Comparison of preoperative locoregional Ga-68 PSMA-11 PET-CT and mp-MRI results with postoperative histopathology of prostate cancer

68Ga-PSMA-11 PET and mpMRI in the diagnosis of initial lymph node staging of prostate cancer: a head-to-head comparative meta-analysis

Purpose

This meta-analysis evaluates the comparative diagnostic efficacy of 68Ga-prostate-specific membrane antigen-11 PET (68Ga-PSMA-11 PET) and multiparametric MRI (mpMRI) for the initial lymph node staging of prostate cancer.

Methods

We searched PubMed and Embase databases through October 2023 for studies that provide a head-to-head comparison of 68Ga-PSMA-11 PET and mpMRI, using pelvic lymph node dissection as the gold standard. We assessed sensitivity and specificity using the DerSimonian and Laird method, with variance stabilization via the Freeman-Tukey double inverse sine transformation. The quality of included studies was evaluated using the Quality Assessment of Diagnostic Performance Studies (QUADAS-2) tool.

Results

The meta-analysis incorporated 13 articles, involving a total of 1,527 patients. 68Ga-PSMA-11 PET demonstrated an overall sensitivity of 0.73 (95% CI: 0.51-0.91) and a specificity of 0.94 (95% CI: 0.88-0.99). In comparison, mpMRI showed a sensitivity of 0.49 (95% CI: 0.30-0.68) and a specificity of 0.94 (95% CI: 0.88-0.99). Although 68Ga-PSMA-11 PET appeared to be more sensitive than mpMRI, the differences in sensitivity (p = 0.11) and specificity (p = 0.47) were not statistically significant.

Conclusion

Our findings indicated that 68Ga-PSMA-11 PET and mpMRI exhibit similar sensitivity and specificity in the diagnosis of initial lymph node staging of prostate cancer. However, given that most included studies were retrospective, further prospective studies with larger sample sizes are essential to validate these results.

Systematic Review Registration

PROSPERO code is CRD42023495266.

Head-to-head comparison of prostate-specific membrane antigen PET and multiparametric MRI in the diagnosis of pretreatment patients with prostate cancer: a meta-analysis

OBJECTIVES

To compare prostate-specific membrane antigen (PSMA) PET with multiparametric MRI (mpMRI) in the diagnosis of pretreatment prostate cancer (PCa).

METHODS

Pubmed, Embase, Medline, Web of Science, and Cochrane Library were searched for eligible studies published before June 22, 2022. We assessed risk of bias and applicability by using QUADAS-2 tool. Data synthesis was performed with Stata 17.0 software, using the "midas" and "meqrlogit" packages.

RESULTS

We included 29 articles focusing on primary cancer detection, 18 articles about primary staging, and two articles containing them both. For PSMA PET versus mpMRI in primary PCa detection, sensitivities and specificities in the per-patient analysis were 0.90 and 0.84 (p<0.0001), and 0.66 and 0.60 (p <0.0001), and in the per-lesion analysis they were 0.79 and 0.78 (p <0.0001), and 0.84 and 0.82 (p <0.0001). For the per-patient analysis of PSMA PET versus mpMRI in primary staging, sensitivities and specificities in extracapsular extension detection were 0.59 and 0.66 (p =0.005), and 0.79 and 0.76 (p =0.0074), and in seminal vesicle infiltration (SVI) detection they were 0.51 and 0.60 (p =0.0008), and 0.93 and 0.96 (p =0.0092). For PSMA PET versus mpMRI in lymph node metastasis (LNM) detection, sensitivities and specificities in the per-patient analysis were 0.68 and 0.46 (p <0.0001), and 0.91 and 0.90 (p =0.81), and in the per-lesion analysis they were 0.67 and 0.36 (p <0.0001), and 0.99 and 0.99 (p =0.18).

CONCLUSION

PSMA PET has higher diagnostic value than mpMRI in the detection of primary PCa. Regarding the primary staging, mpMRI has potential advantages in SVI detection, while PSMA PET has relative advantages in LNM detection.

CLINICAL RELEVANCE STATEMENT

The integration of prostate-specific membrane antigen (PSMA) PET into the diagnostic pathway may be helpful for improving the accuracy of prostate cancer detection. However, further studies are needed to address the cost implications and evaluate its utility in specific patient populations or clinical scenarios. Moreover, we recommend the combination of PSMA PET and mpMRI for cancer staging.

