1. Dr SH Chok Department of Surgery Ruttonjee & Tang Shiu Kin Hospitals
Joint Hospital Surgical Grand Round Radiofrequency Ablation for the management of liver tumours
Dr SH Chok
Department of Surgery
Ruttonjee & Tang Shiu Kin Hospitals

2. Introduction
Hepatocellular carcinoma (HCC) is one of the most common solid tumours
Estimated incidence ~ 1 million worldwide
Surgical resection offers only hope of cure
Only ~15% of patients with HCC suitable for resection
Multifocal disease
Close proximity to major structures
Inadequate liver remnant reserve

3. Introduction
Liver is the second most common site for distant metastasis from solid tumours
Particularly from colorectal cancer (CRC)
~50% of patients with CRC will develop metastasis or local recurrence within 5 years after initial “curative” resection
Surgical resection result in 20-35% long-term survival
10-15% of patients are surgical candidate

4. Local ablative therapies
Percutaneous injection
Percutaneous ethanol injection (PEI)
Acetic acid/ hypertonic saline/ water
Radioactive agents/ chemotherapeutic agents
Thermal ablative therapies
Cryoablation
Laser-induced thermotherapy (LITT)
Microwave coagulation therapy (MCT)
Radiofrequency ablation (RFA)

5. Radiofrequency Ablation (RFA)
First described by Rossi et al in 1993
Utilising high-frequency (200kHz- 20MHz) alternating current applied via an electrode(s) placed within the tissue to generate ionic agitation
Change direction of the ions in cells
Creating localised frictional heat
Causes coagulative necrosis and tissue desiccation
(Strasberg et al. Curr Probl Surg 2003)

6. RFA – Procedure
(Radiotherapeutics, Boston Scientific INC)

7. RFA Indications: Contraindications:
Unresectable tumours (primary/ secondary)
Multiple lesions ( 3)
Diameter ( 5cm)
Contraindications:
Coagulopathy
Gross ascites (for percutaneous route)
Difficult position (for percutaneous route)
Near major structures (e.g. bile duct)
Extrahepatic diseases
(Lau et al. Annals of Surgery 2003)

8. RFA – New indications Bridge therapy Salvage procedure
Pre-liver transplantation
(Pulvirenti et al. Transplantation Proceedings 2001)
Salvage procedure
Intra-operative bilobar disease
Resection + RFA
(Strasberg et al. Curr Probl Surg 2003)

9. RFA - Complications Overall incidence: 0- 12% Abscess formation
Bleeding
Bile leakage
Bile duct stricture
Liver failure
Grounding pad burn
Acute renal failure
Mortality: 0- 1%
(Seidenfeld et al. J Am Coll Surg 2002)

10. RFA - Specific consideration
“Heat sink” effect
Tumours situated near the major vessels may not have adequate ablation
Need longer period of ablation
Pringle maneuver
More uniform and faster ablation but increased chance of portal vein thrombosis
Generally not recommended
Margin
Margin of ablation is difficult to assess
Imaging (Pre-op/ Intra-op)

11. RFA – Method of delivery
Percutaneous, laparoscopic or open surgery
Prospective, non-randomised study
Study period: March April 2001
45 patients with unresectable liver tumours were recruited
HCC/ metastatic tumours: 11/ 34
Median follow-up: 12 months
(BW Kuvshinoff & DM Ota. Surgery 2002)

12. RFA – Method of delivery
Months
(BW Kuvshinoff & DM Ota. Surgery 2002)

13. Comparative interventions
MEDLINE search from 1966 – 2003
Keywords: RFA, liver tumours
RFA Vs.
Percutaneous ethanol injection (PEI) 
Cryoablation 
Microwave coagulation therapy (MCT) 
Hepatic artery infusion chemotherapy/ TACE 
Laser-induced thermotherapy (LITT) 

14. RFA vs PEI RCT, Study period: Dec 1996- Nov 1999
HCC,  3 lesions,  3 cm, percutaneous route
All patients had Child A/ B cirrhosis
Mean follow-up: 16.3  5.1 months
RFA
PEI
P-value
Number of patients (tumour nodules)
40 (54)
40 (61)
n.s.
Mean number of sessions to achieve complete ablation
1.3
3.3
<0.01
Complete ablative response (%)
91%
85%
Local recurrence after complete ablation (15 months median FU) 4%
17%
0.05
(Lencioni et al. Radiology 1999)

15. RFA vs Cryoablation Prospective, non-randomised study
Study period: Jan March 1998
Mean follow-up period: 15 months
HCC and metastatic tumours (41:105)
Laparotomy with IOUS
RFA
Cryoablation
P-value
Number of patients (tumour nodules)
92 (138)
54 (88) --
Local recurrence (% tumour nodules)
2.2
13.6
0.01
Complications (%)
3.3
40.7
<0.001
Death (number of patients) 1
(Pearson et al. Am J Surg 1999)

16. RFA vs MCT RCT, Study period: March 1999- Oct 2000
HCC,  4 cm,  3 lesions, percutaneous route
All patients had Child A cirrhosis
Follow-up period: 6-27 (18) months
RFA
MCT
P-value
Number of patients (tumour nodules)
36 (48)
36 (46) --
Complete ablative response (%) 96 89
n.s.
Local recurrence (%) 1 year/ 2 year
4/ 12
10/ 24
Complications (%) 3 11
(Shibata et al. Vascular and Interventional Radiology. 2002)

17. RFA vs TACE Retrospective, Study period: 1996- 1999
Multi-focal HCC, all had child A cirrhosis
Follow-up period: months
Percutanous route
RFA
TACE
P-value
Number of patients (tumour nodules)
10 (37)
10 (40) --
Complete control of tumour growth (%) 50 30
n.s.
Complications
Deaths 2 4
0.07
<0.05
(Livraghi et al. Radiology 2002)

18. RFA for metastatic liver tumours
Case series, unresectable colorectal liver metastases
All received surgery for primary tumours
Percutaneous route
Studies N
Extent of ablation (%)
Hepatic relapse (%)
Survival (year)
Complication
(Mortality)
Rossi et al. * 14
100 64
0 (14%)
Solbiati et al. ‖ 52 25 --
(Rossi et al.* Am J Roentgenol 1998, Solbiati et al.‖ Radiology 1997)

19. Summary
Merits of local ablative therapies are to preserve maximal amount of normal liver parenchyma and destroy the tumour in-situ
RFA is a safe and effective procedure
Most of the reported series were done under percutaneous route
Small sample size, short follow-up period
Heterogeneity of different studies

20. Questions to answer Technical consideration (mode of delivery)
Maximal tolerance of RFA
Salvage procedure
Role in primary treatment for resectable tumours ?
Need more studies to validate its clinical use in unresectable / resectable liver tumours

21. RFA – Bridge therapy Retrospective study
14 cirrhotic patients with small HCC ( 3.5cm)
RFA prior to transplanatation
Median follow-up: 16 months
Histology of the explant:
complete necrosis: 71%
incomplete necrosis: 29%
tumour satellites < 1cm from main tumour: 57%
No complication/ death/ recurrence

22. RFA – Survival rates for unresectable colorectal liver cancer
Survival time (years)
Solbiati et al. ‖
Stage IV disease (%) * 1 92
38.4 2 56
17.7 3 32
10.0 4 --
6.6 5
4.7
(Solbiati et al.‖ Radiology 1997, SEER US 2002*)