Use of C-Arm Cone Beam CT During Hepatic Radioembolization: Protocol Optimization for Extrahepatic Shunting and Parenchymal Enhancement

Cardiovasc Intervent Radiol. 2016 Jan;39(1):64-73. doi: 10.1007/s00270-015-1146-8. Epub 2015 Jun 12.

Abstract

Purpose: To optimize a C-arm computed tomography (CT) protocol for radioembolization (RE), specifically for extrahepatic shunting and parenchymal enhancement.

Materials and methods: A prospective development study was performed per IDEAL recommendations. A literature-based protocol was applied in patients with unresectable and chemorefractory liver malignancies undergoing an angiography before radioembolization. Contrast and scan settings were adjusted stepwise and repeatedly reviewed in a consensus meeting. Afterwards, two independent raters analyzed all scans. A third rater evaluated the SPECT/CT scans as a reference standard for extrahepatic shunting and lack of target segment perfusion.

Results: Fifty scans were obtained in 29 procedures. The first protocol, using a 6 s delay and 10 s scan, showed insufficient parenchymal enhancement. In the second protocol, the delay was determined by timing parenchymal enhancement on DSA power injection (median 8 s, range 4-10 s): enhancement improved, but breathing artifacts increased (from 0 to 27 %). Since the third protocol with a 5 s scan decremented subjective image quality, the second protocol was deemed optimal. Median CNR (range) was 1.7 (0.6-3.2), 2.2 (-1.4-4.0), and 2.1 (-0.3-3.0) for protocol 1, 2, and 3 (p = 0.80). Delineation of perfused segments was possible in 57, 73, and 44 % of scans (p = 0.13). In all C-arm CTs combined, the negative predictive value was 95 % for extrahepatic shunting and 83 % for lack of target segment perfusion.

Conclusion: An optimized C-arm CT protocol was developed that can be used to detect extrahepatic shunts and non-perfusion of target segments during RE.

Keywords: C-arm CT; Cone beam CT; IDEAL; Protocol optimization; Radioembolization.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Collateral Circulation
  • Cone-Beam Computed Tomography / methods*
  • Contrast Media
  • Female
  • Humans
  • Liver / blood supply
  • Liver / diagnostic imaging
  • Liver Circulation
  • Liver Neoplasms / blood supply*
  • Liver Neoplasms / radiotherapy*
  • Male
  • Middle Aged
  • Prospective Studies
  • Radiographic Image Enhancement
  • Radiopharmaceuticals / administration & dosage*
  • Regional Blood Flow
  • Technetium Tc 99m Aggregated Albumin / administration & dosage
  • Triiodobenzoic Acids

Substances

  • Contrast Media
  • Radiopharmaceuticals
  • Technetium Tc 99m Aggregated Albumin
  • Triiodobenzoic Acids
  • iodixanol