KEY POINTS

• Prostate-specific membrane antigen PET has higher sensitivity and specificity for primary tumor detection in prostate cancer compared to multiparametric MRI. • Prostate-specific membrane antigen PET also has significantly better sensitivity and specificity for lymph node metastases of prostate cancer compared to multiparametric MRI. • Multiparametric MRI has better accuracy for extracapsular extension and seminal vesicle infiltration compared to ate-specific membrane antigen PET.

A systematic review and meta-analysis to evaluate the diagnostic accuracy of PSMA PET/CT in the initial staging of prostate cancer

BACKGROUND

Positron Emission Tomography-Computed Tomography using Prostate-Specific Membrane Antigen (PSMA PET/CT) is notable for its superior sensitivity and specificity in detecting recurrent PCa and is under investigation for its potential in pre-treatment staging. Despite its established efficacy in nodal and metastasis staging in trial setting, its role in primary staging awaits fuller validation due to limited evidence on oncologic outcomes. This systematic review and meta-analysis aims to appraise the diagnostic accuracy of PSMA PET/CT compared to CI for comprehensive PCa staging.

METHODS

Medline, Scopus and Web of science databases were searched till March 2023. Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were followed to identify eligible studies. Primary outcomes were specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV) of PSMA PET/CT for local, nodal and metastatic staging in PCa patients. Due to the unavailability of data, a meta-analysis was feasible only for detection of seminal vesicles invasion (SVI) and LNI.

RESULTS

A total of 49 studies, comprising 3876 patients, were included. Of these, 6 investigated accuracy of PSMA PET/CT in detection of SVI. Pooled sensitivity, specificity, PPV and NPV were 42.29% (95%CI: 29.85-55.78%), 87.59% (95%CI: 77.10%-93.67%), 93.39% (95%CI: 74.95%-98.52%) and 86.60% (95%CI: 58.83%-96.69%), respectively. Heterogeneity analysis revealed significant variability for PPV and NPV. 18 studies investigated PSMA PET/CT accuracy in detection of LNI. Aggregate sensitivity, specificity, PPV and NPV were 43.63% (95%CI: 34.19-53.56%), 85.55% (95%CI: 75.95%-91.74%), 67.47% (95%CI: 52.42%-79.6%) and 83.61% (95%CI: 79.19%-87.24%). No significant heterogeneity was found between studies.

CONCLUSIONS

The present systematic review and meta-analysis highlights PSMA PET-CT effectiveness in detecting SVI and its good accuracy in LNI compared to CI. Nonetheless, it also reveals a lack of high-quality research on its performance in clinical T staging, extraprostatic extension and distant metastasis evaluation, emphasizing the need for further rigorous studies.

Correlation between pre-radical prostatectomy standardized SUVmax ratios detected on 68Ga-PSMA-I&T PET/CT and final histopathology outcomes: an in-depth analysis

OBJECTIVE

To evaluate the predictive potential of the maximum standardized uptake value(SUVmax) value of intraprostatic tumors derived from preoperative 68Ga-PSMA-I&T PET/CT (SUVT), and its ratios to SUVmax in the liver (SUVTLR) and parotid gland (SUVTPR) with respect to histopathological findings.

MATERIALS AND METHODS

Data from patients who underwent radical prostatectomy (RP) for prostate cancer (PC) at our clinic between 2017 and 2020 were assessed. Patients with a secondary malignancy, a history of transurethral prostate resection, prior treatment for PC, or who received salvage RP were excluded. Whole-body images obtained using the same device, as per the guidelines, were reviewed by two nuclear medicine specialists with more than a decade of experience to reach a consensus for each lesion. The relationships between age, PSA, Prostate Volume, clinical T stage, biopsy International Society of Urological Pathology grade (ISUP), D'amico risk group, intraprostatic tumor volume (HPTV) identified in the final histopathological specimen review, HP-ISUP grade, seminal vesicle invasion (SVI), extracapsular invasion (ECI), positive surgical margine (PSM), SUVT, SUVTLR, and SUVTPR were analyzed.

