Ex vivo evaluation of novel miniaturized laser-induced interstitial thermotherapy applicators for effective small-volume tissue ablation.
OBJECTIVE
For effective small-volume tissue ablation in clinical and experimental settings, smaller laser-induced interstitial thermotherapy (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 samples using ultrasmall, small, and standard LITT applicators. Thermotherapy was monitored by magnetic resonance imaging, and lesion sizes were measured for each image. True lesion sizes were then determined macroscopically and by histology.


RESULTS
For continuous laser application over 5 minutes, maximum power settings were 5 W for the ultrasmall and small applicators and 10 W for the standard applicator. Given identical LITT settings, lesion volume measured by magnetic resonance imaging was significantly larger and histological tissue damage was more severe with the ultrasmall and small applicators than with the standard applicator.


CONCLUSIONS
Small and ultrasmall LITT applicators can be used for effective tissue ablation of small target volumes in experimental and clinical applications.
Bremer
C
C
Institute for Clinical Radiology, University of Muenster, Germany. bremer@helix.mgh.harvard.edu
Kreft
G
G
Roggan
A
A
Filler
T
T
Reimer
P
P
D000818:Animals; D004867:Equipment Design; D006979:Hyperthermia, Induced / Q000295:instrumentation; D066298:In Vitro Techniques; D017075:Laser Coagulation / Q000295:instrumentation*; D008099:Liver / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008904:Miniaturization; D013552:Swine