Fluorine-18-labelled Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography or Magnetic Resonance Imaging to Diagnose and Localise Prostate Cancer. A Prospective Single-arm Paired Comparison (PEDAL).

Multiparametric magnetic resonance imaging (mpMRI) of the prostate is used for prostate cancer diagnosis. However, mpMRI has lower sensitivity for small tumours. Prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA-PET/CT) offers increased sensitivity over conventional imaging. This study aims to determine whether the diagnostic accuracy of 18F-DCFPyL PSMA-PET/CT was superior to that of mpMRI for detecting prostate cancer (PCa) at biopsy. Between 2020 and 2021, a prospective multicentre single-arm phase 3 imaging trial enrolled patients with clinical suspicion for PCa to have both mpMRI and PSMA-PET/CT (thorax to thigh), with reviewers blinded to the results of other imaging. Multiparametric MRI was considered positive for Prostate Imaging Reporting and Data System (PIRADS) 3-5. PSMA-PET/CT was assessed quantitatively (positive maximum standardised uptake value [SUVmax] >7) and qualitatively (five-point lexicon of certainty). Patients underwent targeted and systematic biopsy, with the technique at the discretion of the treating urologist. Clinically significant PCa (csPCa) was defined as International Society of Urological Pathology grade group (GG) ≥2. The primary outcome was the diagnostic accuracy for detecting PCa, reported as sensitivity, specificity, negative predictive value (NPV), and area under the curve (AUC) of the receiver operating curve. The secondary endpoints included a comparison of the diagnostic accuracy for detecting csPCa, assessing gains in combining PMSA-PET/CT with mpMRI to mpMRI alone. Of the 236 patients completing both mpMRI and PSMA-PET/CT, 184 (76.7%) had biopsy. Biopsy histology was benign (n = 73), GG 1 (n = 27), and GG ≥2 (n = 84). The diagnostic accuracy of mpMRI for detecting PCa (AUC 0.76; 95% confidence interval [CI] 0.69, 0.82) was higher than that of PSMA-PET/CT (AUC 0.63; 95% CI 0.56, 0.70, p = 0.03). The diagnostic accuracy of mpMRI for detecting csPCa (AUC 0.72; 95% CI 0.67, 0.78) was higher than that of PSMA-PET/CT (AUC 0.62; 95% CI 0.55, 0.69) but not statistically significant (p = 0.27). A combination of PSMA-PET/CT and mpMRI showed excellent sensitivity (98.8%, 95% CI 93.5%, 100%) and NPV (96%, 95% CI 79.6%, 99.9%) over mpMRI alone (86.9% and 80.7%, respectively, p = 0.01). Thirty-two patients (13.6%) had metastatic disease. They tended to be older (68.4 vs 65.1 yr, p = 0.023), and have higher prostate-specific antigen (PSA; median PSA 9.6 vs 6.2ng/ml, p < 0.001) and abnormal prostate on digital rectal examination (78.2% vs 44.1%, p < 0.001). Multiparametric MRI had superior diagnostic accuracy to PSMA-PET/CT for detecting PCa, though the difference is not significant in case of csPCa detection. A combination of mpMRI and PSMA-PET/CT showed improved sensitivity and NPV. PSMA-PET/CT could be considered for diagnostic use in patients unable to have mpMRI or those with concerning clinical features but negative mpMRI. In this trial, we compared the ability of 18F-labelled prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA-PET/CT) with that of multiparametric magnetic resonance imaging (mpMRI) to diagnose prostate cancer by biopsy in a prostate-specific antigen screening population. We found that MRI was superior to PSMA to diagnose prostate cancer, though there was no difference in ability to diagnose clinically significant prostate cancer. PSMA-PET/CT could be considered for diagnostic use in patients unable to have mpMRI or those with concerning clinical features but negative mpMRI. Combining MRI with PSMA-PET increases the negative predictive value over MRI alone and may help men avoid invasive prostate biopsy.

