From the Guidelines
A high Standardized Uptake Value (SUV) on a Positron Emission Tomography (PET) scan typically indicates increased metabolic activity in the tissue being examined, which often suggests the presence of malignancy or active inflammation, as supported by the most recent study 1. This value represents the concentration of the radiotracer (usually fluorodeoxyglucose or FDG) in a specific area compared to what would be expected in normal tissue.
- Cancer cells generally consume more glucose than normal cells due to their rapid growth and altered metabolism, leading to greater uptake of FDG and consequently higher SUV measurements.
- However, it's essential to understand that high SUV values are not exclusively indicative of cancer, as various non-malignant conditions such as infections, inflammation, healing fractures, and even normal physiological processes in organs like the brain, heart, and urinary tract can also demonstrate elevated SUV readings. The interpretation of SUV values must always be considered in the clinical context of the patient, including their medical history, symptoms, and results from other diagnostic tests, as highlighted in 1 and 1. SUV measurements are particularly valuable for monitoring treatment response in cancer patients, where decreasing values often correlate with effective therapy, as noted in 1. Some key points to consider when interpreting SUV values include:
- The clinical context of the patient
- The presence of non-malignant conditions that may cause elevated SUV readings
- The use of SUV measurements in conjunction with other diagnostic tests
- The potential for false-positive or false-negative results, as discussed in 1 and 1.
From the Research
Standardized Uptake Value (SUV) on PET Scan
- A high Standardized Uptake Value (SUV) on a Positron Emission Tomography (PET) scan indicates increased fluoro-deoxyglucose (FDG) uptake by a tumor, which can be associated with aggressive tumor behavior 2.
- Studies have shown that SUVs are correlated with clinicopathological factors such as mitotic counts, Ki67 positive cell percentage, and nuclear grade, reflecting cellular aggressiveness 2.
- A maximum FDG uptake of >10 SUV seems to significantly correlate with an aggressive B-cell lineage in lymphoma patients 3.
Factors Affecting SUV Uptake
- Several factors can affect FDG uptake by a tumor, including image reconstruction, resolution, and region of interest (ROI) definition parameters 4.
- The use of intravenous contrast agent in CT scans for PET attenuation correction can result in a bias in attenuation factors, but this bias has been shown to be clinically insignificant in most cases 5, 6.
- Standardization of acquisition, reconstruction, and ROI methods is preferred for SUV quantification in multi-centre trials to minimize variations in SUV uptake 4.