New Energy Sources for Local Ablation Therapy. Jeong Kyong Lee, MD Ewha Womans University

Transcription

1 New Energy Sources for Local Ablation Therapy Jeong Kyong Lee, MD Ewha Womans University

2 New Energy Sources for Local Ablation Therapy Microwave Ablation Irreversible Electroporation Cryoablation

3 Microwave Ablation

4 What is Microwave? 915-MHz or 2.45-GHz Dielectric hysteresis JVIR 2010; 21:S192-S203

5 Why Microwave?

6 Faster and Hotter! RFA, single, 3cm-tip, 12 min MWA, 2.45-GHz, single, 5 min Faster heating over a larger volume of tissue Produce extremely high temperature(>150 ) without charred tissue surrounding an electrode Easy penetration of low electrical conductivity (i.e. lung, bone, dehydrated or charred tissue)

7 Larger ablation zone CRC with liver mets, percutaneous 2.45GHz with 75-W (max), Two 17G antennas with 15cm-length Index tumor: 4cm #3(10/5/5min): 6.4x4.6cm 2

8 Less Heat-sink effect Pre-RFA Post-RFA Pre-MWA Post-MWA

9 Multiple antennas without switching Operation of multiple MW antennas simultaneously without switching Radiographics 2005;25: S69-S83 Radiology 2007;

10 No ground pads

11 Any Disadvantages of Microwave?

12 Shaft Heating JVIR 2010; 21:S192-S203 Higher power : Larger ablation zone : Larger diameter of antennas Shaft JVIR 2010; heating 21:S192-S203 by excessive power : unintended injury of surface organs, skin burn Cooling jacket reduces cable heating and increases power

13 Cumbersome Antenna RFA MWA Coaxial cable: Larger in diameter to carry larger power

14 Longer and Thinner! JVIR 2010; 21:S192-S203 Long and relatively thin ablation zone Some unpredictability as to the size and shape of ablation zones

15 Clinical Outcomes 1. Ablation zone size MWA > RFA (109 cm 3 vs 49 cm 3 ) 2. Complete ablation rate: 91%-95.5% 3. Local tumor progression rate: 5.1%-30% 4. Overall survival rates of 1 yr and 3 yrs: 81.6%-92.7%, 14%-80.4% 5. Major complication rate: 0%-8.2%

16 Clinical Outcomes MWA vs RFA in HCC 131 HCC with MWA vs 98 HCC with RFA Local tumor progression rate: 10.9% vs 5.2%, p = Disease-free survival rate at 3 yrs: 32.1% vs 39.5% OS at 3 yrs: 77.6% vs 82.7%, p = MWA vs RFA in CRLM A matched-cohort analysis in 254 tumors Local tumor progression rate at 2 yrs: 7% vs 18%, p = 0.01 Eur J Raiol 2013; 82: Ann Surg Oncol 2014 Jun, Epub

17 Clinical Application - Partial replacement of RFA in liver: Perivascular tumor Larger tumor (> cm) Metastasis - Promising in lung and bone tumor

18 Cryoablation

19 Principles of Cryoablation Argon gas 35 to min Helium gas min Freeze-thaw cycle: double or triple Erinjery JP, et al, J Vasc Interv Radiol Aug;21(8 Suppl):S187-91

20 Application of Cryoablation Liu X, et al. Conf Proc IEEE Eng Med Biol Soc Aug;2012:

21 Advantages Ability to monitor the ablation zone in real time: good visualization of iceball Multiple cryoprobes simultaneously: larger tumor Less collateral damage to ducts: central tumor No increase of intratumoral pressure: subcapsular tumor Less painful Rilling WS, et al. Semin Intervent Radiol March;23(1):33-38

22 Disadvantages Bleeding risk Cryoshock: DIC-like reaction, frequent in large-volume liver cryoablation Longer time Expensive

23 Clinical Outcomes RFA > Cryoablation in HCC local tumor progression, complication RCT of RFA vs Cryoablation in HCC 4 cm RFA = or < Cryoablation 3 yr LTP 11% vs 7% (p = 0.043) 18.2% vs 7.7% for HCC >3 cm 5 yr TFS 34% vs 35% (p = 0.628) Major Cx 3.3% vs 3.9% Wang C, et al. Hepatology 2015, In press

24 Clinical Application Possible option for ablation of hepatic tumor - tumors adjacent to vulnerable structures - tumors in subcapsular location Although the feasibility of small-volume cryoablation in HCC, it is difficult the justify the additional risk of cryoablation when heat-base alternatives are available.

25 Irreversible Electroporation

26 Principles of IRE Reversible pore: <1000 volt Irreversible pore: volt nanopore permeability cell death

27 Application of IRE Tx. of Index tumor 3-4cm volt -pulse length: μsec -pulse repetition: spacing: cm

28 Advantages 1. Non-thermal ablation 2. No collateral damage: vessels, nerves, GI tract, bile duct, collagenous tissue US 3. No heat-sink effect: perivascular tumor 4. Larger ablation within seconds or minutes Pre-IRE Post-IRE, 4 th day Post-IRE, 4 mon

29 Disadvantages General anesthesia Laparotomy Muscle contraction Risk with cardiac arrhythmia or irregular heart beat

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31 Clinical Outcomes A systemic review of safety and efficacy J Vasc Interv Radiol 2014; 25:

32 Clinical Application Optional for tumor in perivascular, portal hepatis.. Unresectable pancreatic cancer Unresectable bile duct cancer

33 In conclusion Central or perivascular IRE Cryo Central or subcapsular Inoperative pancreatic or bile duct cancer IRE MWA >2 cm Mets perivascular RFA 2 cm

34 Thank You!