Factors Predicting Complete Necrosis Rate after Ultrasound-Guided Percutaneous Laser Thermoablation of Small Hepatocellular Carcinoma Tumors in Cirrhotic Patients: A Multivariate Analysis

Purpose: To assess factors affecting the effectiveness of percutaneous laser ablation (PLA) under ultrasound (US) guidance in terms of complete ablation achievement. Material and Methods: The clinical records of 86 hepatocellular carcinoma (HCC) tumors (mean diameter 23.7 mm) in 60 cirrhotic patients (mean age 68.3 years; 36 males; 57 HCV+; 53 Child's class A, seven Child's class B) treated by means of PLA were reviewed. PLA was performed with a continuous-wave Nd:YAG laser by a single operator who positioned two to four 300-µm optic fibers advanced in 21-gauge needles into target lesions under US guidance. Triphasic computed tomography (CT) studies were used to verify treatment effectiveness 1 month after PLA completion. The association between characteristics of the lesion and outcome (complete or incomplete ablation) was evaluated by logistic regression, taking into account the following predictive factors: tumor size, pattern of growth (infiltrating or not) at imaging, location, first diagnosis of HCC (naïve tumors vs. non-naïve tumors), number of sessions (1 >1), total delivered energy, and years of treatment in 2001-2002 (first period) vs. 2003-2004 (second period). Results: Complete ablation was obtained in 62 nodules (72%). Statistically significant predictors of incomplete ablation after the first PLA course at both univariate and multivariate analysis included: infiltrating growth pattern (odds ratio (OR) 12.3, P