RESULTS

The mean age of the 64 included patients was 64.1 ± 5.3. A statistically significant correlation was found between SUVT, SUVTLR, SUVTPR values, and histopathologic stage parameters, such as biopsy ISUP, D'amico Risk Classification, HP-ISUP, HPTV (p < 0.05). PSMATV, SUVT, and SUVTLR were statistically significant predictors of extracapsular invasion, while PSA, PSMATV, and SUVTLR were significant predictors of SVI (p < 0.05).

CONCLUSION

The standardized SUVT, SUVTLR, and SUVTPR values could be employed as noninvasive markers to assist in predicting postoperative histopathological findings, particularly ECI, SVI, and PSM.

A comparison study of 68gallium-prostate-specific membrane antigen positron emission tomography-computed tomography and multiparametric magnetic resonance imaging for locoregional staging of prostate cancer

Purpose

Prostate cancer (PCa) is the most common malignancy in men aged 50 years and older and the second cause of cancer death among men. Accurate staging of PCa preoperatively is of high importance for treatment decisions and patient management. Conventional imaging modalities (ultrasound, computed tomography [CT], and magnetic resonance imaging) are inaccurate for the staging of PCa. Newer modality multiparametric magnetic resonance imaging (mpMRI) and prostate-specific membrane antigen (PSMA) positron emission tomography (PET) scan show promising results for the staging of PCa. Only fewer studies are available for comparison of these modalities with histopathology as reference. The objective of our study is to evaluate the diagnostic accuracy of independent 68gallium PSMA (68Ga-PSMA) PET-CT compared with mpMRI for preoperative staging of PCa, using histopathology as the reference standard.

Materials and methods

From August 2021 to December 2022, 30 patients of biopsy-proven PCa were prospectively enrolled as per eligibility criteria. Preoperatively, 68Ga-PSMA PET scan and mpMRI were done in all the patients. Extracapsular extension (ECE), seminal vesicle invasion (SVI), and lymph node metastasis (LNM) were investigated separately. Subsequently, the patients underwent robotic-assisted radical prostatectomy with bilateral pelvic lymph node dissection.

Results

mpMRI prostate was more sensitive (66.66%) but less specific than PSMA PET-CT (55.55%) for ECE. mpMRI and PSMA PET-CT both had similar sensitivity (83.3%) and specificity (87.5%) for SVI. PSMA PET-CT was more sensitive (85.71%) and specific (95.6%) than mpMRI prostate (62.5% and 91.30%, respectively) for LNM.

Conclusion

PSMA PET-CT is more specific for the detection of ECE and more sensitive and specific for the detection of LNM than mpMRI, and similar for the detection of SVI. mpMRI provides only local staging, while PSMA PET-CT provides information about local, regional, and distal staging. Overall, PSMA PET-CT is superior to mpMRI for locoregional staging of PCa.

The Impact of Positron Emission Tomography Imaging and Tumor Molecular Profiling on Risk Stratification, Treatment Choice, and Oncological Outcomes of Patients with Primary or Relapsed Prostate Cancer: An International Collaborative Review of the Existing Literature

CONTEXT

The clinical introduction of next-generation imaging methods and molecular biomarkers ("radiogenomics") has revolutionized the field of prostate cancer (PCa). While the clinical validity of these tests has thoroughly been vetted, their clinical utility remains a matter of investigation.

OBJECTIVE

To systematically review the evidence to date on the impact of positron emission tomography (PET) imaging and tissue-based prognostic biomarkers, including Decipher, Prolaris, and Oncotype Dx, on the risk stratification, treatment choice, and oncological outcomes of men with newly diagnosed PCa or those with biochemical failure (BCF).

EVIDENCE ACQUISITION

We performed a quantitative systematic review of the literature using the MEDLINE, EMBASE, and Web of Science databases (2010-2022) following the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement guidelines. The validated Quality Assessment of Diagnostic Accuracy Studies 2 scoring system was used to assess the risk of bias.

