Prostate-specific Membrane Antigen Positron Emission Research Articles

Detection rate of 18F-rhPSMA-7.3 PET in patients with suspected prostate cancer recurrence: Results from a phase 3, prospective, multicenter study (SPOTLIGHT)

9 Background: 18F-labeled prostate-specific membrane antigen (PSMA) positron emission tomography (PET) ligands offer a longer half-life and improved spatial resolution compared with 68Ga-PSMA. Here, we report the detection rate (DR) of 18F-rhPSMA-7.3, a novel high affinity theranostic PET ligand with potential for low bladder activity. Methods: SPOTLIGHT (NCT04186845) assessed the coprimary endpoints of patient level Correct Detection Rate (CDR - % of all patients scanned with ≥1 true positive lesion) and region level Positive Predictive Value (all PET positive regions combined) of 18F-rhPSMA-7.3 using histopathology and/or conventional imaging as a composite Standard of Truth (SoT). These metrics were also evaluated in a subset of patients with a histopathology-only SoT. Prespecified statistical thresholds of at least 36.5% and 62.5% were set for CDR and PPV, respectively. Overall DR stratified by PSA was also documented. Men with prostate cancer recurrence underwent PET 50-70 minutes after IV administration of 296 MBq 18F-rhPSMA-7.3. Image guided biopsies of PET lesions took place ≤60 days post-PET and any confirmatory imaging took place ≤90 days. Three blinded central readers evaluated the scans with majority read accepted as final interpretation. A separate Truth Panel established SoT for each patient. Results: The overall DR in the 389 men (median [range] PSA, 1.10 [0.03-134.6] ng/mL) who had an evaluable 18F-rhPSMA-7.3 scan is 83% by majority read (See Table). In the 366 men (median [range] PSA, 1.27 [0.03-134.6] ng/mL) with a composite SoT, the patient level CDR is 56.8% (95% CI, 51.6-62.0), meeting the prespecified threshold. The region level PPV is 59.7% (54.7-64.7), not meeting the prespecified threshold. In the subset of patients with a histopathology-only SoT, the patient level CDR and region level PPV are higher at 81.2% (69.9-89.6) and 71.6% (62.5-80.7), respectively. Both of these values would have met the prespecified thresholds. Conclusions: 18F-rhPSMA-7.3 has a clinically meaningful CDR that meets the prespecified threshold. While the region level PPV does not meet the prespecified threshold, the data in patients with a composite SoT are limited by the high proportion of prostate/bed scans (92%) that relied on conventional imaging, a suboptimal SoT. For the subset of patients with the more robust histopathology SoT for at least one region per patient, a high PPV is seen and the lower bound of the 95% CI would have exceeded the prespecified threshold. Together, these data support the clinical utility of 18F-rhPSMA-7.3 PET in men with recurrent prostate cancer across a wide PSA range. Clinical trial information: NCT04186845. [Table: see text]

Dual-tracer PET/CT-targeted, mpMRI-targeted, systematic biopsy, and combined biopsy for the diagnosis of prostate cancer.

34 Background: Growing evidence proved the efficacy of multiparametric MRI (mpMRI) and prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT)-guided targeted biopsy (TB) in prostate cancer (PCa) diagnosis, but there is no direct comparison between mpMRI-TB and PSMA PET/CT-TB. Gastrin-releasing peptide receptor (GRPR) highly expressed in PCa, which can compensate for the unstable expression of PSMA in PCa. Therefore, we designed a study to compare the efficiency of mpMRI-TB, dual-Tracer (GRPR and PSMA) PET/CT-TB, systematic biopsy, and combined biopsy for the diagnosis of prostate cancer. Methods: 112 suspicious PCa patients were enrolled from September 2020 and June 2021 in this prospective and comparative effectiveness study. Patients with positive dual-tracer PET/CT or mpMRI results underwent TB and all enrolled patients underwent SB after TB. The primary outcome was the detection rates of PCa in different biopsy strategies. Secondary outcomes were the performance of three imaging methods, omission diagnostic rates, and upgrading and downgrading of biopsy samples relative to those of prostatectomy specimens in different biopsy strategies. Results: In 112 men, clinically significant PCa (grade group≥2) accounted for 34.82% (39/112) and nonclinically significant PCa (grade group = 1) accounted for 4.46% (5/112). 68Ga-PSMA PET/CT-TB achieved higher PCa detection rate (69.77%) and positive ratio of biopsy cores (0.44) compared with SB (39.29% and 0.12) and mpMRI-TB (36.14% and 0.23), respectively (P < 0.005). Dual-tracer PET/CT as a triage test avoided 52.67% (59/112) unnecessary biopsy, whereas dual-tracer PET/CT-TB plus SB achieved high detection rate (77.36%) without misdiagnosis of csPCa. Conclusions: Dual-tracer PET/CT could screen patients for avoiding unnecessary biopsy. Dual-tracer PET/CT-TB plus SB might be a more effective and promising strategy for definite diagnosis of clinically significant PCa than mpMRI-TB.

