Assessment of acquisition protocols for routine imaging of Y-90 using PET-CTReport as inadecuate




Assessment of acquisition protocols for routine imaging of Y-90 using PET-CT - Download this document for free, or read online. Document in PDF available to download.

EJNMMI Research

, 3:11

First Online: 17 February 2013Received: 12 October 2012Accepted: 08 December 2012DOI: 10.1186-2191-219X-3-11

Cite this article as: Carlier, T., Eugène, T., Bodet-Milin, C. et al. EJNMMI Res 2013 3: 11. doi:10.1186-2191-219X-3-11

Abstract

BackgroundDespite the early theoretical prediction of the 0-0 transition of Zr, Y-PET underwent only recently a growing interest for the development of imaging radioembolization of liver tumors. The aim of this work was to determine the minimum detectable activity MDA of Y by PET imaging and the impact of time-of-flight TOF reconstruction on detectability and quantitative accuracy according to the lesion size.

MethodsThe study was conducted using a Siemens Biograph® mCT with a 22 cm large axial field of view. An IEC torso-shaped phantom containing five coplanar spheres was uniformly filled to achieve sphere-to-background ratios of 40:1. The phantom was imaged nine times in 14 days over 30 min. Sinograms were reconstructed with and without TOF information. A contrast-to-noise ratio CNR index was calculated using the Rose criterion, taking partial volume effects into account. The impact of reconstruction parameters on quantification accuracy, detectability, and spatial localization of the signal was investigated. Finally, six patients with hepatocellular carcinoma and four patients included in different Y-based radioimmunotherapy protocols were enrolled for the evaluation of the imaging parameters in a clinical situation.

ResultsThe highest CNR was achieved with one iteration for both TOF and non-TOF reconstructions. The MDA, however, was found to be lower with TOF than with non-TOF reconstruction. There was no gain by adding TOF information in terms of CNR for concentrations higher than 2 to 3 MBq mL, except for infra-centimetric lesions. Recovered activity was highly underestimated when a single iteration or non-TOF reconstruction was used 10% to 150% less depending on the lesion size. The MDA was estimated at 1 MBq mL for a TOF reconstruction and infra-centimetric lesions. Images from patients treated with microspheres were clinically relevant, unlike those of patients who received systemic injections of Y.

ConclusionsOnly one iteration and TOF were necessary to achieve an MDA around 1 MBq mL and the most accurate localization of lesions. For precise quantification, at least three iterations gave the best performance, using TOF reconstruction and keeping an MDA of roughly 1 MBq mL. One and three iterations were mandatory to prevent false positive results for quantitative analysis of clinical data.

Trial registrationhttp:-IDRCB2011-A00043-38P101103

Keywords90-Y PET Quantification Detectability Radioembolization Electronic supplementary materialThe online version of this article doi:10.1186-2191-219X-3-11 contains supplementary material, which is available to authorized users.

Download fulltext PDF



Author: Thomas Carlier - Thomas Eugène - Caroline Bodet-Milin - Etienne Garin - Catherine Ansquer - Caroline Rousseau - Ludovic Fe

Source: https://link.springer.com/







Related documents