Ex vivo evaluation of novel miniaturized laser-induced interstitial thermotherapy applicators for effective small-volume tissue ablation

RATIONALE AND OBJECTIVES. For effective small-volume tissue ablation in cli nical and experimental settings, smaller laser-induced interstitial thermot herapy (LITT) applicator designs are required. The aim of this study was to compare the ablation properties of recently developed ultrasmall and small to standard LITT applicators. METHODS. Laser-induced interstitial thermotherapy was performed on liver sa mples using ultrasmall, small, and standard LITT applicators. Thermotherapy was monitored by magnetic resonance imaging, and lesion sizes were measure d for each image. True lesion sizes were then determined macroscopically an d by histology, RESULTS. For continuous laser application over 5 minutes, maximum power set tings were 5 W for the ultrasmall and small applicators and 10 W for the st andard applicator. Given identical LITT settings, lesion volume measured by magnetic resonance imaging was significantly larger and histological tissu e damage was more severe with the ultrasmall and small applicators than wit h the standard applicator, CONCLUSIONS, Small and ultrasmall LITT applicators can be used for effectiv e tissue ablation of small target volumes in experimental and clinical appl ications.