COMBO WCIO 5-25-2017pdf
Combination Therapies: Quantifying the Effects of Transarterial Embolization on Microwave Ablation Zones Erica M. Knavel, M.D., Christopher L. Brace, Ph.D., Paul F. Laeseke M.D., Ph.D. Background
Figure 1. Procedural Images
There is increasing interest in combining transarterial embolization (TAE) and thermal ablation for treating large, poorly visualized, or infiltrative hepatocellular carcinomas. Improved oncologic outcomes are demonstrated when compared with either therapy alone with several retrospective studies demonstrating improved overall survival (OS), improved recurrence-free survival and decreased rate of disease progression with combination therapy (TACE combined with MW or RF ablation) compared to ablation alone for the treatment of HCC.1-6
3
No data exists regarding the effect of transarterial embolization on the size, shape and reproducibility of subsequent microwave ablations.
4
2 1
The purpose of this study is to quantify the effect of TAE on microwave ablations in an in vivo porcine liver model.
Materials & Methods Femoral arterial approach arteriograms and cone beam CT scans were performed to delineate hepatic arterial anatomy and identify individual branches supplying each of the four liver lobes in 6 female domestic swine. Two of the four liver lobes were embolized to near stasis (5 beat stasis) with 100-300μm Embosphere® Microspheres (Merit Medical Systems, Inc., South Jordan, UT). Microwave ablations (65 W, 5 min) were created in both embolized (TAE-MW, n=15) and non-embolized (MW, n= 12) portions of the liver using a 2.45 GHz system and single antenna (Certus 140 and PR-15, NeuWave Medical, Inc., Madison WI). A mixed effects model was used to compare the TAE-MW and MW groups.
Figure 2 :Ablation Temperatures
Table 1: Comparison of ablation zone metrics
Measurement
TAE + MW Ablation
MW Ablation
A. Hepatic arteriogram demonstrating porcine anatomy: 1. Right Lateral Branch 2. Right Medial Branch 3. Left Medial Branch 4. Left Lateral Branch
B. Hepatic arteriogram following bland particle embolization of the Left Medial and Left Lateral Branches demonstrating truncation of the embolized branches
Performing TAE prior to microwave ablation increases ablation zone diameter and area by approximately 27% and 66%, respectively.
A
*
P-‐Value
11.8 ± 2.5
7.1 ± 1.9
< 0.0001
Length (cm)
4.8 ± 0.5
3.7 ± 0.6
< 0.0001
Diameter (cm)
3.1 ± 0.6
2.4 ± 0.3
0.0010
Central Zone Diameter (cm)
1.7 ± 0.2
1.6 ± 0.2
0.2191
Peripheral Zone Width (cm)
1.3 ± 0.4
0.8 ± 0.2
0.0007
Circularity
0.84 ± 0.06
0.83 ± 0.06
0.8942
D. En bloc liver specimen demonstrating post embolization changes with the embolized left lobes and the non embolized right lobes
Discussion
Figure 3. Combination therapy vs. Ablation only
B
*
(n = 7, Mean ± SD) (n = 5, Mean ± SD) Area (cm2)
C. Cone Beam CT confirming positioning of left medial ablation antenna (arrowhead) into the embolized lobe (delineated by retained contrast and white border) and placement of the right medial ablation antenna (arrow) in the non embolized lobe
This size increase is due to an increase in the size of the peripheral portion of the ablation zone, which is most susceptible to perfusion mediated cooling and heat sinks. Further studies are warranted to characterize the effect of particle size, timing of the embolization, and different microwave power/time combinations on the resultant ablation zones.
2 cm 2 cm
Mean temperatures recorded 1 cm from MW antenna during two control MW ablations and two MW ablations performed after TAE. Note the faster heating and higher maximum temperatures associated with MW ablation after TAE.
A. Combination therapy specimen and B. MW ablation specimen demonstrating increased total size and increased size of the peripheral non charred zone (Asterisk) of sample A compared to sample B. The charred central portion (Triangle) was not significantly different between the two groups.
References 1. Ni JY, Liu SS, Xu LF, Sun HL, Chen YT. Meta-analysis of radiofrequency ablation in combination with transarterial chemoembolization for hepatocellular carcinoma. World J Gastroenterol. 2013;;19(24):3872-82. 2. Peng ZW, Zhang YJ, Chen MS, Xu L, Liang HH, Lin XJ, Guo RP, Zhang YQ, Lau WY. Radiofrequency ablation with or without transcatheter arterial chemoembolization in the treatment of hepatocellular carcinoma: a prospective randomized trial. J Clin Oncol. 2013;;31(4):426-32. 3. Yang WZ, Jiang N, Huang N, Huang JY, Zheng QB, Shen Q. Combined therapy with transcatheter arterial chemoembolization and percutaneous microwave coagulation for small hepatocellular carcinoma. World J Gastroenterol. 2009;;15(6):748-52. 4. Seki T, Tamai T, Nakagawa T, Imamura M, Nishimura A, Yamashiki N, Ikeda K, Inoue K. Combination therapy with transcatheter arterial chemoembolization and percutaneous microwave coagulation therapy for hepatocellular carcinoma. Cancer. 2000;;89(6):1245-51. 5. Li W, Man W, Guo H, Yang P. Clinical study of transcatheter arterial chemoembolization combined with microwave ablation in the treatment of advanced hepatocellular carcinoma. J Cancer Res Ther. 2016;;12(Supplement):C217-C20. 6. Ginsburg M, Zivin SP, Wroblewski K, Doshi T, Vasnani RJ, Van Ha TG. Comparison of Combination Therapies in the Management of Hepatocellular Carcinoma: Transarterial Chemoembolization with Radiofrequency Ablation versus Microwave Ablation. J Vasc Interv Radiol. 2015;;26(3):330-41.
