title: Evaluation of intrahepatic perfusion on fusion imaging using a combined CT/SPECT system: influence of anatomic variations on hemodynamic modification before installation of implantable port systems for hepatic arterial infusion chemotherapy.
abstract: BACKGROUND
  In some patients with hepatic tumors, anatomic variations in the hepatic arteries may require hemodynamic modification to render effective hepatic arterial infusion chemotherapy delivered via implantable port systems. We used a combined CT/SPECT system to obtain fused images of the intrahepatic perfusion patterns in patients with such anatomic variations and assessed their effects on the treatment response of hepatic tumors.
  
  
  METHODS
  Using a combined SPECT/CT system, we obtained fused images in 110 patients with malignant liver tumors (n = 75) or liver metastasis from unresectable pancreatic cancer (n = 35). Patients with anatomic hepatic arteries variations underwent hemodynamic modification before the placement of implantable port systems for hepatic arterial infusion chemotherapy. We evaluated their intrahepatic perfusion patterns and the initial treatment response of their liver tumors. The perfusion patterns on the fused images were classified as homogeneous, local hypoperfusion, and/or perfusion defect. Using the WHO criteria of complete response (CR), partial response (PR), no change (NC), and progressive disease (PD), we evaluated the patients' tumor responses after 3 months on multislice helical CT scans. The treatment was regarded as effective in patients who achieved a complete response or partial response.
  
  
  RESULTS
  Anatomic hepatic artery variations were present in 15 of the 110 patients (13.6%); 5 manifested replacement of the left hepatic artery (LHA), 8 of the right hepatic artery (RHA), and 1 each had replacement of the RHA and LHA, and replacement of the LHA plus an accessory RHA. In 13 of these 15 patients (87%), occlusion with metallic coils was successful. On fusion imaging, the perfusion patterns were recorded as homogeneous in 6 patients (43%), as hypoperfusion in 7 (50%), and 1 patient had a perfusion defect (7.1%) in the embolized arterial region. Of the 8 patients with RHA replacement, 4 manifested a homogeneous distribution and 3 hypoperfusion. In 2 of 5 patients with LHA replacement, the distribution was homogeneous. In 1 patient with RHA and LHA replacement, and in 1 patient with LHA replacement and an accessory RHA, we noted hypoperfusion in the RHA territory. All 6 patients with homogeneous distribution were classified as PR or NC on follow-up multidetector CT. Of the 7 patients manifesting hypoperfusion, 3 were classified as PD (43%), 3 as NC (43%), and 1 as PR (14%) on follow-up CT.
  
  
  CONCLUSIONS
  Hemodynamic modification of anatomic hepatic artery variations resulted in hypoperfusion on fusion images. Differences in the intrahepatic perfusion patterns may affect the response to hepatic arterial infusion chemotherapy.
authors.affiliation: Department of Diagnostic Radiology, Kumamoto University Graduate School of Medical and Pharmaceutical Sciences, 1-1-1, Honjo, Kumamoto 860-8556, Japan. osamu-3643ik@do9.enjoy.ne.jp
authors.forename: Osamu
authors.initials: O
authors.lastname: Ikeda
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tamura
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakasone
authors.forename: Shinya
authors.initials: S
authors.lastname: Shiraishi
authors.forename: Kouichi
authors.initials: K
authors.lastname: Kawanaka
authors.forename: Seiji
authors.initials: S
authors.lastname: Tomiguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takamori
authors.forename: Akira
authors.initials: A
authors.lastname: Chikamoto
authors.forename: Keiichirou
authors.initials: K
authors.lastname: Kanemitsu
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D000792:Angiography; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D006528:Carcinoma, Hepatocellular / Q000098:blood supply* / Q000188:drug therapy; D002408:Catheters, Indwelling; D002945:Cisplatin / Q000008:administration & dosage / Q000009:adverse effects; D003841:Deoxycytidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D004621:Embolization, Therapeutic; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects; D006499:Hepatic Artery / Q000002:abnormalities* / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007261:Infusions, Intra-Arterial; D008099:Liver / Q000098:blood supply*; D008113:Liver Neoplasms / Q000098:blood supply* / Q000188:drug therapy / Q000556:secondary; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000098:blood supply* / Q000188:drug therapy; D012039:Regional Blood Flow / Q000502:physiology; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D000093542:Gemcitabine
chemical_list: D003841:Deoxycytidine; D002945:Cisplatin; D005472:Fluorouracil; D000093542:Gemcitabine