title: Predicting the effect of gonadotropin-releasing hormone (GnRH) analogue treatment on uterine leiomyomas based on MR imaging.
abstract: OBJECTIVE
  To test the hypothesis that the simple assessment of signal intensity on T2-weighted MR images is predictive of the effect of hormonal treatment with gonadotropin-releasing hormone (GnRH) analogue.
  
  
  METHODS
  The correlation between T2-weighted MR imaging of uterine leiomyomas and histologic findings was evaluated using 85 leiomyomas from 62 females who underwent myomectomy or hysterectomy. We also correlated the pretreatment MR images features obtained in 110 women with 143 leiomyomas with the effect of GnRH analogue treatment. The size (length x width x depth) of the leiomyoma was evaluated before and at 6 months after treatment by ultrasound.
  
  
  RESULTS
  The proportion of leiomyoma cell fascicles and that of extracellular matrix affected signal intensities of uterine leiomyomas on T2-weighted MR images. The amount of extracellular matrix was predominant in hypointense leiomyomas on T2-weighted images, while diffuse intermediate signal leiomyomas were predominantly composed of leiomyoma cell fascicles. Marked degenerative changes were noted in leiomyomas with heterogenous hyperintensity. The homogeneously intermediate signal intensity leiomyomas showed significant size reduction after treatment (size ratio; posttreatment volume/pretreatment volume 0.29+/-0.11). The size ratio for the hypointense tumors was 0.82+/-0.14, and 0.82+/-0.18 for the heterogeneously hyperintense tumors. There was a significant difference in the response to treatment between the homogeneously intermediate signal intensity leiomyomas and the hypointense or heterogeneously hyperintense leiomyomas (both p<0.01).
  
  
  CONCLUSIONS
  Signal intensity on T2-weighted MR images depends on the amount of leiomyoma cell fascicles and extracellular matrix. Simple assessment of the MR signal intensity is useful in predicting the effect of GnRH analogue on uterine leiomyomas.
authors.affiliation: Department of Radiology, Kumamoto University School of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuno
authors.forename: Y
authors.initials: Y
authors.lastname: Yamashita
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: H
authors.initials: H
authors.lastname: Katabuchi
authors.forename: H
authors.initials: H
authors.lastname: Okamura
authors.forename: Y
authors.initials: Y
authors.lastname: Kitano
authors.forename: T
authors.initials: T
authors.lastname: Shimamura
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000627:therapeutic use*; D002064:Buserelin / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D018231:Leiomyomatosis / Q000188:drug therapy* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D011237:Predictive Value of Tests; D016896:Treatment Outcome; D014594:Uterine Neoplasms / Q000188:drug therapy* / Q000473:pathology
chemical_list: D018931:Antineoplastic Agents, Hormonal; D002064:Buserelin