Diagnostic accuracy of ⁶⁸Ga‐prostate‐specific membrane antigen (PSMA) positron‐emission tomography (PET) and multiparametric (mp)MRI to detect intermediate‐grade intra‐prostatic prostate cancer using whole‐mount pathology: impact of the addition of ⁶⁸Ga‐PSMA PET to mpMRI

Abstract

ObjectiveTo evaluate the ability of prostate-specific membrane antigen (PSMA)-positron-emission tomography (PET)/computed tomography (CT) to detect intermediate-grade intra-prostatic prostate cancer (PCa), and to determine if PSMA-PET improves the diagnostic accuracy of multiparametric magnetic resonance imaging (mpMRI). Patients and MethodsA total of 56 consecutive patients with International Society of Urological Pathology (ISUP) grade 2-3 PCa after radical prostatectomy, who underwent both mpMRI and PSMA-PET CT (hereafter PSMA-PET) preoperatively, were enrolled in this study. The accuracy of PSMA-PET, mpMRI alone, and the two procedures in combination was analysed for identifying ISUP grades 1-3 within a 12-segment model. The accuracy of a combined predictive model (PSMA-PET and mpMRI) was determined. Receiver-operating characteristic curve analysis to determine the optimal standardized uptake value (SUV max ) for PSMA-PET in discriminating between ISUP grades 1 and ≥2 was performed. ResultsOn a per-patient basis, the sensitivities for PSMA-PET and mpMRI in identifying ISUP grades 2-3 PCa were 100% and 97%, respectively. Assessing ISUP grade ≥2 PCa using a 12segment analysis, PSMA-PET demonstrated greater diagnostic accuracy (area under the curve), sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV), with values of 0.91, 88%, 93%, 95% and 85%, respectively, than did mpMRI (Prostate Imaging Reporting and Data System [PI-RADS] 3-5), at 0.79, 68%, 91%, 87%, and 75%, respectively. When used in combination (PSMA-PET and mpMRI PIRADS 4-5), sensitivity, specificity, NPV and PPV were 92%, 90%, 96% and 81%, respectively. The sensitivity for both techniques reduced markedly when assessing ISUP grade 1 PCa (18% for PSMA-PET, 10% for mpMRI). An SUV max value of 3.95 resulted in 94% sensitivity and 100% specificity. ConclusionPSMA-PET is accurate in detecting segments containing intermediate-grade intra-prostatic PCa (ISUP grade ≥ 2), compared with and complementary to mpMRI. By contrast the detection rate for ISUP grade 1 disease for both PSMA-PET and mpMRI was low.

Detection of clinically significant cancer in the anterior prostate by transperineal biopsy

“…Our present study found that PI-RADS score 4 or 5 lesions on MRI were predictive of csPCa, including those in the anterior prostate, reinforcing the role of MRI in the detection of these tumours [7]. With more experience, MRI and, eventually, prostate-specific membrane antigen positron emission tomography may prove a valuable adjunct in detection of csPCa [7,25].…”

Standard and Hypofractionated Dose Escalation to Intraprostatic Tumor Nodules in Localized Prostate Cancer: Efficacy and Toxicity in the DELINEATE Trial

“…8,9 Current advances in positron emission tomography (PET) imaging with the use of prostate-specific membrane antigen (PSMA)-PET/ computed tomography (CT) have been shown to be accurate in detecting segments containing intermediate-grade intraprostatic prostate cancer (International Society of Urological Pathology grade !2). 10 Studies have shown the feasibility of these techniques in DIL identification, 11 with ongoing studies investigating whether this additional information for radiation therapy planning is clinically meaningful.…”

Single‐fraction image‐guided robotic radiosurgery efficiently controls local prostate cancer recurrence after radical prostatectomy

“…PSMA PET/CT allows the exclusion of distant metastases and detection of local recurrence at high sensitivities 20,21 . Also, PSMA PET/CT provides very high specificity, making histopathological confirmation unnecessary in the majority of cases 22,23 . This information can be exploited in order to tailor individualized treatment concepts including the ablation of local recurrent PC tissue or single metastases 10,24 …”