chemoembolization, cryotherapy and microwave thermotherapy fred t. lee jr., md university of...
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Chemoembolization, Cryotherapy and
Microwave ThermotherapyFred T. Lee Jr., MD
University of Wisconsin Dept. of Radiology
• Chemoembolization• Chemoembolization+RF• Cryotherapy• Microwave thermotherapy• Comparison of techniques
Chemoembolization
• Delivery of concentrated chemotherapy to liver via hepatic artery
• Used for hepatocellular carcinoma and metastases (lobar or segmental)
• Less systemic side effects than IV chemotherapy
Chemoembolization
Indications• Unresectable HCC or liver mets• Nonsurgical candidates• Single or multiple lesions• Palliation/selective prolongation of life
Chemoembolization:Contraindications
• Total bilirubin>3.5
• Portal Vein Thrombosis
• Active Infection
Chemoembolization:
• Prep: bowel, skin, Abx, steroids, hydration
• Selective, superselective catherization of tumor vessels bypass GDA, cystic artery
• Slowly inject “cocktail”
Wisconsin “cocktail”Cisplatin 100 mg
Mitomycin C 10 mg
Adriamycin 50 mg
Ethiodol 10 cc
Contrast 8 cc
Ivalon particles 300-500 µ
McDermott J, Wojtowycz M, Sproat I, Omary R,Salem R, Wagner HJ
Results (many different cocktails, protocols)
• Mets: response rates, but probably no survival advantage. Palliation.
• HCC: High local tumor response rates. Probably no survival advantage vs. symptomatic rx. Less effective than surgery in resectable patients.
Pelletier. J Hep 1998
Kanematsu. Cancer 1993
RF Ablation: Why We Fail
• Mets: local failures=30-50%• Miss lesion• Cover, but don’t kill entire tumor• Most failures occur in the rim:
vessels!
Cooled-tip electrode: Porcine Liver Slice
Conventional RF: Current Density
tumorCurrent density=1/r 4
Conventional RF: Current Density
tumorCurrent density=1/r 4
vessel
Vessels as cause of RF failures
• Lu DS, RSNA 2000
• Gillams AR, Lees W. RSNA 1999, 2000
Better RF Lesion Size/Shape with Vascular Occlusion
• Bodie AW, Cancer Res 1986
• Goldberg SN, Radiology, JVIR 1998
• Patterson EJ, Ann Surg 1998
• Chinn SB, Lee FT, AJR 2001
Decreased local recurrence (19%) of HCC with bland vascular occlusion
• Rossi S, Garbagnati F, Lencioni R, et al. Radiology 2000;217
RF ablation+chemoembolization:Rationale
• Embo increases size, rounder
• Deposits chemo in tumor, EDGES!
• RF increases dwell time of chemo
• Need long term results
RF + Chembo: RSNA 2001
• Yamakado K
• Pereira P
Good local control of large HCC
Chemoembolization + RF ablation
Post Chemoembolization Post Chembo+RF
Pre-treatment Post chembo+RF
Microwave Coagulation Therapy
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Last Updated: Dec. 10, 1999
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Microwave Coagulation Therapy
• Used in Japan for >10 years
• No system currently available in the USA
• Microwave “field” causes tissue heating
• Net effect is much like RF
generatorCurrent drop 1/r4
Heating drop 1/r2
RF ablation
generator
MCT ablation
No grounding pads necessary
RF ablation
Microwave
Active zone
Several mm’s
2 cm
Microwave Coagulation Therapy
Microwave vs RF
• Microwave: Hotter, possibly faster, multiple probes, no ground pads. No USA experience
• RF: Available, robust technology, increasing lesion size
Microwave vs RF
RF
MW
Immediate 48o 4 Weeks
MW vs. RF
48 Hours 4 Weeks
RF
MW
Hepatic Cryoablation• Very powerful local ablation technique• Multiple probes can be used together to
ablate a tumor of virtually any size• Freezes tissue to app. -150 degrees C.• Tissue death due to cellular rupture,
vascular occlusion
Cryoablation of liver tumors
• First focal tumor ablation technology
• Performed clinically since the early 1960’s
• Combined with IOUS in 1980’s (Onik)
Courtesy of G. Onik, MD
In era of RF, is cryo still needed?