Application of 18F Prostate-Specific Membrane Antigen Positron Emission Tomography/Computed Tomography in Monitoring Gastric Metastasis and Cancer Thrombi from Renal Cell Carcinoma.

Background Renal cell carcinoma (RCC) with gastric metastasis is rare, particularly accompanied by multiple cancer thrombi. Methods We reported a 66-year-old man with a history of a right radical nephrectomy because of RCC. The patient underwent 18F prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) scanning after 6 months of targeted therapy because of gastric metastasis and cancer thrombi. We conducted a systematic review of the literature and identified 73 cases of RCC with gastric metastasis. We analyzed the clinicopathological characteristics, therapies, and outcomes of patients. Results 18F-PSMA PET/CT showed a large mass in the gastric fundus and cancer thrombi in the right atrium, inferior vena cava, and splenic vein with intense tracer uptake. Other metastases with increased tracer uptake included multiple bones and abdominal lymph nodes. The majority of gastric metastasis of RCC were men (53/73, 72.6%), with a median age at presentation of 67 (from 48 to 87) years. Gastric metastasis of RCC was mainly metachronous, and presented with small polyps or mass appearance and often accompanied by multiple-site metastases and gastrointestinal symptoms. An overall median interval between nephrectomy and diagnosis of gastric metastasis was 6 (from 0.1 to 23) years, and an overall median survival time was 14 (from 0.25 to 72) months. The median interval time of solitary gastric metastasis was longer than gastric metastasis with multiple-site metastases (7 vs.5 years; P=0.034). Patients with gastric and multiple-site metastases had higher mortality than patients with solitary metastasis (17 vs.1; P=0.028). The patients with synchronous gastric metastasis had a shorter survival time than metachronous gastric metastasis (6 vs.17 months; P=0.018). Conclusions Postoperative follow-up of multiple imaging modalities to monitor recurrence and metastasis is necessary and important. PSMA PET/CT can improve the detection sensitivity of RCC, especially in metastatic clear cell renal cell carcinoma (ccRCC), and could provide a basis for disease staging, restaging, and therapeutic efficacy evaluation.

Superscan Appearance of 68Ga PSMA PET/CT in a Patient with Refractory Prostate Cancer.

A 64-year-old male patient with metastatic prostate carcinoma diagnosis received lutetium-177 prostate-specific membrane antigen (PSMA) treatment; however, his disease progressed. Herein, presented the final images of the patient that demonstrated a superscan appearance in the Gallium-68 PSMA positron emission tomography/computed tomography, which is a rare phenomenon.

A0192 - Restaging prostate-specific membrane antigen positron emission tomography/ computed tomography is associated with improved oncological outcome in men who underwent salvage radiation therapy for biochemically recurrent prostate cancer

A0192 - Restaging prostate-specific membrane antigen positron emission tomography/ computed tomography is associated with improved oncological outcome in men who underwent salvage radiation therapy for biochemically recurrent prostate cancer

Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography Is Associated with Improved Oncological Outcome in Men Treated with Salvage Radiation Therapy for Biochemically Recurrent Prostate Cancer

