第二，在非增强CT扫描中，由于HCC与相邻健康肝组织的密度相似，肿瘤的勾画很困难。为了同时克服这两个挑战，我们进行了一项可行性研究，以同步静脉注射造影剂来获取动脉期和延迟期的4D CT。
我们纳入了7例计划接受SBRT的HCC患者。基于公式T - （L/探测器覆盖范围×电影时长（秒）），使用同步静脉注射造影剂进行4D CT模拟。随后进行延迟4D CT扫描。
我们发现，按照我们的方案，获得动脉期和延迟期的4D CT是可行的，使其与诊断性多期CT相当。4D扫描和诊断性CT的峰值HU相似（平均峰值HU 134.2对143.1，p值 = 0.58，无统计学意义）。而与非增强CT相比，峰值HU有显著升高（平均峰值134.2对61.4，p值 = 0.00003）。
对HCC进行同步造影剂4D CT模拟是安全可行的。它能产生与诊断性3D造影CT扫描相当的良好对比增强效果。
