[MRI-assisted thermometry for regional hyperthermia and interstitial laser thermotherapy]. / MRT-gestützte Thermometrie in der regionalen Tiefenhyperthermie und interstitiellen Laserthermotherapie.

PURPOSE: To demonstrate the potential of quantitative MRI-assisted thermometry for the treatment of tumor patients with regional hyperthermia (RHT) and interstitial laser thermotherapy (ILTT). METHODS: Two patients and seven tissue samples were investigated using the T1-relaxation time and the chemical shift of the proton resonance frequency (PRF) as temperature sensitive MRI-parameters at 0.2 and 1.5 T. Thermotherapy was applied using either a dedicated MRI-hyperthermia hybrid system or a temperature controlled laser with 830 nm. RESULTS: Both patients were treated successfully showing clinical benefit. T1 and PRF are depending on the applied thermotherapy method and on the MR-system suitable for MRI-assisted thermometry. The clinical application based on phantom results is not necessarily adequate. CONCLUSION: Clinical application and phantom experiments of RHT and ILTT show the potential of MRI-assisted thermometry for further improvement of both minimal invasive thermotherapy methods. Further investigations concerning optimization of the MRI-techniques, the influence of perfusion or the determination of threshold values are necessary.