Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kinki University School of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama 589-8511, Japan.
Eur J Radiol. 2012 Mar;81(3):e277-80. doi: 10.1016/j.ejrad.2011.02.026. Epub 2011 Mar 10.
Virtual CT sonography using magnetic navigation provides cross sectional images of CT volume data corresponding to the angle of the transducer in the magnetic field in real-time. The purpose of this study was to clarify the value of this virtual CT sonography for treatment response of radiofrequency ablation for hepatocellular carcinoma.
Sixty-one patients with 88 HCCs measuring 0.5-1.3 cm (mean±SD, 1.0±0.3 cm) were treated by radiofrequency ablation. For early treatment response, dynamic CT was performed 1-5 days (median, 2 days). We compared early treatment response between axial CT images and multi-angle CT images using virtual CT sonography.
Residual tumor stains on axial CT images and multi-angle CT images were detected in 11.4% (10/88) and 13.6% (12/88) after the first session of RFA, respectively (P=0.65). Two patients were diagnosed as showing hyperemia enhancement after the initial radiofrequency ablation on axial CT images and showed local tumor progression shortly because of unnoticed residual tumors. Only virtual CT sonography with magnetic navigation retrospectively showed the residual tumor as circular enhancement. In safety margin analysis, 10 patients were excluded because of residual tumors. The safety margin more than 5 mm by virtual CT sonographic images and transverse CT images were determined in 71.8% (56/78) and 82.1% (64/78), respectively (P=0.13). The safety margin should be overestimated on axial CT images in 8 nodules.
Virtual CT sonography with magnetic navigation was useful in evaluating the treatment response of radiofrequency ablation therapy for hepatocellular carcinoma.
利用磁场导航的虚拟 CT 超声可实时提供与磁场中换能器角度相对应的 CT 容积数据的横断图像。本研究旨在阐明这种虚拟 CT 超声在评估肝癌射频消融治疗反应中的价值。
对 61 例 88 个直径 0.5-1.3cm（平均值±标准差，1.0±0.3cm）的 HCC 患者进行了射频消融治疗。对于早期治疗反应，在消融后 1-5 天（中位数 2 天）进行动态 CT 检查。我们比较了使用虚拟 CT 超声的轴向 CT 图像和多角度 CT 图像在早期治疗反应方面的差异。
在第一次射频消融后，轴向 CT 图像和多角度 CT 图像上均检测到 11.4%（10/88）和 13.6%（12/88）的肿瘤残留染色（P=0.65）。2 例患者在轴向 CT 图像上表现为初始射频消融后的充血增强，由于未注意到残留肿瘤，很快出现局部肿瘤进展。只有使用磁场导航的虚拟 CT 超声才能回顾性显示残留肿瘤呈圆形增强。在安全边缘分析中，由于存在肿瘤残留，有 10 例患者被排除在外。通过虚拟 CT 超声图像和横轴 CT 图像确定的安全边缘大于 5mm 的分别有 71.8%（56/78）和 82.1%（64/78）（P=0.13）。在 8 个结节中，轴向 CT 图像上的安全边缘被高估。
利用磁场导航的虚拟 CT 超声在评估肝癌射频消融治疗反应方面是有用的。
