title: Monitoring of liver metastases after stereotactic radiotherapy using low-MI contrast-enhanced ultrasound--initial results.
abstract: The purpose of this study was to monitor liver metastases after radiotherapy using contrast-enhanced ultrasound (CEUS). In 15 patients, follow-up examinations after stereotactic, single-dose radiotherapy were performed using CEUS (low mechanical index (MI), 2.4-ml SonoVue) and computed tomography (CT). Besides tumor size, the enhancement of the liver and the metastases was assessed at the arterial, portal venous, and delayed phases. The sizes of the tumor and of a perifocal liver reaction after radiotherapy measured with CEUS significantly correlated with those measured at CT (r=0.93, p<0.001). CEUS found a significant reduction of the arterial vascularization in treated tumors (p<0.05). In the arterial phase, the perifocal liver tissue was hypervascularized compared to the treated tumor (p<0.001); in the late phase, it was less enhanced than the liver (p<0.001) and more than the tumor (p<0.01). The perifocal liver reaction was also seen in CT, but with a variable enhancement at the arterial (50% hyperdense compared to normal liver tissue), venous, or delayed phase (each with 70% hyperdense reactions). CEUS allows for the assessment of tumor and liver perfusion, in addition to morphological tumor examination, which was comparable with CT. Thus, changes of tumor perfusion, which may indicate tumor response, as well as the perifocal liver reaction after radiotherapy, which must be differentiated from perifocal tumor growth, can be sensitively visualized using CEUS.
authors.affiliation: German Cancer Research Center--Radiology, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany. m.krix@dkfz.de
authors.forename: M
authors.initials: M
authors.lastname: Krix
authors.forename: C
authors.initials: C
authors.lastname: Plathow
authors.forename: M
authors.initials: M
authors.lastname: Essig
authors.forename: K
authors.initials: K
authors.lastname: Herfarth
authors.forename: J
authors.initials: J
authors.lastname: Debus
authors.forename: H-U
authors.initials: HU
authors.lastname: Kauczor
authors.forename: S
authors.initials: S
authors.lastname: Delorme
mesh_terms: D003287:Contrast Media; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000532:radiotherapy / Q000556:secondary*; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D014463:Ultrasonography
chemical_list: D003287:Contrast Media
references.citation: Circulation. 1998 Feb 10;97(5):473-83
references.pmid: 9490243
references.citation: Cancer. 2004 Mar 15;100(6):1246-56
references.pmid: 15022293
references.citation: Ann Surg. 2003 Feb;237(2):171-9
references.pmid: 12560774
references.citation: Acta Radiol. 2001 Sep;42(5):526-31
references.pmid: 11552892
references.citation: J Comput Assist Tomogr. 1999 Sep-Oct;23 (5):655-63
references.pmid: 10524841
references.citation: Eur Radiol. 1999;9(4):675-84
references.pmid: 10354884
references.citation: Eur Radiol. 2004 Jun;14 (6):1092-9
references.pmid: 15007620
references.citation: Eur Radiol. 2003 Mar;13(3):475-83
references.pmid: 12594549
references.citation: Eur Radiol. 2004 Jun;14 (6):1082-91
references.pmid: 15108017
references.citation: Cell Tissue Res. 2003 Apr;312(1):49-54
references.pmid: 12712317
references.citation: Int J Radiat Oncol Biol Phys. 2003 Oct 1;57(2):444-51
references.pmid: 12957256
references.citation: Invest Radiol. 2000 Jan;35(1):58-71
references.pmid: 10639037
references.citation: Strahlenther Onkol. 2000 Dec;176(12):567-72
references.pmid: 11140151
references.citation: Eur Radiol. 2002 Jan;12 (1):151-65
references.pmid: 11868093
references.citation: Strahlenther Onkol. 2001 Dec;177(12):645-55
references.pmid: 11789403
references.citation: J Clin Oncol. 2001 Jan 1;19(1):164-70
references.pmid: 11134209
references.citation: AJR Am J Roentgenol. 1995 Jul;165(1):79-84
references.pmid: 7785638
references.citation: J Magn Reson Imaging. 2000 Dec;12(6):1027-33
references.pmid: 11105046
references.citation: Cancer. 1981 Jan 1;47(1):207-14
references.pmid: 7459811
references.citation: Eur Radiol. 2004 Jun;14 (6):1100-8
references.pmid: 14676975
references.citation: Lancet. 2000 Mar 4;355(9206):807-8
references.pmid: 10711932
references.citation: Invest Radiol. 2004 Apr;39(4):216-22
references.pmid: 15021325
references.citation: Arch Pathol Lab Med. 1980 Nov;104(11):584-8
references.pmid: 6893535
references.citation: J Clin Ultrasound. 2002 Oct;30(8):465-71
references.pmid: 12242734
references.citation: Ultrasound Med Biol. 2004 Jun;30(6):851-4
references.pmid: 15219964
references.citation: Z Gastroenterol. 2004 Jan;42(1):31-8
references.pmid: 14997401
references.citation: Rofo. 2003 Oct;175(10 ):1403-12
references.pmid: 14556110
references.citation: N Engl J Med. 1991 Jan 3;324(1):1-8
references.pmid: 1701519