Berber E, Herceg N L, Casto K J, Siperstein A E
Department of General Surgery, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
Surg Endosc. 2004 Mar;18(3):390-6. doi: 10.1007/s00464-003-8911-5. Epub 2004 Jan 23.
Radiofrequency ablation (RFA) is gaining increased acceptance for the local control of liver tumors. Essential for achieving local tumor control are reproducible volumes of ablation that encompass the tumor and a margin of normal liver parenchyma. The technical algorithm for performing ablations was arrived at in an animal model using normal liver. Limited amounts of data exist as to whether this translates to the human tumor model.
We analyzed 531 ablated lesions in 154 patients undergoing laparoscopic RFA using RITA Medical Systems Starburst XL catheter deployed to a final diameter of 2-5 cm. The first 54 patients (algorithm 1) were treated with a larger initial deployment to 3 cm and incremental advancement of the catheter to the final diameter with a 20-min ablation time for a 5-cm lesion. The subsequent 100 patients (algorithm 2) were treated with a smaller initial deployment of 2 cm, incremental advancement to the final diameter, and 14-min total ablation time for a 5-cm lesion. Lesion size was measured on 1 week postablation CT scans. Analysis was performed using the two-tailed t-test.
Ablation zones tended to be larger with the second method. On 1 week postablation CT scans, mean +/- SEM lesion sizes created using the first and second algorithms were 3.7 +/- 0.1 cm vs 4.0 +/- 0.1 cm at 3 cm deployment ( p < 0.05); 4.3 +/- 0.1 cm vs 4.8 +/- 0.1 cm at 4 cm deployment ( p < 0.05), and 5.5 +/- 0.1 cm vs 5.6 +/- 0.2 cm at 5 cm deployment ( p > 0.05), respectively. The mean +/- SEM total ablation times for the first and second algorithms were 7.9 +/- 0.3 min vs 7.0 +/- 0.2 min at 3 cm deployment ( p < 0.05); 13.3 +/- 0.3 min vs 11.1 +/- 0.02 min at 4 cm deployment ( p < 0.05); and 27.8 +/- 1.2 min vs 21.4 +/- 1.2 min at 5 cm deployment ( p < 0.05), respectively. The small SEM values indicate little variation in lesion size.
These results show that both algorithms create dependable and reproducible zones of ablation, essential for reliable tumor destruction. Algorithm 2 demonstrates that creating an initial small core of ablation with rapid coagulation of the center of the lesion allows for equivalent, if not larger, final volumes to be performed in less time.
射频消融术（RFA）在肝脏肿瘤的局部控制方面越来越被广泛接受。实现局部肿瘤控制的关键是要有可重复的消融体积，该体积要包含肿瘤以及一定边缘的正常肝实质。在使用正常肝脏的动物模型中得出了进行消融的技术算法。关于这是否能转化到人类肿瘤模型的数据有限。
我们分析了154例接受腹腔镜RFA治疗患者的531个消融病灶，使用的是RITA Medical Systems Starburst XL导管，最终直径为2 - 5厘米。前54例患者（算法1）最初以较大直径3厘米展开，然后将导管逐步推进至最终直径，对于5厘米的病灶采用20分钟的消融时间。随后的100例患者（算法2）最初以较小直径2厘米展开，逐步推进至最终直径，对于5厘米的病灶总消融时间为14分钟。在消融后1周的CT扫描上测量病灶大小。使用双侧t检验进行分析。
第二种方法的消融区往往更大。在消融后1周的CT扫描上，使用第一种和第二种算法在3厘米展开时的平均±标准误病灶大小分别为3.7±0.1厘米和4.0±0.1厘米（p < 0.05）；在4厘米展开时分别为4.3±0.1厘米和4.8±0.1厘米（p < 0.05）；在5厘米展开时分别为5.5±0.1厘米和5.6±0.2厘米（p > 0.05）。第一种和第二种算法在3厘米展开时的平均±标准误总消融时间分别为7.9±0.3分钟和7.0±0.2分钟（p < 0.05）；在4厘米展开时分别为13.3±0.3分钟和11.1±0.02分钟（p < 0.05）；在5厘米展开时分别为27.8±1.2分钟和21.4±1.2分钟（p < 0.05）。较小的标准误数值表明病灶大小变化很小。
这些结果表明两种算法都能创建可靠且可重复的消融区，这对于可靠地破坏肿瘤至关重要。算法2表明，通过快速凝固病灶中心形成初始小的消融核心，能够在更短时间内实现相当甚至更大的最终消融体积。
