Abstract

Purpose

To evaluate microwave ablation (MWA) algorithms, comparing pulsed and continuous mode in an in vivo lung tumor mimic model

Materials and methods

A total of 43 lung tumor-mimic models of 1, 2 or 3 cm were created in 11 pigs through an intra-pulmonary injection of contrast-enriched minced muscle. Tumors were ablated under fluoroscopic and 3D-CBCT-guidance using a single microwave antenna. Continuous (CM) and pulsed mode (PM) were used. According to tumor size, 3 different algorithms for both continuous and pulsed mode were used. The ablation zones were measured using post-procedural 3D-CBCT and on pathologic specimens.

Results

Two radiologists measured the ablation zones on CBCT and they significantly correlated with macroscopic and microscopic pathological findings: r = 0.75 and 0.74 respectively (p < 0.0001) (inter-observer correlation r = 0.9). For 1, 2 and 3 cm tumors mimics lesions (TMLs), mean maximal and transverse ablation diameters were 3.6 $\pm$ 0.3 × 2.2 $\pm$ 0.3 cm; 4.1 $\pm$ 0.5 × 2.6 $\pm$ 0.3 cm and 4.8 $\pm$ 0.3 × 3.2 $\pm$ 0.3 cm respectively using CM; And, 3.0 $\pm$ 0.2 × 2.1 $\pm$ 0.2 cm; 4.0 $\pm$ 0.4 × 2.7 $\pm$ 0.4 cm and 4.6 $\pm$ 0.4 × 3.2 $\pm$ 0.4 cm respectively for PM, without any significant difference except for 1 cm TMLs treated by PM ablation which were significantly smaller (p = 0.009) The sphericity index was 1.6, 1.6, 1.5 and 1.4, 1.5, 1.4 at 1, 2 and 3 cm for CM and PM respectively, p = 0.07, 0.14 and 0.13 for 1, 2 and 3 cm tumors mimics.

Conclusion

Microwave ablation for 1–3 cm lung tumors were successfully realized but with a moderate reproducibility rate, using either CM or PM. Immediate post ablation CBCT can accurately evaluate ablation zones.

中文翻译：

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肺微波消融-一种体内猪肿瘤模型实验，用于评估消融区域。

摘要

目的

若要评估微波消融（MWA）算法，在体内肺肿瘤模拟模型中比较脉冲模式和连续模式

材料和方法

通过肺内注射富含对比剂的切碎的肌肉，在11头猪中总共创建了43个1、2或3厘米的肺肿瘤模拟模型。使用单个微波天线在荧光镜和3D-CBCT指导下消融肿瘤。使用连续（CM）和脉冲模式（PM）。根据肿瘤大小，针对连续和脉冲模式使用了3种不同的算法。使用手术后3D-CBCT和病理标本测量消融区。

结果

两名放射科医生测量了CBCT上的消融区，它们与宏观和微观病理学发现显着相关：r 分别为0.75和0.74（p  <0.0001）（观察者间相关性r  = 0.9）。对于1、2和3厘米的肿瘤模拟病变（TML），平均最大和横向消融直径为3.6 $\pm$ 0.3×2.2 $\pm$ 0.3厘米; 4.1 $\pm$ 0.5×2.6 $\pm$ 0.3厘米和4.8 $\pm$ 0.3×3.2 $\pm$ 使用CM分别为0.3厘米；并且，3.0 $\pm$ 0.2×2.1 $\pm$ 0.2厘米 4.0 $\pm$ 0.4×2.7 $\pm$ 0.4厘米和4.6 $\pm$ 0.4×3.2 $\pm$ PM分别为0.4 cm，除经PM消融处理的1 cm TML显着较小（p  = 0.009）外，无其他显着性差异（p = 0.009）。1、2和3 cm处的球形指数分别为1.6、1.6、1.5和1.4、1.5、1.4对于CM和PM，分别 针对1、2和3 cm的肿瘤模拟物，p = 0.07、0.14和0.13。

结论

使用CM或PM，已成功实现了1-3 cm肺部肿瘤的微波消融，但再现率中等。消融后立即进行CBCT可以准确评估消融区域。