Metabolic Tumor Volume Is More Accurate Than SUV Metrics in PSMA-PET/CT Analysis Across Different PET/CT Scanners.
Yang Lu
✦ AI-curated · Sources linked
Case in brief
A 66-year-old man with metastatic prostate cancer had PSMA-avid local recurrence on follow-up PSMA-PET/CT and MRI. Across three PET studies, SUVmax, SUVmean, and total lesion glycolysis (TLG) did not track consistently with concurrent PSA, and the first scan, acquired on a different scanner, had the highest SUV values but the lowest metabolic tumor volume (MTV). MTV increased from 3.6 to 5.9 to 8.4 mL as PSA rose from 0.1 to 0.3 to 0.6 ng/mL. The authors considered MTV more consistent with PSA change and less dependent on scanner differences.
What made this case unusual
SUV metrics and MTV moved in opposing directions: the scan with the highest SUVmax and SUVmean had the lowest MTV, while MTV rose across scans as PSA increased. The first scan was acquired on a different PET/CT scanner.
Diagnostic / clinical pearl
In this case, MTV tracked concurrent PSA more consistently than SUV metrics across serial PSMA-PET/CT studies, including scans acquired on different scanners.