Chemoembolization,
Cryotherapy and
Microwave Thermotherapy
Fred 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
Mitomycin C
Adriamycin
Ethiodol
Contrast
Ivalon particles
100 mg
10 mg
50 mg
10 cc
8 cc
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
4
Current density=1/r
tumor
Conventional RF: Current Density
vessel
4
Current density=1/r
tumor
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
UW coach's son gets 10 days for
parrot's microwave death
Chad Alvarez will begin jail term on
Dec. 20
By Dennis Chaptman
of the Journal Sentinel staff
Last Updated: Dec. 10, 1999
Madison - The microwave-oven killing of Iago, a Quaker parrot owned
by a fraternity brother, landed Chad Alvarez two felony convictions and
a sentence of probation and
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
RF ablation
generator
4
Current drop 1/r
2
Heating drop 1/r
MCT ablation
generator
No grounding pads necessary
RF ablation
Active zone
Several mm’s
Microwave
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
RF
MW
48 Hours
4 Weeks
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 4050%
• Intraoperative: Don’t miss lesions>3mm
Precryo
Precryo
POD 5
Liver cryosurgery
• Laparotomy
• Mini-laparotomy
• Percutaneous
Liver cryosurgery
• Laparotomy
Monitored by IOUS
Can detect tumors<3.0 mm
Often combined with hepatic
resection
Place 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
Pre
2 - 3mm probes
Courtesy Peter J. Littrup, MD
Immediate Post
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%
ARF = 1.4%
Hemorrhage = 3.9%
Biloma 2.9%
Coagulopathy = 3.8%
Seifert. J Roy Coll Surg Edin 1998
Survival statistics for hepatic
cryosurgery
Ref
N
Med. F/u (mo)
Disease-free
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
Alive with
disease (%)
Overall
survival (%)
Cryoablation vs. Resection: Survival
1
Cryo
Resection
N
63
60
3 yr.
60
51
5 yr.
44 (20) 1
36
10 yr.
19
8
Kane, RSNA 1997
Korpan, Ann Surg 1997: 225
2
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