Mid-term outcome of magnetic resonance-guided focused ultrasound surgery for uterine myomas: from six to twelve months after volume reduction.
OBJECTIVE
To clarify the volume change ratio of uterine myomas treated with magnetic resonance-guided focused ultrasound surgery (MRgFUS), in relation to the signal intensity of T(2)-weighted magnetic resonance (MR) images.


METHODS
Prospective study (Canadian Task Force classification II-3).


METHODS
Department of Gynecology, Shinsuma General Hospital, Kobe, Japan.


METHODS
Forty-eight myomas in 35 patients were followed up with MR images 6 months after MRgFUS, and 23 myomas in 17 patients were followed up 12 months after MRgFUS. Before treatment, the myomas were classified into 3 types on the basis of the signal intensity of T(2)-weighted MR images as follows: Type 1, low intensity; type 2, intermediate intensity; type 3, high intensity.


METHODS
Thermal ablation therapy was performed with an MRgFUS system (ExAblate 2000).


RESULTS
MRgFUS produced a greater volume reduction in type 1 and type 2 myomas than in type 3 myomas. Nonperfused areas always diminished in the period after MRgFUS; however, the volume change was affected by the volume change ratio of perfused areas inside the treated myomas.


CONCLUSIONS
At present, type 3 myomas should be exempted from the application of MRgFUS, because the nonperfused ratio immediately after the procedure was small compared with that in type 1 and type 2 myomas, and the subsequent volume change was unfavorable.
Funaki
Kaoru
K
Department of Gynecology, Shinsuma Hospital, Kobe, Hyogo, Japan. funakikaoru@ybb.ne.jp
Fukunishi
Hidenobu
H
Funaki
Tsuyoshi
T
Kawakami
Chihiro
C
D000328:Adult; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D018231:Leiomyomatosis / Q000628:therapy*; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D008875:Middle Aged; D013817:Thermography; D016896:Treatment Outcome; D014464:Ultrasonic Therapy / Q000379:methods*; D014594:Uterine Neoplasms / Q000628:therapy*