Laserinduced thermotherapy (LITT) - Energy and temperature determination for complete in-situ ablation of livermetastasis

摘要

The aim of this study was to determine the energy (J/mm~3 tumor volume) and temperature required for a complete in-situ-ablation of experimental liver tumors. Methods: LITT was performed in VX-2 tumor-bearing rabbits using Nd-YAG-Laser (1064nm) with a diffuser-tip applicator and a temperature feedback-system. The animals were randomized into 4 groups (n=20) that differed in the target temperature at the tumor border (45 deg C, 50 deg C, 55 deg C and 60 deg C). Histological examination was done at 0 h, 24 h, 96 h and 14 days after LITT. Results: The pretreatment tumor volume of 2191+-61 mm~3 was the same for all groups (p>0.05). Energy and temperature required and the rate of incomplete tumor-ablation (recurrences) are listed below (*=p<0.05, Kruskal-Wallis test. Conclusions: 1) To achieve complete in-situ-ablation under the given conditions, it is necessary to apply laser-energy of 3 J/mm~3 tumor volume. 2) A minimum temperature of 60 deg C on the tumor border presumed an application of 10 minutes.