Joint Hospital Surgical Grand Round Radiofrequency Ablation for the management of liver tumours

1. Joint Hospital Surgical Grand RoundRadiofrequency 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: • 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 • 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 1999- 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

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 (Lencioni et al. Radiology 1999)

15. RFA vs Cryoablation • Prospective, non-randomised study • Study period: Jan 1992- March 1998 • Mean follow-up period: 15 months • HCC and metastatic tumours (41:105) • Laparotomy with IOUS (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 (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: 12- 36 months • Percutanous route (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 (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 (Solbiati et al.‖Radiology 1997, SEER US 2002*)