title: Usefulness of Bremsstrahlung Images after Intra-arterial Y-90 Resin Microphere Radioembolization for Hepatic Tumors.
abstract: OBJECTIVE
  Y-90 resin microsphere radioembolization is used to treat inoperable hepatic tumors. After injection of Y-90 resin microsphere, the only method to visualize the distribution of Y-90 is the scintigraphic imaging of bremsstrahlung radiation. The purpose of this study was to evaluate the characteristics and usefulness of bremsstrahlung imaging in Y-90 resin microsphere treatment.
  
  
  METHODS
  Twenty patients (22 administrations) underwent intra-arterial Y-90 resin microsphere treatment. For pre-treatment planning, images of Tc-99m albumin macroaggregate (MAA) arterial injection and hepatic contrast angiography were obtained. Post-treatment bremsstrahlung images were taken and compared with pre-treatment images. The extrahepatic activity was evaluated on bremsstrahlung images. To correlate the size and vascularity of the tumors with tumor visualization on bremsstrahlung images, the individual tumors were grouped according to visualization on each image and compared with one another by size and tumor-to-normal ratio.
  
  
  RESULTS
  All post-therapeutic bremsstrahlung images showed similar contours of the liver with pre-treatment angiography. No extrahepatic activity was seen in all cases. The visualized tumors on bremsstrahlung images were significantly larger than the non-visualized tumors. Tumor-to-normal ratios of the visualized tumors on bremsstrahlung images were significantly higher than those of the non-visualized tumors.
  
  
  CONCLUSIONS
  Bremsstrahlung images after intra-arterial Y-90 resin microsphere treatment are useful in evaluating the intrahepatic distribution of radioisotope and detecting possible extrahepatic activity.
authors.affiliation: Department of Nuclear Medicine, College of Medicine, Korea University Anam Hospital, Seoul, Republic of Korea.
authors.forename: Young Chul
authors.initials: YC
authors.lastname: Kim
authors.affiliation: Department of Radiology, College of Medicine, Korea University Anam Hospital, Seoul, Republic of Korea.
authors.forename: Yun Hwan
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, College of Medicine, Korea University Anam Hospital, Seoul, Republic of Korea.
authors.forename: Soon Ho
authors.initials: SH
authors.lastname: Um
authors.affiliation: Department of Internal Medicine, College of Medicine, Korea University Anam Hospital, Seoul, Republic of Korea.
authors.forename: Yeon Seok
authors.initials: YS
authors.lastname: Seo
authors.affiliation: Department of Nuclear Medicine, College of Medicine, Korea University Anam Hospital, Seoul, Republic of Korea.
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Park
authors.affiliation: Department of Nuclear Medicine, College of Medicine, Korea University Anam Hospital, Seoul, Republic of Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Oh
authors.affiliation: Department of Radiology, College of Medicine, Hallym University Hangang Sacred Heart Hospital, Seoul, Republic of Korea.
authors.forename: You Mie
authors.initials: YM
authors.lastname: Han
authors.affiliation: Department of Nuclear Medicine, College of Medicine, Korea University Anam Hospital, Seoul, Republic of Korea ; Department of Nuclear Medicine, Korea University Anam Hospital, 126-1 Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-705 South Korea.
authors.forename: Jae-Gol
authors.initials: JG
authors.lastname: Choe
keywords: Bremsstrahlung; Hepatocellular carcinoma; Liver malignancy; Radioembolization; Y-90; microsphere