EVIDENCE SYNTHESIS

A total of 148 studies (130 on PET and 18 on biomarkers) were included. In the primary PCa setting, prostate-specific membrane antigen (PSMA) PET imaging was not useful in improving T staging, moderately useful in improving N staging, but consistently useful in improving M staging in patients with National Comprehensive Cancer Network (NCCN) unfavorable intermediate- to very-high-risk PCa. Its use led to a management change in 20-30% of patients. However, the effect of these treatment changes on survival outcomes was not clear. Similarly, biomarkers in the pretherapy primary PCa setting increased and decreased the risk, respectively, in 7-30% and 32-36% of NCCN low-risk and 31-65% and 4-15% of NCCN favorable intermediate-risk patients being considered for active surveillance. A change in management was noted in up to 65% of patients, with the change being in line with the molecular risk-based reclassification, but again, the impact of these changes on survival outcomes remained unclear. Notably, in the postsurgical primary PCa setting, biomarker-guided adjuvant radiation therapy (RT) was associated with improved oncological control: Δ↓ 2-yr BCF by 22% (level 2b). In the BCF setting, the data were more mature. PSMA PET was consistently useful in improving disease localization-Δ↑ detection for T, N, and M staging was 13-32%, 19-58%, and 9-29%, respectively. Between 29% and 73% of patients had a change in management. Most importantly, these management changes were associated with improved survival outcomes in three trials: Δ↑ 4-yr disease-free survival by 24.3%, Δ↑ 6-mo metastasis-free survival (MFS) by 46.7%, and Δ↑ androgen deprivation therapy-free survival by 8 mo in patients who received PET-concordant RT (level 1b-2b). Biomarker testing in these patients also appeared to be helpful in risk stratifying and guiding the use of early salvage RT (sRT) and concomitant hormonal therapy. Patients with high-genomic-risk scores benefitted from treatment intensification: Δ↑ 8-yr MFS by 20% with the use of early sRT and Δ↑ 12-yr MFS by 11.2% with the use of hormonal therapy alongside early sRT, while low-genomic-risk score patients did equally well with initial conservative management (level 3).

CONCLUSIONS

Both PSMA PET imaging and tumor molecular profiling provide actionable information in the management of men with primary PCa and those with BCF. Emerging data suggest that radiogenomics-guided treatments translate into direct survival benefits for patients, however, additional prospective data are awaited.

PATIENT SUMMARY

In this review, we evaluated the utility of prostate-specific membrane antigen positron emission tomography and tumor molecular profiling in guiding the care of men with prostate cancer (PCa). We found that these tests augmented risk stratification, altered management, and improved cancer control in men with a new diagnosis of PCa or for those experiencing a relapse.

Comparison of Multiparametric MRI, [68Ga]Ga-PSMA-11 PET-CT, and Clinical Nomograms for Primary T and N Staging of Intermediate-to-High-Risk Prostate Cancer

PURPOSE OF THE REPORT

Although multiparametric magnetic resonance imaging (mpMRI) is commonly used for the primary staging of prostate cancer, it may miss non-enlarged metastatic lymph nodes. Positron emission tomography-computed tomography targeting the prostate-specific membrane antigen (PSMA PET-CT) is a promising method to detect non-enlarged metastatic lymph nodes, but more data are needed.

MATERIALS AND METHODS

In this single-center, prospective study, we enrolled patients with intermediate-to-high-risk prostate cancer scheduled for radical prostatectomy with pelvic node dissection. Before surgery, prostate imaging with mpMRI and PSMA PET-CT was used to assess lymph node involvement (LNI), extra-prostatic extension (EPE), and seminal vesicle involvement (SVI). Additionally, we used clinical nomograms to estimate the risk of these three outcomes.

RESULTS

Of the 74 patients included, 61 (82%) had high-risk prostate cancer, and the rest had intermediate-risk cancer. Histopathology revealed LNI in 20 (27%) patients, SVI in 26 (35%), and EPE in 52 (70%). PSMA PET-CT performed better than mpMRI at detecting LNI (area under the curve (AUC, 95% confidence interval): 0.779 (0.665-0.893) vs. 0.655 (0.529-0.780)), but mpMRI was better at detecting SVI (AUC: 0.775 (0.672-0.878) vs. 0.585 (0.473-0.698)). The MSKCC nomogram performed well at detecting both LNI (AUC: 0.799 (0.680-0.918)) and SVI (0.772 (0.659-0.885)). However, when the nomogram was used to derive binary diagnoses, decision curve analyses showed that the MSKCC nomogram provided less net benefit than mpMRI and PSMA PET-CT for detecting SVI and LNI, respectively.

