[Early clinical experiences with MR-guided laser-induced thermotherapy (LITT) of liver metastases in preoperative care].

PURPOSE

To evaluate the LITT-induced changes with the aid of MRT and correlate these with histopathological findings.

MATERIAL AND METHODS

Five patients with solitary colorectal liver metastases were treated by means of MR-guided LITT before liver resection. Application time and energy of the Nd:YAG laser (1064 nm) was 10-20 minutes and 4.5-8.8 W. MRT monitoring during the LITT was carried out with temperature-sensitive T1 weighted sequences (FLASH-2-D, turbo FLASH). The extent of the induced necrosis as seen on MR was compared with the unfixed specimen and with the histopathological findings.

RESULTS

The extent of necrosis visible by MRT correlated with the histopathological findings with an accuracy of 95.3% +/- 4.2%. Following single treatments (three cases) the metastases suffered a reduction of 24%-55% of their original volume. In two patients a second application produced laser-induced necrosis of 78% and 98% of volume. In these two patients a temperature sound was used for measuring regional heating and showed an exact correlation with MR thermometry.

CONCLUSION

The results of pre-operative MR-guided LITT indicates the potential of this form of treatment for obtaining reproducible tumor necrosis of liver metastases.