High Intensity Focused Ultrasound (HIFU) for Liver Tumour

1. High Intensity Focused Ultrasound (HIFU) for Liver Tumour Dr Dai Wing Chiu Queen Mary Hospital

2. Background • Treatment options for hepatocellular carcinoma • Resection • Liver transplantation • Local ablative therapy • Transarterial chemoembolization (TACE)

3. Local Ablation Therapy • The first description of percutaneous ethanol injection (PEI) Liveraghi T et al. Radiology 1986 • Thermal techniques were first performed in the liver using single bare tip neodymium yttrium aluminium garnet (NdYAG) laser fibres Steger A et al. BMJ 1989 • Five thermal techniques • Radiofrequency ablation • Laser • Microwave • Cryotherapy • High intensity focused ultrasound (HIFU)

4. High Intensity Focused Ultrasound • The first investigation of HIFU for non-invasive ablation were reported in the early 1940s • Animal studies

5. High Intensity Focused Ultrasound • Ultrasound • High intensity • 1000W/cm2 to 25000W/cm2 • Focus

6. Heating effect Cavitation Mechanism Ultrasound

7. ‘Lesion’ of coagulation necrosis at focus Target organ (e.g. liver) Transducer Tumor Skin Undamaged tissue surrounding focus

8. HIFU service for HCC started in Oct 2006 thanks to donation of the USG-guided HIFU system by Chongqing Haifu Co. HIFU at Queen Mary Hospital

9. HIFU

10. HIFU – Current evidence • 50 consecutive patients with stage IVA HCC • Group 1 (n=26) - TACE alone • Group 2 (n=24) – TACE with HIFU performed 2-4 weeks afterwards • Tumours size 4-14cm (mean 10.5cm) • FU 3-24 months (mean 8 months) F Wu et al. Radiology 2005

11. HIFU – Current evidence • 55 patients with HCC • Prospective, non-randomized clinical trial • Tumour size 4-14cm in diameter (mean 8.14cm) • Serum AFP returned to normal level in 34% of patient • Overall survival rates at 6, 12 and 18 months were 86.1%, 61.5% and 35.3%, respectively • Survival rates were significantly higher in patients in stage II than those in stage IIIA (p=0.0132) and in stage IIIC (p=0.0265). Wu F et al. Ann Surg Oncol 2004

12. HIFU at Queen Mary Hospital • From October 2006 to April 2008, totally 41 patients with unresectable HCC received HIFU treatment • Initial 21 patients received HIFU with transarterial embolization (TAE) (Period 1), and subsequent 20 patients received HIFU without TAE (Period 2)

13. Demographic and Clinical Data

14. Tumor and Treatment Data

15. Results a: Complete ablation rate in terms of number of patients b: Complete ablation rate in terms of number of tumor nodules

16. 100 90 80 P=0.074 70 Overall Survival 60 50 Period 1 40 Period 2 30 20 10 0 0 10 20 Months Overall Survival • Short-term survival outcome between the two groups (period 1 vs. period 2) were similar (86.5% vs. 79% at 1 year, P = 0.074) Period 1 Period 2

17. Indications for HIFU at QMH • Unresectable primary or recurrent HCC (inadequate liver function, multifocal HCC, proximity to major vessels) • Curative intent • Tumor size < 10 cm • < 3 tumor nodules • No venous invasion • No extrahepatic metastasis • General condition fit for general anesthesia

18. Discussion • Its application as a non-invasive surgical tool is still in its infancy • Limitations and challenges • Indications • Limited evidence