BackgroundRadiolabeled prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has shown superior diagnostic accuracy to conventional imaging for the detection of prostate cancer deposits . Consequently, clinical management changes have been reported in patients with biochemical recurrence (BCR) of disease after robot-assisted radical prostatectomy (RARP). We hypothesized that, due to the exclusion of patients with metastatic disease on PSMA-PET/CT, those who underwent local salvage radiation therapy (SRT) after restaging PSMA-PET/CT for BCR may have better oncological outcomes than patients who underwent “blind” SRT. ObjectiveTo compare the oncological outcome of a patient cohort that underwent PSMA-PET imaging prior to SRT with that of a patient cohort that did not have PSMA-PET imaging before SRT. Design, setting, and participantsWe included 610 patients who underwent SRT, of whom 298 underwent PSMA-PET/CT prior to SRT and 312 did not. No additional hormonal therapy was prescribed. Outcome measurements and statistical analysisTo compare both cohorts, case-control matching was performed, using the prostate-specific antigen (PSA) value at the initiation of SRT, pathological grade group, pathological T stage, surgical margin status, and biochemical persistence after RARP as matching variables. The outcome variable was biochemical progression at 1 yr after SRT, defined as either a rise of PSA ≥0.2 ng/ml above the nadir after SRT or the start of additional treatment. Results and limitationsAfter case-control matching, 216 patients were matched in both cohorts (108 patients per cohort). In the patient cohort without PSMA-PET/CT prior to SRT, of 108 patients, 23 (21%) had biochemical progression of disease at 1 yr after SRT, compared with nine (8%) who underwent restaging PSMA-PET/CT prior to SRT (p = 0.007). ConclusionsPSMA-PET/CT is found to be associated with an improved oncological outcome in patients who undergo SRT for BCR after RARP. Patient summaryPerforming prostate-specific membrane antigen positron emission tomography/computed tomography imaging in patients with biochemical recurrence of disease after robot-assisted radical prostatectomy, before initiating salvage radiation therapy, resulted in improved short-term oncological outcomes.

Considerations on Integrating Prostate-Specific Membrane Antigen Positron Emission Tomography Imaging Into Clinical Prostate Cancer Trials by National Clinical Trials Network Cooperative Groups.

As prostate-specific membrane antigen (PSMA) positron emission tomography (PET) becomes increasingly available in the United States, the greater sensitivity of the technology in comparison to conventional imaging poses challenges for clinical trials. The NCI Clinical Imaging Steering Committee (CISC) PSMA PET Working Group was convened to coordinate the identification of these challenges in various clinical scenarios and to develop consensus recommendations on how best to integrate PSMA PET into ongoing and upcoming National Clinical Trials Network (NCTN) trials. NCI CISC and NCI Genitourinary Steering Committee members and leadership nominated clinicians, biostatisticians, patient advocates, and other imaging experts for inclusion in the PSMA PET Working Group. From April to July 2021, the working group met independently and in conjunction with the CISC to frame challenges, including stage migration, response assessment, trial logistics, and statistical challenges, and to discuss proposed solutions. An anonymous, open-ended survey was distributed to members to collect feedback on challenges faced. Representatives from each NCTN group were invited to present an overview of affected trials. From these discussions, the consensus document was developed and circulated for the inclusion of multiple rounds of feedback from both the Working Group and CISC. The current consensus document outlines the key challenges for clinical prostate cancer trials resulting from the increasing availability of PSMA PET. We discuss implications for patient selection and definition of end points and provide guidance and potential solutions for different clinical scenarios, particularly with regard to best practices in defining eligibility criteria and outcome measures. This article provides guidance regarding clinical trial design and conduct, and the interpretation of trial results.

Testicular metastasis in prostate cancer: A rare case of testicular metastasis diagnosed with 68Ga-PSMA and review of the literature

Objective: Testicular metastasis in prostate cancer is a rare entity. We aimed to report the case where this rare condition was diagnosed with Gallium prostate-specific membrane antigen–positron emission tomography/computed tomography (68Ga-PSMA-PET/CT). Subjects/patients and methods: A 68-year-old male with a prostate adenocarcinoma presented with testicular metastasis. The patient was diagnosed with 68Ga-PSMA-PET/CT, and bilateral inguinal orchiectomy was performed. Herein, our case is presented, and a short review of the literature is carried out. Conclusion: 68Ga-PSMA-PET/CT is an effective imaging method for detecting rare metastases. Level of evidence: 4

Patterns of Prostate Cancer Recurrence After Brachytherapy Determined by Prostate-Specific Membrane Antigen–Positron Emission Tomography and Computed Tomography Imaging

