title: Magnetic resonance imaging-guided volumetric ablation of symptomatic leiomyomata: correlation of imaging with histology.
abstract: OBJECTIVE
  To describe the preliminary safety and accuracy of a magnetic resonance (MR) imaging-guided high-intensity-focused ultrasound (HIFU) system employing new technical developments, including ablation control via volumetric thermal feedback, for the treatment of uterine leiomyomata with histopathologic correlation.
  
  
  METHODS
  In this phase I clinical trial, 11 women underwent MR-guided HIFU ablation (Sonalleve 1.5T; Philips Medical Systems, Vantaa, Finland), followed by hysterectomy within 30 days. Adverse events, imaging findings, and pathologic confirmation of ablation were assessed. The relationship between MR imaging findings, thermal dose estimates, and pathology and HIFU spatial accuracy were assessed using Bland-Altman analyses and intraclass correlations.
  
  
  RESULTS
  There were 12 leiomyomata treated. No serious adverse events were observed. Two subjects decided against having hysterectomy and withdrew from the study before surgery. Of 11 women, 9 underwent hysterectomy; all leiomyomata demonstrated treatment in the expected location. A mean ablation volume of 6.92 cm(3) ± 10.7 was observed at histopathologic examination. No significant differences between MR imaging nonperfused volumes, thermal dose estimates, and histopathology ablation volumes were observed (P > .05). Mean misregistration values perpendicular to the ultrasound beam axis were 0.8 mm ± 1.2 in feet-head direction and 0.1 mm ± 1.0 in and left-right direction and -0.7 mm ± 3.1 along the axis.
  
  
  CONCLUSIONS
  Safe, accurate ablation of uterine leiomyomata was achieved with an MR-guided HIFU system with novel treatment monitoring capabilities, including ablation control via volumetric thermal feedback.
authors.affiliation: Radiology and Imaging Sciences, NIH Center for Interventional Oncology, Bethesda, MD 20892, USA. VenkatesanA@cc.nih.gov
authors.forename: Aradhana M
authors.initials: AM
authors.lastname: Venkatesan
authors.forename: Ari
authors.initials: A
authors.lastname: Partanen
authors.forename: Tajana Klepac
authors.initials: TK
authors.lastname: Pulanic
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Dreher
authors.forename: John
authors.initials: J
authors.lastname: Fischer
authors.forename: Robert K
authors.initials: RK
authors.lastname: Zurawin
authors.forename: Raja
authors.initials: R
authors.lastname: Muthupillai
authors.forename: Sham
authors.initials: S
authors.lastname: Sokka
authors.forename: Heikki J
authors.initials: HJ
authors.lastname: Nieminen
authors.forename: Ninet
authors.initials: N
authors.lastname: Sinaii
authors.forename: Maria
authors.initials: M
authors.lastname: Merino
authors.forename: Bradford J
authors.initials: BJ
authors.lastname: Wood
authors.forename: Pamela
authors.initials: P
authors.lastname: Stratton
mesh_terms: D000328:Adult; D005260:Female; D057086:High-Intensity Focused Ultrasound Ablation / Q000009:adverse effects; D006801:Humans; D007044:Hysterectomy; D007889:Leiomyoma / Q000473:pathology / Q000601:surgery*; D053783:Magnetic Resonance Imaging, Interventional; D008396:Maryland; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013781:Texas; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden; D014594:Uterine Neoplasms / Q000473:pathology / Q000601:surgery*