Background: Conflicting results have been revealed on the relationship between PSMA uptake values (SUVs) on prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) and prostate cancer (PCa) aggressiveness. This study is to validate the relationship between SUVs with PCa aggressiveness and its role in evaluation of clinically significant PCa (csPCa) and risk stratification.
Methods: We retrospectively enrolled 51 patients who underwent [68Ga]-PSMA PET/CT (PET/CT) before radical prostatectomy (RP). PET/CT results were corrected with whole mount histology. The relationship between SUVs and aggressiveness related indictors including Gleason score, T stage, initial PSA and tumor size were analyzed. The cutoff value for detection of overall PCa, csPCa and intermediate/high-risk PCa were calculated by receiver operating characteristics (ROC) analysis.
Results: Both SUV<inf>max</inf> and SUV<inf>mean</inf> positively correlated with Gleason score (SUV<inf>max</inf> Spearman r=0.546 P<0.01, SUV<inf>mean</inf> Spearman r=0.359 P<0.01), PSA level (SUV<inf>max</inf> Spearman r=0.568 P<0.01, SUV<inf>mean</inf> Spearman r=0.529 P<0.01) and tumor volume SUV<inf>max</inf> Spearman r=0.635 P<0.01, SUV<inf>mean</inf> Spearman r=0.590 P<0.01). Tumors with T3 stage had significant higher SUV uptake than T2 (SUV<inf>max</inf> 17.49±10.50 vs 9.90±8.7, P<0.01 and SUV<inf>mean</inf> 17.49±10.50 vs 9.90±8.7, P<0.01). ROC analysis showed cutoff of SUV<inf>max</inf> (3.8) and SUV<inf>mean</inf> (2.8) for overall PCa detection. ROC analysis showed that csPCa and intermediate/high risk PCa had the same cutoff on both SUV<inf>max</inf> (8.4) and SUV<inf>mean</inf> (6.8).
Conclusions: PSMA uptake on PSMA PET/CT positively correlated with Gleason score, T stage, initial PSA and tumor volume. Both SUV<inf>max</inf> and SUV<inf>mean</inf> can be applied as parameters for csPCa detection and risk classification.