title: Hepatopulmonary shunting in patients with primary and secondary liver tumors scheduled for radioembolization.
abstract: OBJECTIVE
  In patients undergoing transarterial radioembolization (RE) of malignant liver tumors, hepatopulmonary shunts (HPS) can lead to nontarget irradiation of the lungs. This study aims at analyzing the HPS fraction in relation to liver volume, tumor volume, tumor-to-liver volume ratio, tumor vascularity, type of tumor, and portal vein occlusion.
  
  
  METHODS
  In the presented retrospective study the percentage HPS fraction was calculated from SPECT/CT after infusion of Tc-99m macroaggregated albumin (Tc-99m MAA) into the proper hepatic artery of 233 patients evaluated for RE.
  
  
  RESULTS
  HPS fractions correlate very weakly with liver volume (r=0.303), tumor volume (r=0.345), and tumor-to-liver volume ratio (r=0.340). Tumors with strong contrast enhancement (HPSmedian(range)=11.7%(46.3%); n=73) have significantly larger shunt fractions than tumors with little enhancement (HPS=8.3%(16.4%); n=61; p<0.001). Colorectal cancer metastases (HPS=10.6%(28.6%); n=68) and hepatocellular cancers (HPS=11.7%(39.4%); n=63) have significantly larger HPS fractions than metastases from breast cancer (HPS=7.4%(16.7%); n=40; p=0.012 and p=0.001). Patients with compression (HPS=13.9%(43.7%); n=33) or tumor thrombosis (HPS=15.8% (31.2%); n=33) of a major portal vein branch have significantly higher degrees of shunting than patients with normal portal vein perfusion (HPS=8.1% (47.0%); n=167; both p<0.001). The shunt fraction is largest in patients with HCC and thrombosis or occlusion of a major portal vein branch (HPS=16.6% (31.0%); n=32).
  
  
  CONCLUSIONS
  The degree of hepatopulmonary shunting depends on the type of liver tumor, tumor vascularity, and portal vein perfusion. There is little to no correlation of HPS with liver volume, tumor volume, or tumor-to-liver volume ratio.
authors.affiliation: Department of Radiology and Nuclear Medicine, Otto-von-Guericke University, Leipziger Strasse 44, 39120 Magdeburg, Germany. Electronic address: maciej.powerski@med.ovgu.de.
authors.forename: Maciej Janusz
authors.initials: MJ
authors.lastname: Powerski
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: christoph.erxleben@charite.de.
authors.forename: Christoph
authors.initials: C
authors.lastname: Erxleben
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: Christian.Scheurig@charite.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Scheurig-Münkler
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: dominik.geisel@charite.de.
authors.forename: Dominik
authors.initials: D
authors.lastname: Geisel
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: uwe.heimann@charite.de.
authors.forename: Uwe
authors.initials: U
authors.lastname: Heimann
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: bernd.hamm@charite.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Hamm
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: bernhard.gebauer@charite.de.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Gebauer
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000473:pathology* / Q000532:radiotherapy; D003287:Contrast Media; D004621:Embolization, Therapeutic / Q000379:methods; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000532:radiotherapy / Q000556:secondary; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011169:Portal Vein / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon; D047368:Tumor Burden; D020246:Venous Thrombosis / Q000000981:diagnostic imaging*; D015021:Yttrium Radioisotopes / Q000627:therapeutic use
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals; D015021:Yttrium Radioisotopes
keywords: Hepatopulmonary shunt; Liver tumor; Radioembolization