Ga-labeled prostate specific membrane antigen HBED-CC PET/MRI for staging and evaluating the clinicopathological characteristics in newly diagnosed prostate cancer.

OBJECTIVE

The purpose of this study was to investigate the role of Ga-labeled prostate specific membrane antigen HBED-CC (Ga-PSMA-11) PET/MRI in primary staging and to evaluate the relationship between PSMA-derived parameters and clinicopathological characteristics in newly diagnosed prostate cancer (PCa).

MATERIALS AND METHODS

This study reports the findings from 72 patients newly diagnosed with primary PCa, all of whom underwent Ga-PSMA-11 PET/MRI scans. Calculated the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of Ga-PSMA-11 PET/MRI for T, N, M staging, respectively. The maximum standardized uptake value (SUVmax), PSMA-tumor volume (PSMA-TVp), and total lesion-PSMA (TL-PSMAp) of primary lesion, PSMA-TV of total lesions (PSMA-TVt), and TL-PSMA of total lesions (TL-PSMAt) were measured, and Spearman correlation analysis was performed to assess their correlation with baseline prostate-specific antigen (PSA). Non-parametric Mann-Whitney U test was conducted to assess the difference of PSMA-derived parameters among clinicopathological characteristics of PCa. Receiver operating characteristic (ROC) curve was used to evaluate the performance of PSMA-derived parameters in diagnosing the clinicopathological characteristics of PCa.

RESULTS

The overall accuracy of Ga-PSMA-11 PET/MRI in detecting T staging of PCa was 80.7%. Diagnostic accuracy for T2a, T2b, T2c, T3a, and T3b were 94.2%, 92.3%, 90.4%, 90.4%, and 94.2%, respectively. Diagnostic accuracy for N and M staging were 96.1% and 97.2% based on patients-level, respectively. There were significant correlation between the SUVmax, PSMA-TVp, TL-PSMAp, PSMA-TVt, TL-PSMAt and baseline PSA values. Significant differences were observed in SUVmax, PSMA-TVp, TL-PSMAp, PSMA-TVt, and TL-PSMAt between T3 and T2 staging. Statistical differences were observed in SUVmax, TL-PSMAp, PSMA-TVt, and TL-PSMAt between Gleason Score (GS) > 7 and GS ≤ 7, as well as positive and negative regional lymph node metastasis. TL-PSMAt show the highest value in assessing clinicopathological characteristics.

CONCLUSIONS

Ga-PSMA-11 PET/MRI can provide accurate TNM staging for PCa, particularly in local staging. TL-PSMAt accurately evaluate overall tumor burden and aids in diagnosing clinicopathological characteristics in mid-to-late-stage patients, outperforming SUVmax.