The aim of this study was to characterize the patterns of prostate cancer recurrence after brachytherapy (BT) using 2-(3-[1-carboxy-5-([6-18F-fluoropyridine-3-carbonyl]-amino)-pentyl]-ureido)-pentanedioic acid ([18F]DCFPyL) prostate-specific membrane antigen (PSMA) positron emission tomography (PET) and computed tomography (CT) imaging. Patients were selected from an ongoing prospective institutional trial investigating the use of [18F]DCFPyL PSMA PET and CT in recurrent prostate cancer (NCT02899312). This report included patients who underwent BT (either monotherapy or boost) and experienced a biochemical failure (BF) defined by the Phoenix definition (prostate-specific antigen [PSA] > 2 ng/mL above nadir). Between March 2017 and April 2020, 670 patients underwent [18F]DCFPyL PSMA PET and CT imaging. Of these 670 patients, 93 were treated with BT; 73 underwent monotherapy, and 20 underwent BT boost (19 low-dose rate and 1 high-dose rate). To report on patterns of recurrence outcomes, 86 patients (median prescan PSA 6.0) with a positive [18F]DCFPyL PSMA PET and CT scan and true BF were included. The most common location of relapse was local; 62.8% had a component of local failure (defined as prostate and/or seminal vesicles), and 46.5% had isolated local failure only, with no other sites of involvement. Regional failure occurred in 40.7% of patients, and 36.0% had metastatic failure. Isolated local recurrence was seen in 54.3% of monotherapy patients versus only in 12.5% of boost patients. Metastatic failure was seen in 28.6% of monotherapy patients versus 68.8% of the boost patients. Local recurrences (69.0%) were found within the same prostate biopsy sextant involved with the tumor at diagnosis, and 76.0% of patients with seminal vesicle recurrences had prostate-base involvement at diagnosis. Contrary to previous evidence, our study suggests that in prostate BT patients with biochemical recurrence, the most common site of failure is local for the patients treated with monotherapy and metastatic for patients treated with a combination of external beam radiation and BT boost.

Prostate-specific Membrane Antigen Positron Emission Tomography (PSMA-PET) and Gleason grading system based Artificial Intelligence (AI) model in diagnosis and staging of prostate cancer

Introduction: Prostate cancer is the second-most commonly occurring cancer and the fifth major cause of death among men worldwide. Early diagnosis and treatment planning are very crucial in reducing the mortality rate due to prostate cancer. Gleason grading is the most used prostate cancer prognosis tool by doctors for a long time. It is used to determine the aggressiveness of the cancer for planning treatment options. The process requires very trained pathologists to look at multiple biopsy samples under the microscope and assign a grade to the cancer based on its severity.Methods: In this work, we are adding Gleason grading capabilities to prostate-specific membrane antigen positron emission tomography/ computed tomography (PSMA PET-CT) scans for tumor habitats and classify them as aggressive or indolent type. Tagging habitats with Gleason grade to categorize them as aggressive or indolent type helps in biopsy planning to extract the right tissue samples and tagging helps to target aggressive tumors during radiation therapy. We have developed a machine learning-based model to automatically classify tumor habitat regions of interest from PSMA PET and CT imaging data into Gleason grade groups of indolent and aggressive.Results: The 68Ga-PSMA PET-CT scans are very effective in detecting the presence of different habitats within the tumor with distinct volumes, each with a specific combination of flow, cell density, necrosis, and edema. Habitat distribution through tumor heterogeneity analysis in patients with prostate cancers can be enabled to discriminate between cancers that progress quickly and those that are more indolent.Conclusion: We have developed an AI model to classify habitat tumors present in the gross tumor volume into indolent and aggressive types based on the ground truth generated using Gleason grade groups on pathology samples by Healthcare Global Cancer Hospital, Bangalore, India. Habitat analysis helps radiotherapists to target active tumor cells within gross tumor volume and helps in selecting the right tissue for performing biopsy. The currently developed model is performing with an overall accuracy of 90% on test data.

F-18 PSMA Uptake in Male Breast Cancer during Restaging Evaluation of Carcinoma Prostate.

Fluorine-18 prostate-specific membrane antigen (PSMA) positron emission tomography-computed tomography scan is widely used for restaging of prostate cancer. We present a case where false-positive PSMA uptake was seen in metachronous carcinoma breast during restaging workup of carcinoma prostate.

Frequency and intensity of [18F]-PSMA-1007 uptake after COVID-19 vaccination in clinical PET.

