Evaluating the Correlation Between Serum PSA Values and Gleason Score of the Prostate Carcinoma with Ga68-PSMA Uptake in the Prostate Tumor in Primary Staging

Abstract

Introduction : Ga68-PSMA PET/CT has a crucial role in staging, evaluation of treatment, and diagnosis of local recurrence of prostate tumors and has recently been suggested by some guidelines as a staging method for intermediate and high-risk patients. This study aimed to evaluate the correlation between serum PSA levels and Gleason score of the prostate tumor, with the findings of Ga68-PSMA PET/CT scan in primary staging. Methods In the present cross-sectional study, all patients with prostate cancer who were referred to the nuclear medicine ward of Razavi Hospital, Mashhad, Iran, for Ga68-PSMA PET/CT whole body scan from 21 March 2021 until 21 March 2022 were enrolled. The results of each of the three stages of the scan (early, whole-body, and late) were recorded. The standardized uptake value of Ga68-PSMA in the primary tumor and its association with serum PSA, tumor Gleason score, and presence of tumor metastasis were evaluated and analyzed. In all statistical analyses, p < 0.05 was considered statistically significant. Findings : In total, 49 male patients with a median age of 65 years (Interquartile range: 59–69) were studied. 43.9% of the patients were in the high-risk group (Gleason score 9–10). The median serum PSA level was 17 ng/mL (Interquartile range: 8.02–42.10). PSA levels correlated with the SUVmax of the tumor in the whole-body stage of the scan (p < 0.05, r = + 0.392) but not early or late stages (p > 0.05). Gleason scores were positively correlated with tumor SUVmax in all three scan stages (p < 0.05). Conclusion Our results indicated that the Gleason score significantly correlated with the SUVmax of the prostate tumor in all three stages of the scan; however, serum PSA levels correlated with the tumor SUVmax in the whole-body stage of the scan but not in the early and late stages. In the whole-body stage, higher SUVmax was significantly associated with higher Gleason scores (9–10 vs. 7–8), bladder wall and seminal vesicle invasion, and lymph node metastasis (p < 0.05 in all cases), too.