PET/CT images quantification for diagnostics and radiotherapy applications

ABSTRACT

Background: In our Institute PET/CT images are used for detecting, staging and monitoring various malignant tumours. Standard Uptake Value (SUV) is now common place in our clinical PET/CT oncology. Moreover, PET images are used for target volume definition in radiotherapy applications. Even if PET represents a powerful diagnostics tool, the quantitative data extracted from PET are affected by the limited resolution of the system. The aims of this work is to analysed by a phantom study the accuracy of the data quantified by our tomograph and the validation of the segmentation method used for radiotherapy applications.

Methods: The phantom study was performed on a PET/CT system using the IEC Phantom with spheres filled with different sphere/background activity ratios (RS/B). Sphere volumes were determined using an adaptive thresholding method. SUV assessment was evaluated measuring the SUV values in each sphere and the percentage error respect to the true value. Hot Contrast Recovery Coefficients (HCRC) were also measured.

Results: A linear relationship between thresholds and volumes was observed for volumes up to 10 mL. Between 10 mL and 5.5 mL thresholds decrease reaching a minimum at 1.1 mL. For volumes S/Band smoothing filter. SUV is quantified for volumes up to 2.5 mL with an underestimation of 10%, for smaller dimensions SUV values are underestimated up to 80%. Hot Contrast Recovery Coefficients range from 87% to 16%.

Conclusions: For objects with very small volume (

Keywords: Positron emission tomography; Quantitative approaches; Segmentation; SUV

Citation: Ferrando O, Foppiano F, Scolaro T, Gaeta C, Ciarmiello A. PET/CT images quantification for Diagnostics and Radiotherapy applications. Journal of Diagnostic Imaging in Therapy. 2015; 2(1): 18-29.

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DOI: http://dx.doi.org/10.17229/jdit.2015-0216-013

Copyright: © 2015 Ferrando O, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are cited.

Received: 06 February 2015 | Revised: 15 February 2015 | Accepted: 16 February 2015  

Published Online 16 February 2015 http://www.openmedscience.com

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