Objectives:To assess the frequency and intensity of [18F]-prostate-specific membrane antigen (PSMA)-1007 axillary uptake in lymph nodes ipsilateral to COVID-19 vaccination with BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) in patients with prostate cancer referred for oncological [18F]-PSMA positron emission tomography (PET)/CT or PET/MR imaging.Methods:126 patients undergoing [18F]-PSMA PET/CT or PET/MR imaging were retrospectively included. [18F]-PSMA activity (maximum standardized uptake value) of ipsilateral axillary lymph nodes was measured and compared with the non-vaccinated contralateral side and with a non-vaccinated negative control group. [18F]-PSMA active lymph node metastases were measured to serve as quantitative reference.Results:There was a significant difference in maximum standardized uptake value in ipsilateral and compared to contralateral axillary lymph nodes in the vaccination group (n = 63, p < 0.001) and no such difference in the non-vaccinated control group (n = 63, p = 0.379). Vaccinated patients showed mildly increased axillary lymph node [18F]-PSMA uptake as compared to non-vaccinated patients (p = 0.03). [18F]-PSMA activity of of lymph node metastases was significantly higher (p < 0.001) compared to axillary lymph nodes of vaccinated patients.Conclusion:Our data suggest mildly increased [18F]-PSMA uptake after COVID-19 vaccination in ipsilateral axillary lymph nodes. However, given the significantly higher [18F]-PSMA uptake of prostatic lymph node metastases compared to “reactive” nodes after COVID-19 vaccination, no therapeutic and diagnostic dilemma is to be expected.Advances in knowledge:No specific preparations or precautions (e.g. adaption of vaccination scheduling) need to be undertaken in patients undergoing [18F]-PSMA PET imaging after COVID-19 vaccination.

Radiolabeling of PSMA-617 with 89Zr: A novel use of DMSO to improve radiochemical yield and preliminary small-animal PET results

IntroductionNovel diagnostic and therapeutic options are urgently needed for patients with metastatic castration-resistant prostate cancer (CRPC). PSMA-617 is one of the most promising ligands that bind to prostate specific membrane antigen (PSMA), the cell surface biomarker of CRPC. Of the radiolabeled PSMA ligands developed to date, [68Ga]Ga-PSMA-617 is most commonly used for PSMA positron emission tomography (PET) prior to radioligand therapy (RLT) with [177Lu]Lu-PSMA-617. However, the presence of 68Ga radioactivity (half-life 68 m) in urine at the early PET imaging time point complicates optimization of the therapeutic dose of PSMA-617 labeled with 177Lu (half-life 6.7 d). Thus, PET imaging with the long-lived positron emitter 89Zr (half-life 3.3 d) would be better suited in order to optimize the dose of [177Lu]Lu-PSMA-617 as 89Zr PET allows scans after excretion of the radioactive urine. Until now, PSMA-617 could not be radiolabeled with 89Zr with high radiochemical yield due to poor incorporation of 89Zr into 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). Here we report a novel method for radiolabeling PSMA-617 with 89Zr and the preliminary results of small-animal PET with [89Zr]Zr-PSMA-617. MethodsWe labeled PSMA-617 with 89Zr in a 1:1 mixture of DMSO and HEPES buffer at 90 °C for 30 min, followed by quality control analysis by HPLC. We then determined the dissociation constant (Kd) and logD values of [89Zr]Zr-PSMA-617. We obtained PET images of [89Zr]Zr-PSMA-617 at 24 h in mice bearing both LNCaP (PSMA-positive) and PC-3 (PSMA-negative) tumors (N = 5). The ex vivo [89Zr]Zr-PSMA-617 biodistribution was then examined separately using tissue samples of LNCaP-bearing mice at 2 h (N = 4) and 24 h (N = 4). Results[89Zr]Zr-PSMA-617 was prepared with a radiochemical yield of 70 ± 9%. The Kd value was 6.8 ± 3.5 nM. The logD value was −4.05 ± 0.20. PET images showed the highest uptake in LNCaP tumors (maximum standardized uptake value, SUVmax = 0.98 ± 0.32) and low uptake in kidneys (SUVmax = 0.18 ± 0.7) due to the absence of urine radioactivity. Conclusion[89Zr]Zr-PSMA-617 was successfully prepared using DMSO and HEPES buffer. [89Zr]Zr-PSMA-617 visualized PSMA-positive LNCaP tumors in the absence of radioactive urine 24 h p.i. Advances in knowledge and implications for patient careThis method of radiolabeling PSMA-617 with 89Zr using DMSO would be suitable for future clinical trials. Prediction of radiation dose by using [89Zr]Zr-PSMA-617 leads to the safe and effective RLT with [177Lu]Lu-PSMA-617.