Wong LM ，Sutherland T ，Perry E ，Tran V ，Spelman T ，Corcoran N ，Lawrentschuk N ，Woo H ，Lenaghan D ，Buchan N ，Bax K ，Symons J ，Saeed Goolam A ，Chalasani V ，Hegarty J ，Thomas L ，Christov A ，Ng M ，Khanani H ，Lee SF ，Taubman K ，Tarlinton L ... -  《European Urology Oncology》

Protocol for the PRIMARY clinical trial, a prospective, multicentre, cross-sectional study of the additive diagnostic value of gallium-68 prostate-specific membrane antigen positron-emission tomography/computed tomography to multiparametric magnetic reson

Primary objectives: To determine the additive value of gallium-68 prostate-specific membrane antigen (PSMA) positron emission topography (PET)/computed tomography (CT) when combined with multiparametric magnetic resonance imaging (mpMRI) detecting clinically significant prostate cancer (csPCa) in men undergoing initial biopsy for suspicion of PCa, and to determine the proportion of men who could have avoided prostate biopsy with positive mpMRI (PI-RADS ≥3) but negative PSMA-PET/CT. Secondary objectives: To determine the proportion of men who had csPCa detected only by PSMA-PET/CT or only by systematic prostate biopsy; to compare index lesions by template biopsies vs targeted lesions identified on mpMRI or PSMA-PET/CT; to assess whether there may be health economic benefit or harm if PSMA-PET/CT is incorporated into the diagnostic algorithm; and to develop a nomogram which combines clinical, imaging and biomarker data to predict the likelihood of csPCa. The PRIMARY trial is a multicentre, prospective, cross-sectional study that meets the criteria for level 1 evidence in diagnostic test evaluation. PRIMARY will investigate if a limited (pelvic-only) PSMA-PET/CT in combination with routine mpMRI can reliably discriminate men with csPCa from those without csPCa. We conducted a power calculation based on pilot data and will recruit up to 600 men who will undergo PSMA-PET/CT (the index test), mpMRI (standard test) and transperineal template + targeted (PSMA-PET/CT and/or mpMRI) biopsies (reference test). The conduct and reporting of the mpMRI and PSMA-PET/CT will be blinded to each other. The PRIMARY trial will measure and compare sensitivity, specificity, positive predictive value and negative predictive value of both mpMRI and PSMA-PET/CT vs targeted prostrate biopsy. The results will be used to determine the proportion of men who could safely avoid biopsy without compromising detection of csPCa. Furthermore, we will assess whether there is a health economic benefit in incorporating PSMA-PET/CT into the diagnostic algorithm. This trial will provide robust prospective data to determine the diagnostic ability of PSMA-PET/CT used in addition to mpMRI. It will establish if certain patients can avoid biopsy in the investigation of PCa.

Amin A ，Blazevski A ，Thompson J ，Scheltema MJ ，Hofman MS ，Murphy D ，Lawrentschuk N ，Sathianathen N ，Kapoor J ，Woo HH ，Chalasani V ，Rasiah K ，van Leeuwen PJ ，Tang R ，Cusick T ，Stricker P ，Emmett L ... -  《-》

Combined Utility of (68)Ga-Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography and Multiparametric Magnetic Resonance Imaging in Predicting Prostate Biopsy Pathology.

68Gallium-labelled prostate-specific membrane antigen positron emission tomography (68Ga-PSMA-11 PET) is a valuable staging tool, but its utility in characterising primary prostate cancer remains unclear. The maximum standardised uptake value (SUVmax) is a quantification measure of highest radiotracer uptake within PET-avid lesions. To assess the utility of SUVmax in detecting clinically significant prostate cancer (csPCa) on biopsy alone and in combination with multiparametric magnetic resonance imaging (mpMRI). This was a retrospective analysis of 200 men who underwent 68Ga-PSMA-11 PET/CT, mpMRI, and transperineal template prostate biopsy between 2016 and 2018. The primary and secondary outcomes were detection of grade group (GG) 3-5 and GG 2-5 prostate cancer, respectively. We used the Mann-Whitney U test to compare SUVmax by GG, and calculated sensitivity and specificity for csPCa detection via 68Ga-PSMA-11 PET/CT, mpMRI, and both. Multivariable logistic regression analyses were used to identify predictors of csPCa on biopsy. The median SUVmax was greater for GG 3-5 tumours (6.40, interquartile range [IQR] 4.47-11.0) than for benign and GG 1-2 tumours (3.14, IQR 2.55-3.91; p <  0.001). The median SUVmax was greater for GG 3 (5.70, IQR 3.68-8.67) than for GG 2 (3.47, IQR 2.70-4.74; p <  0.001). For GG 3-5 disease, sensitivity was 86.5%, 95.9%, and 98.6%, and the negative predictive value (NPV) was 88.4%, 88.5%, and 93.3% using SUVmax ≥4, a Prostate Imaging-Reporting and Data System (PI-RADS) score of 3-5, and both, respectively. This combined model detected more GG 3-5 disease than mpMRI alone (98.6% vs 95.9%; p =  0.04). SUVmax was an independent predictor of csPCa for GG 3-5 disease only (odds ratio 1.27 per unit, 95% confidence interval 1.13-1.45). Our results are limited by the retrospective study design. Greater SUVmax on 68Ga-PSMA-11 PET/CT is associated with detection of GG 3-5 cancer on biopsy. The combination of PI-RADS score and SUVmax provides higher sensitivity and NPV than either alone. 68Ga-PSMA-11 PET/CT may be useful alongside mpMRI in improving risk stratification for localised disease. The amount of a radioactive tracer taken up in the prostate during a type of scan called PET (positron emission tomography) can predict whether aggressive prostate cancer is likely to be found on biopsy. This may complement the more usual type of scan, MRI (magnetic resonance imaging), used to detect prostate cancer.

