title: Preliminary results of contrast-enhanced sonography in the evaluation of the response of uveal melanoma to gamma-knife radiosurgery.
abstract: OBJECTIVE
  Our aim was to prospectively analyze the use of contrast-enhanced ultrasound (CEUS) in the quantitative assessment of the response of uveal melanoma (UM) to gamma-knife radiosurgery (GKR), investigating whether changes in tumor vascularization precede thickness reduction, which on average occurs at 12 months after GKR.
  
  
  METHODS
  Ten patients with UM treated with GKR underwent sonography (US) and CEUS at baseline and at 3, 6, and 12 months after GKR. The transverse diameter, thickness, and quantitative parameters of the UM (ie, area under the curve in the wash-in phase, wash-in perfusion index, peak enhancement, and wash-in rate) were calculated by using dedicated software and compared by using Wilcoxon's signed-rank test.
  
  
  RESULTS
  The mean tumor thickness on US was significantly less at both 6 (6.6 mm) and 12 months after GKR (5.8 mm) than it was at baseline (8.3 mm; p < 0.05, both comparisons). Compared with baseline data, the median flow quantitative parameters on CEUS were significantly changed as follows: the peak enhancement (in arbitrary units [au]) at baseline was 5 × 10(6) ; 6 months after GKR, it was 2 × 10(1) (p < 0.05), and 12 months after GKR, it was 4 × 10(1) (p < 0.05). The wash-in rate (in au) at baseline was 1 × 10(6) ; 6 months after GKR, it was 2.1 (p < 0.05), and 12 months after GKR, it was 9.3 (p < 0.05). The wash-in perfusion index (in au) at baseline was 2 × 10(7) ; 6 months after GKR, it was 7 × 10(1) (p < 0.05), and 12 months after GKR, it was 1 × 10(2) (p < 0.05). The area under the curve during the wash-in phase (in au) at baseline was 1 × 10(8) ; 12 months after GKR, it was reduced to 6 × 10(2) (p < 0.05).
  
  
  CONCLUSIONS
  At 6 months after GKR, a reduction of tumor thickness, as detected on US, occurred in 6 of the 10 patients, whereas a reduction in all the quantitative parameters measured on CEUS occurred in all 10 patients. However, a larger population is needed to investigate whether CEUS could become the first-choice technique for monitoring the response of UM to GKR.
authors.affiliation: Department of Radiology, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Venturini
authors.affiliation: Department of Radiology, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Colantoni
authors.affiliation: Department of Ophthalmology, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Modorati
authors.affiliation: Department of Ophthalmology, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Maura
authors.initials: M
authors.lastname: Di Nicola
authors.affiliation: Department of Ophthalmology, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Colucci
authors.affiliation: Department of Radiology, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Agostini
authors.affiliation: Department of Neurosurgery, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Picozzi
authors.affiliation: Department of Radiology, San Raffaele Scientific Institute, Milan, Italy.|Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: De Cobelli
authors.affiliation: Vita-Salute San Raffaele University, Milan, Italy.|Department of Oncology, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Parmiani
authors.affiliation: Department of Neurosurgery, San Raffaele Scientific Institute, Milan, Italy.|Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Mortini
authors.affiliation: Department of Ophthalmology, San Raffaele Scientific Institute, Milan, Italy.|Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Bandello
authors.affiliation: Department of Radiology, San Raffaele Scientific Institute, Milan, Italy.|Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Del Maschio
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000601:surgery*; D008875:Middle Aged; D011446:Prospective Studies; D016634:Radiosurgery; D014463:Ultrasonography; D014602:Uvea / Q000000981:diagnostic imaging / Q000601:surgery; D014604:Uveal Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D000098943:Uveal Melanoma
chemical_list: D003287:Contrast Media
keywords: contrast-enhanced ultrasonography; gamma-knife radiosurgery; ultrasonography; uveal melanoma