MRI-guided ultrasound inferior for certain myomas

Magnetic resonance-guided focused ultrasound surgery (MRgFUS), which is the least invasive surgical method for treating uterine myomas, is not ideal for type 3 high-intensity myomas. That's the case because the treated area ratio immediately after the procedure is small compared with that for type 1 and 2 myomas, and the subsequent volume change is unfavorable, according to the results of a prospective study from Japan.

The authors of the study followed 48 myomas in 35 women with MR images for 6 months after MRgFUS and followed 23 myomas in 17 women for 12 months after MRgFUS.

They found that while some type 1 and 2 myomas had reduced perfused volume 6 months after the procedure, all type 3 myomas showed increased perfused volume at 6 months post-MRgFUS, indicating, as has been previously suggested, that type 3 myoma cells naturally resist focused ultrasound energy and heating effects.

Funaki K, Fukunishi H, Funaki T, et al. Mid-term outcome of magnetic resonance-guided focused ultrasound surgery for uterine myomas: from six to twelve months after volume reduction. J Minim Invasive Gynecol. 2007;14:616-621.