Stippel Dirk L, Bangard Christopher, Prenzel Klaus, Yavuzyasar Selim, Fischer Jürgen H, Hölscher Arnulf H
Department of Visceral and Vascular Surgery, University of Cologne, Joseph-Stelzmann-Strasse 9, 50931, Cologne, Germany.
Langenbecks Arch Surg. 2009 Jul;394(4):671-9. doi: 10.1007/s00423-008-0306-6. Epub 2008 Feb 21.
The use of radiofrequency ablation (RFA) for treatment of liver malignancies is limited by the high rate of local recurrences. The aim of this experimental study was to evaluate parameters describing the reproducible target volume of a RFA procedure in order to facilitate better applicator placement.
RFA was performed in perfused and nonperfused pig livers. The following parameters were measured: axial and transverse diameter, front margin, coagulation center, diameter of sphere ablated (D(S)), distance to center (DC), and volume. Graphic overlays were utilized to visualize variability. Parameters were evaluated for Rita XL (2 algorithms), LeVeen, and Rita Xli applicators.
The best prediction of a reproducibly ablated target volume can be made by the diameter of the sphere ablated and the distance of the applicator tip to center of the sphere (DC). The spheres were significantly different in diameter (D(S)) depending on the applicator Rita XL 29 +/- 6 mm, Rita XL(wet) 35 +/- 5 mm, LeVeen 35 +/- 8 mm, Rita Xli 44 +/- 5 mm (perfused livers, p < 0.001). Graphic overlay demonstrated differences in variability that can influence the reliability of the system.
D(S) and DC as specific values for each applicator and algorithm facilitate a placement of the applicator relative to the target volume that maximizes the chance of complete ablation.
射频消融（RFA）治疗肝脏恶性肿瘤受到局部复发率高的限制。本实验研究的目的是评估描述RFA手术可重复目标体积的参数，以促进更好地放置消融器。
在灌注和未灌注的猪肝中进行RFA。测量以下参数：轴向和横向直径、前缘、凝固中心、消融球体直径（D(S)）、到中心的距离（DC）和体积。利用图形叠加来可视化变异性。对Rita XL（2种算法）、LeVeen和Rita Xli消融器的参数进行了评估。
通过消融球体直径和消融器尖端到球体中心的距离（DC）可以对可重复消融的目标体积做出最佳预测。根据消融器的不同，球体直径（D(S)）有显著差异，Rita XL为29±6mm，Rita XL（湿）为35±5mm，LeVeen为35±8mm，Rita Xli为44±5mm（灌注肝脏，p<0.001）。图形叠加显示了变异性的差异，这可能会影响系统的可靠性。
D(S)和DC作为每种消融器和算法的特定值，有助于将消融器相对于目标体积进行放置，从而最大限度地提高完全消融的机会。
