Comparison of the Therapeutic Efficacy of Non-touch Microwave Ablation, Tumor-puncture Microwave Ablation and Surgical Resection for Subcapsular Hepatocellular Carcinoma

This single-center prospective observational cohort study will be conducted at the First Hospital of Jilin University. The study aims to evaluate and compare the therapeutic efficacy, safety, and long-term clinical outcomes of three treatment modalities, including no-touch microwave ablation, tumor-puncture microwave ablation, and surgical resection, in patients with subcapsular hepatocellular carcinoma (HCC). The study will compare local tumor control, recurrence patterns, treatment-related complications, and survival outcomes among the three groups, providing clinical evidence for individualized treatment selection and optimizing long-term management strategies for patients with subcapsular HCC. The study population will consist of patients with a confirmed diagnosis of hepatocellular carcinoma. The diagnosis of HCC will be based on the practice guidelines of the American Association for the Study of Liver Diseases (AASLD). The definition of subcapsular hepatocellular carcinoma will follow previously published criteria, in which the shortest distance between the tumor margin and the liver capsule is ≤3 mm, as confirmed by imaging examinations including ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI). All enrolled patients will undergo comprehensive pre-treatment evaluations according to standard clinical practice, including routine blood tests, liver and renal function tests, coagulation assessment, serum alpha-fetoprotein (AFP) measurement, conventional ultrasound combined with contrast-enhanced ultrasound, and contrast-enhanced CT or MRI. These examinations will be used to assess tumor characteristics, hepatic functional reserve, and overall physical condition. Treatment strategies will be determined by a multidisciplinary liver cancer team based on clinical evaluation and patient-specific factors. All microwave ablation procedures will be performed by experienced interventional ultrasound physicians with more than 10 years of experience in microwave ablation therapy. During the study period, treatment responses and prognostic outcomes will be evaluated through follow-up assessments. Short-term follow-up data will include hospitalization duration and the incidence of postoperative complications, including hemorrhage, infection, needle tract seeding, thermal injury to perihepatic structures, liver failure, and ascites. Long-term therapeutic outcomes will be evaluated according to the following criteria: 1. Local tumor control rate: Patients will undergo regular imaging follow-up to evaluate local tumor recurrence. Local recurrence will be defined as the appearance of viable tumor lesions within or adjacent to the ablation zone in the microwave ablation groups, or recurrence near the surgical resection margin in the surgical resection group. Local tumor progression (LTP) will be defined as the development of new tumor lesions within or along the margin of the ablation zone after complete ablation in the microwave ablation groups, or the appearance of new tumor lesions adjacent to the surgical resection margin during imaging follow-up in the surgical resection group. 2. Disease-free survival (DFS): DFS will be defined as the time interval from completion of treatment to tumor recurrence, metastasis, or death. It will be used to evaluate the duration of disease-free status after treatment. 3. Overall survival (OS): OS will be defined as the time interval from completion of treatment to death from any cause or the date of the last follow-up. It will be used to evaluate the impact of different treatment modalities on overall survival outcomes. Kaplan-Meier survival analysis will be performed to evaluate LTP, OS, and DFS. The log-rank test will be used to compare differences among treatment groups. Univariate and multivariate Cox proportional hazards regression models will be applied to identify independent prognostic factors associated with treatment outcomes. This study will compare OS, DFS, and local tumor progression rates among the three treatment modalities to evaluate the relationship between different treatment strategies and long-term clinical outcomes. Furthermore, recurrence patterns, recurrence locations, and subsequent treatment strategies after recurrence will be analyzed to provide evidence-based information for optimizing individualized treatment strategies for patients with subcapsular HCC.

• Time to tumor recurrence [Time frame: Up to 2 years after treatment]
• Pattern of tumor recurrence [Time frame: Up to 2 years after treatment]
• Treatment modality after tumor recurrence [Time frame: Up to 2 years after treatment]