For men with intermediate-risk prostate cancer, maximum standardized uptake value (SUVmax) on 68Ga-prostate-specific membrane antigen (PSMA)-11 positron emission tomography (PET)/computed tomography (CT) is associated with Gleason pattern 4 (GP4), according to a study published online in The Journal of Urology.
Alan L. Xue, from Monash University in Melbourne, Australia, and colleagues reviewed data for men with International Society of Urological Pathology Grade Group 2 to 3 disease on transperineal template biopsy undergoing 68Ga-PSMA-11 PET/CT to examine its impact on risk stratification. The primary outcome was the presence of a high percentage of GP4 disease per segment at surgery. SUVmax was compared by the presence of GP4, and the association between SUVmax and GP4 was examined.
Two hundred twenty men underwent biopsy, and of these, 135 underwent surgery. The researchers found that in high GP4 groups, SUVmax was higher (5.51 versus 3.31 for >/<50 percent GP4; 4.77 versus 3.13 for >/<20 percent GP4; and 4.54 versus 3.03 for >/<10 percent GP4). SUVmax independently predicted >50 and >20 percent GP4 disease per segment (odds ratios, 1.39 and 1.24, respectively) and predicted pathologic upgrading (odds ratio, 1.22). A threshold of 4.5 on SUVmax predicted >20 percent GP4 with sensitivity, specificity, a positive predictive value, and a negative predictive value of 58, 85, 75, and 72 percent, respectively. A threshold of 5.4 predicted pathologic upgrading with specificity of 91 percent and a negative predictive value of 94 percent.
“SUVmax may add another layer of safety as a quantitative measurement to better risk stratify patients for surveillance or treatment in favorable intermediate-risk prostate cancer,” the authors write.