[Laser-induced thermotherapy (LITT) for liver metastasis in an open 0.2T MRI].
OBJECTIVE
To test the feasibility and safety of the laser-induced thermotherapy (LITT) for liver metastases in open MR imaging system operating at 0.2 Tesla.


METHODS
Laser therapy using the Nd:YAG laser was performed on 25 patients with a total of 41 liver metastases. An open low-field MRI scanner was used for puncture, positioning of the laser applicator, and monitoring the therapy. A true FISP sequence was used to track the puncture in close to real-time. Localization diagnostics and temperature monitoring were aided by T1-weighted gradient echo sequences in the breath-holding technique. In the first follow up after 24-48 hours, a contrast-enhanced T1-weighted gradient-echo sequence was performed in an MRI scanner at 1.5T. The pre-, intra- and postinterventional volumes of the liver metastases as well as the thermolesions and the thermonecroses were determined.


RESULTS
LITT in an open MRI system was technically feasible in all patients with no clinically relevant complications. The mean volumes of the thermolesions measured during intervention in low-field MRI were lower than the volumes of the thermonecroses measured after intervention in high-field MRI.


CONCLUSIONS
The technique presented here of laser-induced thermotherapy for liver metastases in an open MRI system is technically feasible and safe.
Reither
K
K
Abteilung für Radiologie und Nuklearmedizin, Universitätsklinikum Benjamin Franklin, Freien Universität Berlin. reither@cipmail.ukbf.fu-berlin.de
Wacker
F
F
Ritz
J P
JP
Isbert
C
C
Germer
C T
CT
Roggan
A
A
Wendt
M
M
Wolf
K J
KJ
D000368:Aged; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D053685:Laser Therapy; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary* / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000628:therapy