Ultrasonographic guided laser-induced interstitial thermotherapy (LITT) of hepatic metastases

Abstract

Background: In patients with unresectable hepatic metastases or primary liver tumors therapeutic options are limited. Laser-induced thermotherapy could be a minimal invasive option for palliative treatment of hepatic metastasized tumors. Thereby, absorption of laser light energy induces denaturation of proteins and thermocoagulation of tumor cells. Methods: Laser coagulation was performed by using a neodymium-yttrium alum/n/urn garnet (Nd:YAG) laser (Dornier MediLas fibertom 4100) with a scattering-dome light emitter and a water-cooled application catheter (Somatex). On the basis of ex vivo experiments 36 patients with unresectable hepatic tumors (15 colorectal carcinomas, 7 pancreatic adenocarcinomas, 4 gastric carcinomas, 4 metastasized midgut carcinoids, 5 hepatocellular carcinomas, 1 cholangiocellular carcinoma) were treated with LII3. After local anesthesia and intravenous sedation with midazolam laser probes were placed percutaneously under ultrasonographic guidance. Up to 5 metastases were treated per session. Results: During laser light emission uitrasonographic imaging showed a marked signal enhancement that allowed estimation of the coagulation zone. Percutaneous LITT was performed without any side effects such as bleeding, infection or liver injury. The 30 day mortality was zero. Patients left the hospital within 3 days after LITT. A significant tumor reduction was demonstrated by abdominal CT or MRT. Conclusions: It can be concluded that percutaneous LITT can be safely performed under ultrasonngraphic guidance in patients with malignant liver tumors. LITI induces significant destruction of tumor mass as verified by abdominal CT or MRT.