Figure 1. Procedural Images
There is increasing interest in combining transarterial embolization (TAE) and thermal ablation for treating large, poorly visualized, or infiltrative hepatocellular carcinomas. Improved oncologic outcomes are demonstrated when compared with either therapy alone with several retrospective studies demonstrating improved overall survival (OS), improved recurrence-free survival and decreased rate of disease progression with combination therapy (TACE combined with MW or RF ablation) compared to ablation alone for the treatment of HCC.1-6
3
No data exists regarding the effect of transarterial embolization on the size, shape and reproducibility of subsequent microwave ablations.
4
2 1
The purpose of this study is to quantify the effect of TAE on microwave ablations in an in vivo porcine liver model.
Materials & Methods Femoral arterial approach arteriograms and cone beam CT scans were performed to delineate hepatic arterial anatomy and identify individual branches supplying each of the four liver lobes in 6 female domestic swine. Two of the four liver lobes were embolized to near stasis (5 beat stasis) with 100-300μm Embosphere® Microspheres (Merit Medical Systems, Inc., South Jordan, UT). Microwave ablations (65 W, 5 min) were created in both embolized (TAE-MW, n=15) and non-embolized (MW, n= 12) portions of the liver using a 2.45 GHz system and single antenna (Certus 140 and PR-15, NeuWave Medical, Inc., Madison WI). A mixed effects model was used to compare the TAE-MW and MW groups.
Figure 2 :Ablation Temperatures
Table 1: Comparison of ablation zone metrics
Measurement
TAE + MW Ablation
MW Ablation
A. Hepatic arteriogram demonstrating porcine anatomy: 1. Right Lateral Branch 2. Right Medial Branch 3. Left Medial Branch 4. Left Lateral Branch
B. Hepatic arteriogram following bland particle embolization of the Left Medial and Left Lateral Branches demonstrating truncation of the embolized branches
Performing TAE prior to microwave ablation increases ablation zone diameter and area by approximately 27% and 66%, respectively.
A
*
P-‐Value
11.8 ± 2.5
7.1 ± 1.9
< 0.0001
Length (cm)
4.8 ± 0.5
3.7 ± 0.6
< 0.0001
Diameter (cm)
3.1 ± 0.6
2.4 ± 0.3
0.0010
Central Zone Diameter (cm)
1.7 ± 0.2
1.6 ± 0.2
0.2191
Peripheral Zone Width (cm)
1.3 ± 0.4
0.8 ± 0.2
0.0007
Circularity
0.84 ± 0.06
0.83 ± 0.06
0.8942
D. En bloc liver specimen demonstrating post embolization changes with the embolized left lobes and the non embolized right lobes
Discussion
Figure 3. Combination therapy vs. Ablation only
B
*
(n = 7, Mean ± SD) (n = 5, Mean ± SD) Area (cm2)
C. Cone Beam CT confirming positioning of left medial ablation antenna (arrowhead) into the embolized lobe (delineated by retained contrast and white border) and placement of the right medial ablation antenna (arrow) in the non embolized lobe
This size increase is due to an increase in the size of the peripheral portion of the ablation zone, which is most susceptible to perfusion mediated cooling and heat sinks. Further studies are warranted to characterize the effect of particle size, timing of the embolization, and different microwave power/time combinations on the resultant ablation zones.
2 cm 2 cm
Mean temperatures recorded 1 cm from MW antenna during two control MW ablations and two MW ablations performed after TAE. Note the faster heating and higher maximum temperatures associated with MW ablation after TAE.
A. Combination therapy specimen and B. MW ablation specimen demonstrating increased total size and increased size of the peripheral non charred zone (Asterisk) of sample A compared to sample B. The charred central portion (Triangle) was not significantly different between the two groups.
References 1. Ni JY, Liu SS, Xu LF, Sun HL, Chen YT. Meta-analysis of radiofrequency ablation in combination with transarterial chemoembolization for hepatocellular carcinoma. World J Gastroenterol. 2013;;19(24):3872-82. 2. Peng ZW, Zhang YJ, Chen MS, Xu L, Liang HH, Lin XJ, Guo RP, Zhang YQ, Lau WY. Radiofrequency ablation with or without transcatheter arterial chemoembolization in the treatment of hepatocellular carcinoma: a prospective randomized trial. J Clin Oncol. 2013;;31(4):426-32. 3. Yang WZ, Jiang N, Huang N, Huang JY, Zheng QB, Shen Q. Combined therapy with transcatheter arterial chemoembolization and percutaneous microwave coagulation for small hepatocellular carcinoma. World J Gastroenterol. 2009;;15(6):748-52. 4. Seki T, Tamai T, Nakagawa T, Imamura M, Nishimura A, Yamashiki N, Ikeda K, Inoue K. Combination therapy with transcatheter arterial chemoembolization and percutaneous microwave coagulation therapy for hepatocellular carcinoma. Cancer. 2000;;89(6):1245-51. 5. Li W, Man W, Guo H, Yang P. Clinical study of transcatheter arterial chemoembolization combined with microwave ablation in the treatment of advanced hepatocellular carcinoma. J Cancer Res Ther. 2016;;12(Supplement):C217-C20. 6. Ginsburg M, Zivin SP, Wroblewski K, Doshi T, Vasnani RJ, Van Ha TG. Comparison of Combination Therapies in the Management of Hepatocellular Carcinoma: Transarterial Chemoembolization with Radiofrequency Ablation versus Microwave Ablation. J Vasc Interv Radiol. 2015;;26(3):330-41.