Clinical Trial Protocol for PSMA-SELECT: A Dutch National Randomised Study of Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography as a Triage Tool for Pelvic Lymph Node Dissection in Patients Undergoing Radical Prostatectomy

The current European Association of Urology (EAU) guidelines for prostate cancer recommend that extended pelvic lymph node dissection (ePLND) should be considered in patients undergoing radical prostatectomy (RP) with a nomogram-based risk of lymph node involvement (LNI) of >5% [1]. However, ePLND during RP may be associated with substantial morbidity and has not been proved to clearly improve oncological outcomes, including prostate cancer–specific survival [2]. Nevertheless, ePLND is still regarded as the gold standard for primary lymph node staging, as it provides information about the pelvic lymph node status that cannot be matched by any imaging modality [1].

Performance of a Prostate-Specific Membrane Antigen Positron Emission Tomography/Computed Tomography–Derived Risk-Stratification Tool for High-risk and Very High-risk Prostate Cancer

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) can detect low-volume, nonlocalized (ie, regional or metastatic) prostate cancer that was occult on conventional imaging. However, the long-term clinical implications of PSMA PET/CT upstaging remain unclear. To evaluate the prognostic significance of a nomogram that models an individual's risk of nonlocalized upstaging on PSMA PET/CT and to compare its performance with existing risk-stratification tools. This cohort study included patients diagnosed with high-risk or very high-risk prostate cancer (ie, prostate-specific antigen [PSA] level >20 ng/mL, Gleason score 8-10, and/or clinical stage T3-T4, without evidence of nodal or metastatic disease by conventional workup) from April 1995 to August 2018. This multinational study was conducted at 15 centers. Data were analyzed from December 2020 to March 2021. Curative-intent radical prostatectomy (RP), external beam radiotherapy (EBRT), or EBRT plus brachytherapy (BT), with or without androgen deprivation therapy. PSMA upstage probability was calculated from a nomogram using the biopsy Gleason score, percentage positive systematic biopsy cores, clinical T category, and PSA level. Biochemical recurrence (BCR), distant metastasis (DM), prostate cancer-specific mortality (PCSM), and overall survival (OS) were analyzed using Fine-Gray and Cox regressions. Model performance was quantified with the concordance (C) index. Of 5275 patients, the median (IQR) age was 66 (60-72) years; 2883 (55%) were treated with RP, 1669 (32%) with EBRT, and 723 (14%) with EBRT plus BT; median (IQR) PSA level was 10.5 (5.9-23.2) ng/mL; 3987 (76%) had Gleason grade 8 to 10 disease; and 750 (14%) had stage T3 to T4 disease. Median (IQR) follow-up was 5.1 (3.1-7.9) years; 1221 (23%) were followed up for at least 8 years. Overall, 1895 (36%) had BCR, 851 (16%) developed DM, and 242 (5%) died of prostate cancer. PSMA upstage probability was significantly prognostic of all clinical end points, with 8-year C indices of 0.63 (95% CI, 0.61-0.65) for BCR, 0.69 (95% CI, 0.66-0.71) for DM, 0.71 (95% CI, 0.67-0.75) for PCSM, and 0.60 (95% CI, 0.57-0.62) for PCSM (P < .001). The PSMA nomogram outperformed existing risk-stratification tools, except for similar performance to Staging Collaboration for Cancer of the Prostate (STAR-CAP) for PCSM (eg, DM: PSMA, 0.69 [95% CI, 0.66-0.71] vs STAR-CAP, 0.65 [95% CI, 0.62-0.68]; P < .001; Memorial Sloan Kettering Cancer Center nomogram, 0.57 [95% CI, 0.54-0.60]; P < .001; Cancer of the Prostate Risk Assessment groups, 0.53 [95% CI, 0.51-0.56]; P < .001). Results were validated in secondary cohorts from the Surveillance, Epidemiology, and End Results database and the National Cancer Database. These findings suggest that PSMA upstage probability is associated with long-term, clinically meaningful end points. Furthermore, PSMA upstaging had superior risk discrimination compared with existing tools. Formerly occult, PSMA PET/CT-detectable nonlocalized disease may be the main driver of outcomes in high-risk patients.

