SUV- standardised uptake values in pet scanning

SUV- standardised uptake values in pet scanning

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  SUV’s - ABrief Overview of Silly Useless Values. Todd Charge Senior Technologist Nuclear Medicine and PET Centre Hunter Health Imaging Service Hunter Health Imaging Service
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  Standardised Uptake Values Quantification has always held a pervasive allure for Nuclear Medicine. There is a sense that anything that can be quantified should be. J.W. Keyes Jr. PET Centre North Carolina USA Journal Nuclear Medicine 1995; 36:1836-1839 Hunter Health Imaging Service
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  What are SUV’s?  A measure of FDG uptake as a function of time  Quantitative evaluation of tumour metabolism  Often used as a measure of malignancy vs. benignancy of lesion Hunter Health Imaging Service
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  Standardised Uptake Value Datacourtesy Mount Vernon Hospital Hunter Health Imaging Service
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  Standardised Uptake Value Pre Treatment Post Treatment SUV = 18 SUV = 4 Hunter Health Imaging Service
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  Standardised Uptake Value C /(T ) SUV = dose/bodyweight  Where C/(T) = FDG concentration in tissue at time T Hunter Health Imaging Service
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  Standardised Uptake Value  Tracer concentration is usually determined from the image pixel that shows the highest lesion activity  Average concentration was once used but is not routinely in use now Hunter Health Imaging Service
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  Assumptions of SUV’s  Negligible free FDG in tissue at time of PET scan  Equilibrium reached between plasma and free FDG in tissue  All tissues are affected in the same way by glucose levels Hunter Health Imaging Service
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  Variables Influencing SUV’s  Large number of variables which need to be taken into account.  Patient size  Measurement times  Plasma Glucose  ROI  Partial Volume Effect  Camera specifications Hunter Health Imaging Service
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  Summary  Use of Lean Body Mass instead of true weight  Take plasma glucose levels into account, tumour type & possible treatment effects  Standardise uptake time, attenuation correction, scatter correction and filtering  Consider ROI placement and use of max pixel Hunter Health Imaging Service
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  Summary  Only use SUV within institution and even camera specific  Be careful when using SUV threshold to distinguish tumour from normal tissue  Consider SUV in conjunction with a subjective analysis of a lesion. Hunter Health Imaging Service
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  Summary  Overall, recognise SUV’s for what they are: A helpful clue, but not the final answer. Hunter Health Imaging Service
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  References  DiChiro G, Brooks RA. “PET quantitation: Blessing and Curse.” J Nucl Med 1988:29;1603-1604  S Meikle “Quantitative Methods and Factors Affecting SUV Calculation” ANZSNM PET Workshop 2003  JW Keyes “SUV: Standard Uptake or Silly Useless Value?” J Nucl Med 36:1836-1839, 1995 Hunter Health Imaging Service