CONCLUSIONS

mpMRI and [68Ga]Ga-PSMA-11 PET-CT are complementary techniques to be used in conjunction for the primary T and N staging of prostate cancer.

The diagnostic accuracy of radiolabeled PSMA-ligand PET for tumour staging in newly diagnosed prostate cancer patients compared to histopathology: a systematic review and meta-analysis

PURPOSE

The current clinical recommendations posit the deployment of specific approved radiolabeled prostate-specific membrane antigen-ligand positron emission tomography (PSMA PET) for detecting metastatic prostate cancer during primary staging. Nevertheless, the precise efficacy of such ligands in localizing intraprostatic tumours (index tumour) and T-staging is not well established. Consequently, the objective of this inquiry is to ascertain the diagnostic accuracy of PSMA-PET in the tumour staging of newly diagnosed prostate cancer by means of a meta-analysis that integrates studies utilizing histological confirmation as the reference standard.

METHODS

In this study, we conducted a systematic literature search of the PubMed, Embase, Web of Science, and Cochrane Library databases using a predefined collection of search terms. These terms included 'PSMA PET', 'primary staging', and 'prostate cancer'. Subsequently, two independent reviewers evaluated all the studies based on predetermined inclusion criteria, extracted pertinent data, and assessed the quality of evidence. Any disparities were resolved by a third reviewer. A random effects Sidik-Jonkman model was applied to conduct a meta-analysis and estimate the diagnostic accuracy on a per-patient basis, along with 95% confidence intervals. Moreover, an appraisal regarding the likelihood of publication bias and the impact of small-study effects was performed utilizing both Egger's test and a graphical examination of the funnel plot.

RESULTS

The present analysis comprised a total of twenty-three scientific papers encompassing 969 patients and involved their analysis by both qualitative and quantitative approaches. The results of this study demonstrated that the estimated diagnostic accuracy of PSMA PET/CT and PSMA PET/MRI, for the detection of intraprostatic tumours, regardless of the type of PSMA-ligand, was 86% (95% CI: 76-96%) and 97% (95% CI: 94-100%), respectively. Furthermore, the diagnostic accuracy for the detection of extraprostatic extension (EPE) was 73% (95% CI: 64-82%) and 77% (95% CI: 69-85%), while the diagnostic accuracy for the detection of seminal vesicle involvement (SVI) was 87% (95% CI: 80-93) and 90% (95% CI: 82-99%), respectively.

CONCLUSION

The present investigation has demonstrated that PSMA PET/MRI surpasses currently recommended multiparametric magnetic resonance imaging (mpMRI) in terms of diagnostic accuracy as inferred from a notable data trajectory, whereas PSMA-PET/CT exhibited comparable diagnostic accuracy for intraprostatic tumour detection and T-staging compared to mpMRI. Nevertheless, the analysis has identified certain potential limitations, such as small-study effects and a potential for publication bias, which may impact the overall conclusions drawn from this study.

Head-to-head Comparison of the Diagnostic Accuracy of Prostate-specific Membrane Antigen Positron Emission Tomography and Conventional Imaging Modalities for Initial Staging of Intermediate- to High-risk Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

Whether prostate-specific membrane antigen positron emission tomography (PSMA-PET) should replace conventional imaging modalities (CIM) for initial staging of intermediate-high risk prostate cancer (PCa) requires definitive evidence on their relative diagnostic abilities.

OBJECTIVE

To perform head-to-head comparisons of PSMA-PET and CIM including multiparametric magnetic resonance imaging (mpMRI), computed tomography (CT) and bone scan (BS) for upfront staging of tumour, nodal, and bone metastasis.

EVIDENCE ACQUISITION

A search of the PubMed, EMBASE, CENTRAL, and Scopus databases was conducted from inception to December 2021. Only studies in which patients underwent both PSMA-PET and CIM and imaging was referenced against histopathology or composite reference standards were included. Quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) checklist and its extension for comparative reviews (QUADAS-C). Pairwise comparisons of the sensitivity and specificity of PSMA-PET versus CIM were performed by adding imaging modality as a covariate to bivariate mixed-effects meta-regression models. The likelihood ratio test was applied to determine whether statistically significant differences existed.

