Diagnostic Performance of ⁶⁸Ga-PSMA-11 PET/CT Versus Multiparametric MRI for Detection of Intraprostatic...

Area of Science:

• Nuclear Medicine
• Radiology
• Oncology

Background:

• European guidelines suggest Gallium-68 PSMA PET/CT and multiparametric MRI (mpMRI) for men with prostate cancer experiencing biochemical failure post-radiotherapy.
• The diagnostic accuracy of Gallium-68 PSMA PET/CT for detecting intraprostatic recurrences, with or without mpMRI, requires further clarification.

Purpose of the Study:

• To evaluate the accuracy of Gallium-68 PSMA PET/CT in detecting intraprostatic prostate cancer recurrence.
• To compare the diagnostic performance of PET/CT alone versus mpMRI alone.
• To assess the combined diagnostic utility of PET/CT and mpMRI compared to mpMRI alone.

Main Methods:

• A retrospective single-center study included 35 men investigated for radiorecurrence between 2016 and 2022.
• All patients underwent Gallium-68 PSMA PET/CT, mpMRI, and prostate biopsy.
• PET/CT images were interpreted independently by two blinded expert readers; diagnostic accuracy was analyzed at the prostate hemigland level.

Main Results:

• Gallium-68 PSMA PET/CT demonstrated high sensitivity (0.89) and negative predictive value (NPV) (0.79), comparable to mpMRI (sensitivity 0.72, NPV 0.59).
• The combination of PET/CT and mpMRI significantly improved sensitivity (0.98) and NPV (0.93) compared to mpMRI alone (P = 0.003 and P < 0.001, respectively).
• mpMRI missed 28% of cancers, 92% of which were detected by PET/CT.

Conclusions:

• Gallium-68 PSMA PET/CT offers high sensitivity for detecting intraprostatic radiorecurrence, similar to mpMRI.
• The combined use of Gallium-68 PSMA PET/CT and mpMRI significantly enhances diagnostic accuracy and NPV over mpMRI alone.
• Gallium-68 PSMA PET/CT is a valuable tool for diagnosing localized prostate cancer recurrence.