Percutaneous interstitial thermotherapy for malignant liver tumors. Purpose

Purpose: Description of local ablative techniques such as laser-induced the rmotherapy (LITT) and radiofrequency ablation in the percutaneous interstit al thermotherapy for malignant liver tumors. Patients and Methods: MR-guide d LITT is currently performed by means of implantable percutaneous catheter systems. CT is used to control the insertion of the catheter. Irrigated ad ministration systems are available both for LITT and for radiofrequency the rapy. Results: At present LITT enables a local tumor control of 97.2% for l ocalized liver metastases without extrahepatic spreading patterns. In a gro up of 381 patients the average survival times were 45.7 months for patients with liver metastasis, 42.7 months for those with colorectal liver metasta ses, and 32 months for HCC tumors. The data for radiofrequency ablation con firm the high value for tumor control of hepatocellular carcinomas with poo rer results for liver metastases. Conclusions: Percutaneous, MR-guided LITT permits good tumor control of liver metastases smaller than 5 cm and less than 5 in number. For HCC, at present percutaneous injection of alcohol, ra diofrequency ablation, and LITT are equally effective.