title: Contrast-enhanced ultrasound monitoring of perfusion changes in hepatic neuroendocrine metastases after systemic versus selective arterial 177Lu/90Y-DOTATOC and 213Bi-DOTATOC radiopeptide therapy.
abstract: OBJECTIVE
  Radiopeptide therapy with beta emitter labeled (177)Lu/(90)Y- DOTA(0)-Phe(1)-Tyr(3)-octreotide (DOTATOC) and more recently also alpha emitting (213)Bi-DOTATOC are promising new treatments for neuroendocrine tumors. No early predictors for treatment response have been recognized and tumor-shrinkage after radiation therapy appears slowly. In some solid tumors a decline in tumor perfusion was found predictive of final treatment response but the gold standard multiphase computed tomography (CT) has a high radiation burden. Therefore we evaluated the ability of contrast-enhanced ultrasound (CEUS) to evaluate tumor perfusion as a response criteria.
  
  
  METHODS
  14 patients with hepatic neuroendocrine tumor (NET) metastases were enrolled in the retrospective study. Eleven patients were treated with beta-emitting (177)Lu/(90)Y-DOTATOC, either intravenous (i.v.) (n = 5) or intra-arterial (i.a.) (n = 6) and three patients received alpha-emitting (213)Bi-DOTATOC (i.a.). CEUS and contrast-enhanced CT (CE-CT) were performed before and 3 months after treatment.
  
  
  RESULTS
  CE-CT and CEUS presented comparable results in the baseline study and in the assessment of perfusion changes due to the different treatment regimes. A therapy related decrease in tumor perfusion is an early predictor of longterm morphologic response.
  
  
  CONCLUSIONS
  CEUS is available and radiation free technique which showed comparable results for perfusion and diameter of liver metastases compared to CE-CT. Intensity reduction in an arterial phase CEUS can be seen as a positive sign indicating long term tumor response to treatment. Therefore CEUS may be considered as an imaging modality for monitoring early treatment after focal alpha and beta targeted therapy.
authors.affiliation: Department of Nuclear Medicine, University Hospital Heidelberg, INF 400, 69120 Heidelberg, Germany. frederik.giesel@med.uni-heidelberg.de
authors.forename: F L
authors.initials: FL
authors.lastname: Giesel
authors.forename: S
authors.initials: S
authors.lastname: Wulfert
authors.forename: C M
authors.initials: CM
authors.lastname: Zechmann
authors.forename: U
authors.initials: U
authors.lastname: Haberkorn
authors.forename: C
authors.initials: C
authors.lastname: Kratochwil
authors.forename: P
authors.initials: P
authors.lastname: Flechsig
authors.forename: T
authors.initials: T
authors.lastname: Kuder
authors.forename: L H
authors.initials: LH
authors.lastname: Schwartz
authors.forename: F
authors.initials: F
authors.lastname: Bruchertseifer
mesh_terms: D001729:Bismuth; D003287:Contrast Media; D007261:Infusions, Intra-Arterial; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy*; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy*; D015282:Octreotide / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000601:surgery; D055420:Perfusion Imaging; D049268:Positron-Emission Tomography / Q000379:methods; D011868:Radioisotopes / Q000627:therapeutic use; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D014463:Ultrasonography
chemical_list: C504257:177Lu-octreotide, DOTA(0)-Tyr(3)-; D003287:Contrast Media; D011868:Radioisotopes; C496730:90Y-octreotide, DOTA-Tyr(3)-; D015282:Octreotide; D001729:Bismuth