Author: Maya Ataya, Clint Bahler, Ramotallah Dami Jubril, Michael Koch, Oluwaseyi Oderinde, Mark Tann 👨🔬
Affiliation: Purdue University, epartment of Urology, Indiana University School of Medicine, Department of Urology, Indiana University School of Medicine, Department of Radiology and Imaging Sciences, Indiana University School of Medicine 🌍
Purpose:
To investigate racial differences in the detection of biochemical recurrence (BCR) using 68Ga-PSMA-11 PET/CT, known for its improved sensitivity and specificity in patients after radical prostatectomy (RP).
Methods:
This retrospective study analyzed data from 79 patients, 65 White American (WAM) and 14 Black and African American men (BAAM) patients who underwent 68Ga-PSMA-11 PET/CT for BCR detection between June 2017 and November 2021 at Indiana University Hospital, Indiana. The data included clinical information and images from 68Ga-PSMA-11 PET/CT scans. The 68Ga PSMA PET/CT image findings were correlated with clinicopathological data prior to relapse and clinical data at the time of recurrence and compared between the two racial groups.
Results:
Overall, 68Ga-PSMA-11-positive lesions were detected in 48/79 (61%) patients, with a significant difference in median PSA at scan for PET-positive (0.79, IQR=0.37-1.90) and PET-negative (0.40, IQR=0.29-0.68) (p= 0.04) patients. Detection rates varied by PSA level at scan: 46% for PSA of 0.2 to <0.5 ng/ml, 71% for 0.5 to <1, 83% for 1 to <2, 64% for 2 <5, and 80% for >5. Biopsy ISUP grade was an independent predictor of 68Ga-PSMA-11 PET/CT positivity (OR= 1.433, CI= 1.018-2.017, p=0.04). Receiver operating characteristic analysis identified a PSA at scan cutoff value of 0.6 ng/ml with 65% sensitivity and 68% specificity. Detection rates between racial cohorts were similar (BAAM: 6/14; WAM: 42/65, p= 0.13). BAAM had significantly higher PSA density (p<0.001) and PSA level prior treatment (p= 0.02) compared to WAM. Other parameters, including PSA level at scan, ISUP grade, and frequency of metastatic involvement, were comparable between the groups.
Conclusion:
68Ga-PSMA-11 PET/CT identified BCR in 61% of patients with biopsy ISUP grades, predicting recurrence detection. Detection rates were comparable between BAAM and WAM, suggesting similar tumor burden. These findings offer valuable insight that can inform future studies with large, racially balanced cohorts.