Standardized uptake values (SUVs) are a quantitative measure of fluorodeoxyglucose (FDG) uptake in tissue, but they have many limitations and variables that must be accounted for. SUVs are influenced by factors like patient size, measurement time, plasma glucose levels, and scanner specifications. While SUVs provide a quantitative evaluation of tumor metabolism and can help distinguish malignant from benign lesions, they should be used cautiously and considered alongside a subjective analysis. SUVs may be helpful but are not definitive, and are only comparable when measured using the same scanner and protocols within an institution.

1. SUV’s - A Brief Overview of Silly Useless Values.
Todd Charge
Senior Technologist
Nuclear Medicine and PET Centre
Hunter Health Imaging Service
Hunter Health Imaging Service

2. 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

3. 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

4. Standardised Uptake Value
Data courtesy Mount Vernon Hospital
Hunter Health Imaging Service

5. Standardised Uptake Value
Pre Treatment Post Treatment
SUV = 18 SUV = 4
Hunter Health Imaging Service

6. Standardised Uptake Value
C /(T )
SUV =
dose/bodyweight
 Where C/(T) = FDG concentration in tissue
at time T
Hunter Health Imaging Service

7. 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

8. 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

9. 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

10. 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

11. 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

12. Summary
 Overall, recognise SUV’s for what they are:
A helpful clue, but not the final answer.
Hunter Health Imaging Service

13. 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