A comparative analysis of ablation zone size in cow liver tissue using 980-nm and 980/1470-nm diode lasers with conventional optical fiber (600 µm) at various power levels and exposure durations: An ex vivo experimental study

Hepatocellular carcinoma (HCC) and liver metastasis are leading causes of cancer-related morbidity and mortality worldwide. Laser Interstitial Thermal Therapy (LITT) is a promising minimally invasive ablation modality. However, its effectiveness is highly dependent on technical parameters such as wavelength, power, and exposure duration. This study aims to evaluate the effects of variations in wavelength, power, and exposure duration on the size of the ablation zone in liver tissue ex vivo and to compare the effectiveness of a single 980 nm laser with a combination of 980/1470 nm lasers. Ablation was performed on cow liver tissue using a conventional diode laser without cooling. The variables tested included wavelength (980 nm and 980/1470 nm), power (4-30 watts), and exposure duration (1-7 minutes). The size of the ablation zone was measured macroscopically and confirmed histologically. Statistical analysis was performed using ANOVA and post hoc tests. The combination of 980/1470 nm wavelengths produced a larger ablation zone than the single wavelength of 980 nm. A power of 30 watts and an exposure duration of 5 minutes were identified as the optimal configuration, resulting in the largest ablation area. Exposure durations longer than 5 minutes led to a reduction in the ablation zone size due to carbonization and thermal saturation effects. Histopathological results demonstrated consistency between the macroscopic changes and microscopic thermal necrosis. The combination of 980/1470 nm wavelengths significantly improves the effectiveness of laser ablation and has the potential to be an applicable approach for liver tumor ablation procedures, particularly in facilities without cooling systems.