• Very powerful. Multiple probes make a large iceball in a short period of time, can ablate up to large vessels.
Precryo POD 5 4 months post
In era of RF, is cryo still needed?
• Very powerful. Multiple probes make a large iceball in a short period of time, can ablate adjacent to large vessels.
• Low local recurrence rates
Cryoablation: Local Recurrence
• Deaconess (Kane) 5-year followup: 12%
• Wisconsin (Lee) 28 mo f/u: 9% Surgical margin recurrences 11%
RSNA 97
J GI Surg, 2001
• RF local recurrence 54% (Livraghi, Radiology 2001)
Hepatic Cryoablation
Cryoablation RF ablation
In era of RF, is cryo still needed?
• Very powerful. Multiple probes make a large iceball in a short period of time, can ablate adjacent to large vessels.
• Low local recurrence rates
• Visualize area being ablated
In era of RF, is cryo still needed?
• Very powerful. Multiple probes make a large iceball in a short period of time, can ablate up to large vessels.
• Low local recurrence rates (10% vs 40-50%
• Intraoperative: Don’t miss lesions>3mm
Precryo
Precryo POD 5
Liver cryosurgery
• Laparotomy
• Mini-laparotomy
• Percutaneous
Liver cryosurgery• Laparotomy
Monitored by IOUSCan detect tumors<3.0 mmOften combined with hepatic
resectionPlace probes to cover lesion +
margin with iceball
Cryosurgery at open laparotomy
• Need to mobilize liver for many tumor locations
• Can access virtually any lesion
IVC
IVC
Hepatic Cryosurgery: Minilaparotomy
• Use transvaginal US transducer
• Small incision, direct puncture of lesion
Laparoscopic vs. Minilaparotomy
Cryosurgery via minilaparotomy
Percutaneous CT-guided cryosurgery
Percutaneous Cryotherapy
PrePre
2 - 3mm probes 2 - 3mm probes
Immediate Post Immediate Post Courtesy Peter J. Littrup, MD
Balloon Protection
Courtesy Peter J. Littrup, MD
MRI guided Cryotherapy
Courtesy Stuart Silverman, MD
Cryoablation - complications (n=869 pooled world’s literature)
Mortality = 1.6%
Hemorrhage = 3.9%
Coagulopathy = 3.8%
ARF = 1.4%
Biloma 2.9%
Seifert. J Roy Coll Surg Edin 1998
Survival statistics for hepatic cryosurgery
Ref N Med. F/u (mo)
Disease-free survival (%)
Alive with disease (%)
Overall survival (%)
Ravikumar 32 24 34 28 62
Ravikumar 24 24 29 33.5 62.5
Onik 18 28.8 (mean) 22 67 89
Onik 50 18 (mean) 27 25 52
Zhou* 75 60, 120 7.3, 0
Zhou + 32 60, 120 48.8, 17.1
*HCC >5.0 cm+HCC <=5.0 cm
Cryoablation vs. Resection: Survival
Cryo Resection
N 63 60
3 yr. 60 51
5 yr. 44 36
10 yr. 19 8
1Kane, RSNA 19972Korpan, Ann Surg 1997: 225
(20)1
2
Followup of cryolesions
• “Hole” in liver where tumor was
• Enhancing rim for several months
• Eventual shrinkage and scarring
1 month post 4 months post 1 year post
Cryoablation: Complications (n=869)
• Mortality:1.6%
• Hemorrhage 3.9%
• Coagulopathy 3.8%
• Renal Failure 1.4%
• Biloma 2.9%
Seifert, J Royal Coll Surg 1998
Summary:Chemoembolization
• Used alone for palliation of unresectable/unablatable tumor
• Powerful when used in combination with RF
Summary: Microwave
• Theoretical advantages over RF(hotter, faster, multiple probes)
• Extensive experience in Asia, little in USA
• Awaiting optimization of technology
Summary: Cryoablation
• Very powerful, easy to see (CT,US,MRI)
• Generally used at surgery, emerging percutaneous applications
• Probably few more complications than thermal ablation