Kalapara AA ，Ballok ZE ，Ramdave S ，O'Sullivan R ，Ryan A ，Konety B ，Grummet JP ，Frydenberg M ... -  《European Urology Oncology》

The Additive Diagnostic Value of Prostate-specific Membrane Antigen Positron Emission Tomography Computed Tomography to Multiparametric Magnetic Resonance Imaging Triage in the Diagnosis of Prostate Cancer (PRIMARY): A Prospective Multicentre Study.

Multiparametric magnetic resonance imaging (MRI) is validated for the detection of clinically significant prostate cancer (csPCa), although patients with negative/equivocal MRI undergo biopsy for false negative concerns. In addition, 68Ga-PSMA-11 positron emission tomography/computed tomography (prostate-specific membrane antigen [PSMA]) may also identify csPCa accurately. This trial aimed to determine whether the combination of PSMA + MRI was superior to MRI in diagnostic performance for detecting csPCa. A prospective multicentre phase II imaging trial was conducted. A total of 296 men were enrolled with suspected prostate cancer, with no prior biopsy or MRI, recent MRI (6 mo), and planned transperineal biopsy based on clinical risk and MRI. In all, 291 men underwent MRI, pelvic-only PSMA, and systematic ± targeted biopsy. Sensitivity, specificity, and predictive values (negative predictive value [NPV] and positive predictive value) for csPCa were determined for MRI, PSMA, and PSMA + MRI. PSMA + MRI was defined as negative for PSMA negative Prostate Imaging Reporting and Data System (PI-RADS) 2/3 and positive for either MRI PI-RADS 4/5 or PSMA positive PI-RADS 2/3; csPCa was any International Society of Urological Pathology (ISUP) grade group ≥2 malignancy. Of the patients, 56% (n = 162) had csPCa; 67% had PI-RADS 3-5, 73% were PSMA positive, and 81% were combined PSMA + MRI positive. Combined PSMA + MRI improved NPV compared with MRI alone (91% vs 72%, test ratio = 1.27 [1.11-1.39], p < 0.001). Sensitivity also improved (97% vs 83%, p < 0.001); however, specificity was reduced (40% vs 53%, p = 0.011). Five csPCa cases were missed with PSMA + MRI (four ISUP 2 and one ISUP 3). Of all men, 19% (56/291) were PSMA + MRI negative (38% of PI-RADS 2/3) and could potentially have avoided biopsy, risking delayed csPCa detection in 3.1% men with csPCa (5/162) or 1.7% (5/291) overall. PSMA + MRI improved NPV and sensitivity for csPCa in an MRI triaged population. Further randomised studies will determine whether biopsy can safely be omitted in men with a high clinical suspicion of csPCa but negative combined imaging. The combination of magnetic resonance imaging (MRI) + prostate-specific membrane antigen positron emission tomography reduces false negatives for clinically significant prostate cancer (csPCa) compared with MRI, potentially allowing a reduction in the number of prostate biopsies required to diagnose csPCa.

