Gallium 68-labelled prostate-specific membrane antigen positron emission tomography/computed tomography (68Ga PSMA PET/CT) can identify which men with indeterminate PI-RADS 3 lesions on multiparametric magnetic resonance imaging (mpMRI) harbor clinically significant prostate cancer greater than Gleason 3+3 and should undergo prostate biopsy, a new study finds.
A team led by Shuo Hu, PhD, of Xiangya Hospital, Central South University in Changsha, Hunan, China, examined the diagnostic value of 68Ga-PSMA PET/CT among 78 men with PI-RADS 3 lesions on mpMRI. After transrectal ultrasound MRI fusion-guided biopsy, the investigators found that 26 men had clinically significant prostate cancer.
Features associated with clinically significant vs insignificant prostate cancer included a lower ADCT/ADCCLP (0.65 vs 0.71), smaller prostate volume (25.27 vs 42.79 mL), lower free PSA to total PSA ratio (0.11 vs 0.16), higher PSA level (13.45 vs 7.90 ng/mL), higher PSA density (0.40 vs 0.16 ng/mL2), higher SUVmax (9.80 vs 4.40), and higher SUVT/BGp (2.41 vs 1.00). A ROC analysis demonstrated that SUVmax and SUVT/BGp on 68 Ga-PSMA PET/CT outperformed all other features for detection of clinically significant prostate cancer. The diagnostic sensitivity and specificity for clinically significant prostate cancer were 96.2% and 100% and 80.8% and 84.6% using cutoff values of 5.0 for SUVmax and 1.4 for SUVT/BGp, respectively, Dr Hu’s team reported in The Prostate.
According to the investigators, it is reasonable to perform biopsies only in men who have PI-RADS 3 lesions with positive PSMA PET/CT findings.
Yang J, Tang Y, Zhou C, Zhou M, Li J, Hu S. The use of 68Ga-PSMA PET/CT to stratify patients with PI-RADS 3 lesions according to clinically significant prostate cancer risk. Prostate. Published online December 21, 2022. doi:10.1002/pros.24475