Abstract: The aim of this study was to compare interstitial laser
thermotherapy with excision of a liver tumour. A dimethylhydrazine-induced
adenocarcinoma was implanted into the left lateral lobe of the rat liver, and
treatment was performed 8 days later. Rats were treated with resection of the
tumour-bearing lobe or underwent interstitial laser thermotherapy, which was
performed at a steady-state temperature of 46°C for 30 min, 3 mm from the
tumour margin. The incidence and extent of intraperitoneal spread was smaller
after laser thermotherapy than after resection, with no difference in local
control. Using inoculation of tumour cell suspensions into the lateral and the
median lobes of the liver simultaneously and treating the lateral lobe tumour
only, we found that laser thermotherapy reduced take and growth of the
untreated tumour in the median lobe indicating that laser thermotherapy may
induce immunologic effects. It is concluded that interstitial laser
thermotherapy reduces spread of liver tumour as compared to resection. It is
suggested that this can be at least partly explained by a laser-induced
immunologic effect.
