title: Laser-induced thermotherapy of malignant liver tumors: general principals, equipment(s), procedure(s)--side effects, complications and results.
abstract: OBJECTIVE
  To prospectively evaluate the therapeutic potential of MR-guided and ultrasound-guided laser-induced thermotherapy (LITT) in patients with liver metastases and oligonodular hepatocellular carcinoma (HCC).
  
  
  METHODS
  Between June 1993 and June 2000 a total of 1608 LITT sessions was performed to treat 1914 lesions in 676 consecutive patients. The Nd-YAG laser fiber was introduced with a percutaneously positioned cooled application set. Qualitative and quantitative ultrasound and magnetic resonance (MR) parameters, as well as clinical data were evaluated.
  
  
  RESULTS
  All patients tolerated the procedure well under local anesthesia; no relevant clinical complications were observed. The mean laser power was 25 W and the mean duration was 25 min. MR proved to be superior over computed tomography and ultrasound due the thermosensitivity of the MR sequences allowing a better visualization of the volume of laser-induced changes and their relation to the neighboring geographical structures. The ultrasound-guided LITT should be restricted for patients with contraindications for MR imaging monitoring and for selected patients with low diameter oligonodular HCC. In 95% of cases, we achieved a complete necrosis of the tumor and a 5-mm safety margin, resulting in a complete destruction of the tumor without local recurrences. Mean survival in this group was 35 months (calculated with the Kaplan-Meier method).
  
  
  CONCLUSIONS
  MR-guided, or ultrasound-guided, LITT appears to be a safe and effective treatment protocol for liver metastases and oligonodular HCC.
authors.affiliation: Department of Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany. t.vogl@em.uni.frankfurt.de
authors.forename: T J
authors.initials: TJ
authors.lastname: Vogl
authors.forename: K
authors.initials: K
authors.lastname: Eichler
authors.forename: R
authors.initials: R
authors.lastname: Straub
authors.forename: K
authors.initials: K
authors.lastname: Engelmann
authors.forename: S
authors.initials: S
authors.lastname: Zangos
authors.forename: D
authors.initials: D
authors.lastname: Woitaschek
authors.forename: M
authors.initials: M
authors.lastname: Böttger
authors.forename: M G
authors.initials: MG
authors.lastname: Mack
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D006979:Hyperthermia, Induced / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D053685:Laser Therapy; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary / Q000628:therapy*; D018084:Ultrasonography, Interventional