Emmett L ，Buteau J ，Papa N ，Moon D ，Thompson J ，Roberts MJ ，Rasiah K ，Pattison DA ，Yaxley J ，Thomas P ，Hutton AC ，Agrawal S ，Amin A ，Blazevski A ，Chalasani V ，Ho B ，Nguyen A ，Liu V ，Lee J ，Sheehan-Dare G ，Kooner R ，Coughlin G ，Chan L ，Cusick T ，Namdarian B ，Kapoor J ，Alghazo O ，Woo HH ，Lawrentschuk N ，Murphy D ，Hofman MS ，Stricker P ... -  《-》

Establishment and prospective validation of an SUV(max) cutoff value to discriminate clinically significant prostate cancer from benign prostate diseases in patients with suspected prostate cancer by (68)Ga-PSMA PET/CT: a real-world study.

Background and Aims: The aims of this study were to establish a maximum standardized uptake value (SUVmax) cutoff to discriminate clinically significant prostate cancer (csPCa) from benign prostate disease (BPD) by 68Ga-labeled prostate-specific membrane antigen (68Ga-PSMA-11) positron emission tomography/computed tomography (PET/CT) in patients with suspected prostate cancer (PCa), and to perform a prospective real-world validation of this cutoff value. Methods: The study included a training cohort to identify an SUVmax cutoff value and a prospective real-world cohort to validate it. A retrospective analysis assessed 135 patients with suspected PCa in a large tertiary care hospital in China who underwent 68Ga-PSMA-11 PET/CT. All patients were suspected of having PCa based on symptoms, digital rectal examination (DRE), total prostate-specific antigen (tPSA) level, and multiparameter magnetic resonance imaging (mpMRI). The 68Ga-PSMA PET/CT results were evaluated using histopathological results from transrectal ultrasound-guided 12-core biopsy with necessary targeted biopsy as references. Patients with Gleason scores (GS) ≥7 from the biopsy results were diagnosed with csPCa, and patients with negative biopsy and follow-up results were diagnosed with BPD. Receiver operating characteristic (ROC) curve analysis was used to identify the optimal SUVmax cutoff value. The cutoff value was prospectively validated in 58 patients with suspected PCa. The diagnostic benefits of the cutoff value for clinical decision making were also evaluated. Results: According to ROC curve analysis, the most appropriate SUVmax cutoff value for discriminating csPCa from BPD was 5.30 (sensitivity, 85.85%; specificity, 86.21%; area under the curve [AUC], 0.893). The cutoff achieved a sensitivity of 83.33%, a specificity of 81.25%, a positive predictive value (PPV) of 92.11%, a negative predictive value (NPV) of 65.00%, and an accuracy of 82.76% in the prospective validation cohort. Metastases were used as an indicator to reduce false negative results in patients with SUVmax ≤ 5.30. In patients without metastases, an SUVmax value of 5.30 was also the best cutoff to diagnose localized csPCa (sensitivity, 80.43%; specificity, 86.21%; AUC, 0.852). The cutoff discriminated localized csPCa from BPD with a sensitivity of 76.19%, a specificity of 81.25%, a PPV of 84.21%, an NPV of 72.22%, and an accuracy of 78.38% in the prospective validation cohort. The cutoff, combined with metastases, achieved an accuracy of 89.12% in all patients, increasing accuracy by 8.29% and reducing equivocal results compared with manual reading. There was a strong correlation between SUVmax and PSMA expression (rs = 0.831, P < 0.001) and a moderate correlation between SUVmax and GS (rs = 0.509, P < 0.001). The PSMA expression and SUVmax values of patients with csPCa were significantly higher than those of patients with BPD (P < 0.001). Conclusion: We established and prospectively validated the best SUVmax cutoff value (5.30) for discriminating csPCa from BPD with high accuracy in patients with suspected PCa. 5.30 is an effective cutoff to discriminate csPCa patients with or without metastases. The cutoff may provide a potential tool for the precise identification of csPCa by 68Ga-PSMA PET/CT, ensuring high accuracy and reducing equivocal results.

Jiao J ，Kang F ，Zhang J ，Quan Z ，Wen W ，Zhao X ，Ma S ，Wu P ，Yang F ，Guo W ，Yang X ，Yuan J ，Shi Y ，Wang J ，Qin W ... -  《Theranostics》