Microwave Ablation for the Treatment of Malignant Liver Tumors Closed to Intrahepatic Vessels

Liver cancer including primary hepatocellular carcinoma (HCC) and metastatic liver cancers is one the most common malignancies in the world. Over 10000 new cases per year are diagnosed in Taiwan. Despite the many treatment options, the prognosis of HCC remains dismal. More than 8000 people died of this cancer every year in Taiwan. A majority (70% to 85%) of patients present with advanced or unresectable disease. In contrast, small liver cancers can be cured with an appreciable frequency. Five-year disease-free survival exceeding 50% has been reported for surgical resection, and for the inoperable patients who do not have vascular invasion or extrahepatic spread. Radiofrequency ablation (RFA) is recommended as an alternative curative therapy. However, the main drawback of RFA is its limitation to tumor size and location. The tumors larger than 5 cm in diameter or located adjacent to vessels, could not be ablated completely sometimes. Microwave ablation (MWA) can ablate tumor by higher temperature than RFA, so is supposed not to be diminished by adjacent vessels.

Several pre-clinical studies have already demonstrated microwave ablation (MWA) is a safe and effective treatment for live cancers. The system (Emprint Microwave Ablation system) with 2.45 GHz microwave generator the investigators will use has been approved as safe by the European Union (EU) in 2009 and received Food and Drug Administration (FDA) approval in 2014. However, there are still few experiences in using MWA for tumor ablation in Taiwan. In this study, we will perform MWA for 40 inoperable patients with liver cancers adjacent to vessels who are suitable to receive radiofrequency ablation (RFA) in our hospital. The investigators will evaluate the potential side effect and ablate effect of tumors by abdominal computed tomography (CT) or magnetic resonance imaging (MRI), and the investigators will also follow-up this patients for 1 years to evaluate the overall survival and local recurrence rate. The investigators will appraisal the clinical feasibility and advantage of the system by this study.

Eligibility Criteria:
Inclusion Criteria:

Patients must meet all of the following inclusion criteria to be eligible for this study:

1. Unsuitable for surgical resection but local ablation is indicated, however, the distance between tumour and vessels is smaller than 1 cm.
2. Have at least one, but less than or equal to 3 tumors.
3. Each tumor must be ≤ 5 cm in diameter.
4. Child-Pugh class A-B.
5. Eastern Cooperative Oncology Group (ECOG) score of 0-1.
6. American Society of Anaesthesiologists (ASA) score ≤ 3.
7. Adequate bone marrow and liver function (1). Platelet count ≥ 100 K/Μl(2). Total bilirubin ≦ 2 mg/dL(3). alanine transaminase (ALT) and aspartate transaminase (AST) \< 5 x upper limit of normal (4). prothrombin time (PT)- international normalized ratio (INR) ≦ 2.0.
8. The disease status is not suitable to receive transarterial chemoembolization or other standard treatment.
9. Prior Informed Consent Form.
10. Life expectancy of at least 3 months.

Exclusion Criteria:

Patients presenting with any of the following will not be enrolled into this study:

1. Women who are pregnant or women of child-bearing potential who are not using an acceptable method of contraception.
2. Received treatment with an investigational agent/ procedure within 30 days prior to microwave ablation.
3. Patients who cannot tolerate radiofrequency ablation (RFA) procedure.
4. Known history of human immunodeficiency virus (HIV) infection.
5. Concurrent extrahepatic cancer.