Magnetic resonance imaging-controlled laser-induced interstitial thermotherapy.
OBJECTIVE
Laser-induced interstitial thermotherapy (LITT) may become an attractive modality for minimally invasive tumor therapy. Magnetic resonance imaging (MRI) could be used to assist this procedure.


METHODS
A T1-weighted turbo fast low-angle shot (FLASH) sequence for on-line monitoring of the laser-influenced region (liver, muscle) was investigated. Sequence parameters were optimized for maximal image contrast. Magnetic resonance imaging-controlled LITT was performed in vitro, in vivo (rabbits), and in 8 human investigations (6 patients). Special laser applicators were used to establish a uniform laser light distribution.


RESULTS
With the MRI sequence used, the LITT region is visualized as a bright area outlined by a dark border. This dark border corresponds to an isotherm of 45 +/- 2 degrees C depending on the sequence parameters used.


CONCLUSIONS
With the T1-weighted turbo-FLASH sequence, MRI can be used for on-line monitoring of interstitial laser-induced thermotherapy in moving organs.
Gewiese
B
B
Department of Radiology, Klinikum Steglitz, Berlin, Germany.
Beuthan
J
J
Fobbe
F
F
Stiller
D
D
Müller
G
G
Böse-Landgraf
J
J
Wolf
K J
KJ
Deimling
M
M
D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D017075:Laser Coagulation; D008099:Liver / Q000601:surgery; D008113:Liver Neoplasms / Q000601:surgery; D008175:Lung Neoplasms / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009132:Muscles / Q000601:surgery; D010789:Phototherapy / Q000379:methods*; D011817:Rabbits; D012756:Sheep; D013552:Swine