Dosimetric Differences and Clinical Significance Analysis Between Body Gamma Knife and VMAT Radiotherapy for Primary Liver Cance

Inclusion Criteria: * Aged 18-75 years. * Clinically or pathologically confirmed primary liver cancer; unsuitable for or - refusing surgery, with single tumor diameter ≤5 cm and ≤5 nodules. * ECOG PS score 0-1. * Liver function: Child-Pugh grade A or B. * Prothrombin time (PT) \< 4 seconds above the normal control range. * No hepatic encephalopathy or moderate to large ascites. * Renal and cardiopulmonary function basically normal. * Gastroscopy findings: no severe esophageal varices or active peptic ulcer. * Hemoglobin ≥90 g/L, WBC ≥3.0×10⁹/L, neutrophil ≥1.5×10⁹/L, platelet ≥40×10⁹/L. * No obvious cachexia; life expectancy \> 3 months. * Not pregnant; no HIV or syphilis infection. * Able to understand the study and sign informed consent. Exclusion Criteria: * History of portal hypertension, esophageal variceal bleeding, or related conditions. * History of anti-RHCC treatment or spontaneous tumor rupture. * Postoperative pathology indicates metastatic cancer or other primary cancers. * Cerebrovascular accident within 6 months before enrollment. * Severe lung disease; serum creatinine \> 1.25×the upper normal limit. * Poorly controlled acute or active infection; severe mental illness. * Suspected systemic or local lymphadenopathy on imaging. * Pregnant or lactating women; presence of other serious underlying diseases. * Currently participating in other clinical trials; refusal to provide informed consent.