title: Perfusion patterns of metastatic gastrointestinal stromal tumor lesions under specific molecular therapy.
abstract: OBJECTIVE
  The aim of this pilot study was the evaluation of CT perfusion patterns in metastatic GIST lesions under specific molecular therapy with sunitinib or imatinib both in responders and non-responders.
  
  
  METHODS
  24 patients with metastatic GIST under tyrosine kinase inhibition were retrospectively evaluated. A total of 46 perfusion and venous phase CT scans were acquired. Volume of distribution, blood flow, blood volume, permeability and hepatic perfusion index measurements of metastatic lesions were carried out. Lesions were classified as "good response" or "poor response" to therapy, and perfusion parameters were compared for these two types of lesions.
  
  
  RESULTS
  24 patients were evaluated. In the extrahepatic abdominal lesions (N = 15), good responders showed significant lower perfusion values than poor responders (volume of distribution: 3.3 ± 2.0 vs. 13.0 ± 1.8 ml/100ml, p = 0.001). The same tendency was observed in intrahepatic lesions (N = 31) (liver volume of distribution: 2.1 ± 0.3 vs. 7.1 ± 1.3 ml/100ml, p = 0.003); (hepatic perfusion index: 24.3 ± 7.9 vs. 76.1 ± 1.5%, p = 0.0001).
  
  
  CONCLUSIONS
  Our data indicate that there are characteristic perfusion patterns of metastatic GIST lesions showing a good or poor response to molecular pharmacotherapy. Perfusion should be further evaluated in cross-sectional imaging studies as a possible biomarker for treatment response in targeted therapies of GIST.
authors.affiliation: Department of Internal Medicine III, University Hospitals-Großhadern, Ludwig Maximilians University Munich, Marchioninistr 15, 81377 Munich, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Schlemmer
authors.forename: Steven P
authors.initials: SP
authors.lastname: Sourbron
authors.forename: Nicole
authors.initials: N
authors.lastname: Schinwald
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
authors.forename: Christoph R
authors.initials: CR
authors.lastname: Becker
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Frank
authors.initials: F
authors.lastname: Berger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001549:Benzamides; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000556:secondary; D006801:Humans; D000068877:Imatinib Mesylate; D007211:Indoles / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D058990:Molecular Targeted Therapy / Q000379:methods; D055420:Perfusion Imaging / Q000379:methods*; D010865:Pilot Projects; D010879:Piperazines / Q000627:therapeutic use*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011743:Pyrimidines / Q000627:therapeutic use*; D011758:Pyrroles / Q000627:therapeutic use*; D000077210:Sunitinib; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D007211:Indoles; D010879:Piperazines; D011743:Pyrimidines; D011758:Pyrroles; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases; D000077210:Sunitinib