The clinical characteristics of patients with primary non-prostate-specific membrane antigen-expressing prostate cancer on preoperative positron emission tomography/computed tomography.

Prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) is a modern imaging tool used in the diagnosis of prostate cancer (PCa). Approximately 10% of patients who underwent PSMA PET/CT have a biopsy-proven, primary PCa without PSMA expression on PET/CT (non-PSMAPET -expressing PCa), according to a recent systematic review[1]. However, the definition of non-PSMAPET -expression in these studies was poorly defined and no immunohistochemical studies for confirmation of PSMA protein expression were performed. The aim of this retrospective study was to report the prevalence, characteristics, and immunohistochemical assessment of non-PSMAPET -expressing hormone-sensitive PCa in a cohort of 362 patients who underwent PSMA PET/CT and robot-assisted radical prostatectomy (RARP).

Dual-tracer PET/CT-targeted, mpMRI-targeted, systematic biopsy, and combined biopsy for the diagnosis of prostate cancer: a pilot study.

Growing evidence proved the efficacy of multi-parametric MRI (mpMRI) and prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT)-guided targeted biopsy (TB) in prostate cancer (PCa) diagnosis, but there is no direct comparison between mpMRI-TB and PSMA PET/CT-TB. Gastrin-releasing peptide receptor (GRPR) is highly expressed in PCa, which can compensate for the unstable expression of PSMA in PCa. Therefore, we designed a study to compare the efficiency of mpMRI-TB, dual-tracer (GRPR and PSMA) PET/CT-TB, systematic biopsy, and combined biopsy for the diagnosis of prostate cancer. One hundred twelve suspicious PCa patients were enrolled from September 2020 to June 2021. Patients with anyone of positive dual-tracer PET/CT or mpMRI underwent TB, and all enrolled patients underwent systematic biopsy (SB) after TB. The primary outcome was the detection rates of PCa in different biopsy strategies. Secondary outcomes were the performance of three imaging methods, omission diagnostic rates, and upgrading and downgrading of biopsy samples relative to those of prostatectomy specimens in different biopsy strategies. McNemar's tests and Bonferroni correction in multiple comparisons were used to compare the primary and secondary outcomes. In 112 men, clinically significant PCa (grade group[GG] ≥ 2) accounted for 34.82% (39/112), and nonclinically significant PCa (GG = 1) accounted for 4.46% (5/112). 68Ga-PSMA PET/CT-TB achieved higher PCa detection rate (69.77%) and positive ratio of biopsy cores (0.44) compared with SB (39.29% and 0.12) and mpMRI-TB (36.14% and 0.23), respectively (P < 0.005). Dual-tracer PET/CT screen out patients for avoiding 52.67% (59/112) unnecessary biopsy, whereas dual-tracer PET/CT-TB plus SB achieved high detection rate (77.36%) without misdiagnosis of csPCa. Dual-tracer PET/CT might screen patients for avoiding unnecessary biopsy. Dual-tracer PET/CT-TB plus SB might be a more effective and promising strategy for the definite diagnosis of clinically significant PCa than mpMRI-TB.

Accuracy Versus Impact: The Referee Verdict on Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography for Staging of Prostate Cancer

Accuracy Versus Impact: The Referee Verdict on Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography for Staging of Prostate Cancer

Re: Can Negative Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography Avoid the Need for Pelvic Lymph Node Dissection in Newly Diagnosed Prostate Cancer Patients? A Systematic Review and Meta-analysis with Backup Histology as Reference Standard

Re: Can Negative Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography Avoid the Need for Pelvic Lymph Node Dissection in Newly Diagnosed Prostate Cancer Patients? A Systematic Review and Meta-analysis with Backup Histology as Reference Standard

Prostate-specific Membrane Antigen Positron Emission Tomography, Not Conventional Imaging, Should Be Performed for Primary Staging of High-risk Prostate Cancer

Prostate-specific Membrane Antigen Positron Emission Tomography, Not Conventional Imaging, Should Be Performed for Primary Staging of High-risk Prostate Cancer