Unfavorable MRI But Favorable 68Ga-PSMA PET/MRI for Primary Prostate Cancer Detection

Diagnostic Performance of 68Ga-PSMA PET/MRI in Suspicious Biopsy-naive Prostate Cancer Patients With Favorable Lesion on PET But Unfavorable on MRI for Primary Prostate Cancer Detection: a Pilot Study

This perspective cohort study aims to assess the detection rate of prostate cancer through prostate biopsy within suspicious patients harboring unfavorable multiparametric MRI but favorable 68Ga-PSMA PET/MRI who have had no prior prostate biopsy.

Multiparametric MRI (MpMRI) is currently regarded as the best imaging method to noninvasively identify and characterize prostate cancer (PCa) with the Prostate Imaging Reporting and Data System (PI-RADS) v2. However, there are diagnostic difficulties for suspicious patients with PI-RADS score 3 and not all PCa are equivalently visible on mpMRI. For such patients, other alternative imaging techniques are required to properly characterize and detect PCa.

It has been widely reported that 68Ga-PSMA PET imaging offers excellent performance in detecting primary PCa and is able to noninvasively characterize the aggressiveness of PCa. Recently, integrated PET/MRI, which combines the strengths of both modalities, has been shown to have great potential for influencing clinical practice by providing a more certain map of localized PCa to aid targeted biopsies and therapy.

This perspective cohort study aims to assess the detection rate of PCa through prostate biopsy within suspicious patients harboring unfavorable mpMRI but favorable 68Ga-PSMA PET/MRI who have had no prior prostate biopsy.

Inclusion Criteria:

1. Men more than 18 years old with clinical suspicion of prostate cancer;
2. Serum prostate-specific antigen (PSA) > 4 ng/ml within the previous 3 months;
3. PI-RADS score no more than 3 or normal mpMRI of prostate;
4. Suspicious lesion(s) within prostate on 68Ga-PSMA PET/MRI;
5. no evidence of PSA increase by noncancerous factors, such as catheterization, bladder stones, or urinary tract infection including bacterial prostatitis;
6. Able to provide written informed consent.

Exclusion Criteria:

1. Prior prostate biopsy or prostate surgery;
2. Prior treatment for prostate cancer;
3. Contraindication to MRI or PET (e.g. claustrophobia, pacemaker, estimated glomerular filtration rate ≤ 50mls/min);
4. Contraindication to prostate biopsy.