Interstitial thermotherapy for liver tumours: Studies of different fibres and radiation characteristics

Abstract

Interstitial thermal laser destruction is an attractive modality for treatment of primary and metastatic liver tumours. Using a bare fibre the volume of tissue destroyed is limited and repeated therapy is necessary. This is time consuming and it is not easy to be certain that the entire lesion is treated. We have investigated the use of a modified laser fibre. The tip of this fibre is provided with a cap made of quartz glass emitting the laser radiation laterally and circumferentially. The necrosis had an ellipsoid shape with a size amounting to 2.1±0.63 cm on 1.6±0.58 cm using 3 W power with an exposure of 600s. These lesions were much larger than the necrosis induced by bare laser fibre photocoagulation which, at most, amounts to 1.2±0.46 cm using 1.5W power for 600s. These sizes were very suitable for using the method clinically. However, the lesions were not always reproducible due to damage of the fibre during long time exposure. We conclude that further research is necessary to increase the reliability of the fibre before clinical application for therapy of liver metastasis.