EVIDENCE SYNTHESIS

A total of 31 studies (2431 patients) were included. PSMA-PET/MRI was more sensitive than mpMRI for detection of extra-prostatic extension (78.7% versus 52.9%) and seminal vesicle invasion (66.7% versus 51.0%). For nodal staging, PSMA-PET was more sensitive and specific than mpMRI (73.7% versus 38.9%, 97.5% versus 82.6%) and CT (73.2% versus 38.5%, 97.8% versus 83.6%). For bone metastasis staging, PSMA-PET was more sensitive and specific than BS with or without single-photon emission computerised tomography (98.0% versus 73.0%, 96.2% versus 79.1%). A time interval between imaging modalities >1 month was identified as a source of heterogeneity across all nodal staging analyses.

CONCLUSIONS

Direct comparisons revealed that PSMA-PET significantly outperforms CIM, which suggests that PSMA-PET should be used as a first-line approach for the initial staging of PCa.

PATIENT SUMMARY

We reviewed direct comparisons of the ability of a scan method called PSMA-PET (prostate-specific membrane antigen positron emission tomography) and current imaging methods to detect the spread of prostate cancer outside the prostate gland. We found that PSMA-PET is more accurate for detection of the spread of prostate cancer to adjacent tissue, nearby lymph nodes, and bones.

Comparing the Detection Performance Between Multiparametric Magnetic Resonance Imaging and Prostate-Specific Membrane Antigen PET/CT in Patients With Localized Prostate Cancer: A Systematic Review and Meta-analysis

PURPOSE

Multiparametric MRI (mpMRI) has been promoted as an auxiliary diagnostic tool for prostate biopsy. However, prostate-specific membrane antigen (PSMA) including 68 Ga-PSMA-11, 18 F-DCFPyL, and 18 F-PSMA-1007 applied PET/CT imaging was an emerging diagnostic tool in prostate cancer patients for staging or posttreatment follow-up, even early detecting. Many studies have used PSMA PET for comparison with mpMRI to test the diagnostic ability for early prostate cancer. Unfortunately, these studies have shown conflicting results. This meta-analysis aimed to compare the differences in diagnostic performance between PSMA PET and mpMRI for detecting and T staging localized prostatic tumors.

METHODS

This meta-analysis involved a systematic literature search of PubMed/MEDLINE and Cochrane Library databases. The pooling sensitivity and specificity of PSMA and mpMRI verified by pathological analysis were calculated and used to compare the differences between the 2 imaging tools.

RESULTS

Overall, 39 studies were included (3630 patients in total) from 2016 to 2022 in the current meta-analysis and found that the pooling sensitivity values for localized prostatic tumors and T staging T3a and T3b of PSMA PET were 0.84 (95% confidence interval [CI], 0.83-0.86), 0.61 (95% CI, 0.39-0.79), and 0.62 (95% CI, 0.46-0.76), respectively, whereas those of mpMRI were found to be 0.84 (95% 0.78-0.89), 0.67 (95% CI, 0.52-0.80), and 0.60 (95% CI, 0.45-0.73), respectively, without significant differences ( P > 0.05). However, in a subgroup analysis of radiotracer, the pooling sensitivity of 18 F-DCFPyL PET was higher than mpMRI (relative risk, 1.10; 95% CI, 1.03-1.17; P < 0.01).

CONCLUSIONS

This meta-analysis found that whereas 18 F-DCFPyL PET was superior to mpMRI at detecting localized prostatic tumors, the detection performance of PSMA PET for localized prostatic tumors and T staging was comparable to that of mpMRI.

Preoperative evaluation of prostate cancer by 68Ga-PMSA positron emission tomography/computed tomography: comparison with magnetic resonance imaging and with histopathological findings

Objective

To evaluate the accuracy of preoperative positron emission tomography/computed tomography with 68Ga-labeled prostate-specific membrane antigen (68Ga-PSMA PET/CT) for staging prostate cancer and compare it with magnetic resonance imaging (MRI) using histopathology of surgical specimens as the gold standard.

Materials and Methods

In this retrospective study, 65 patients with prostate cancer were analyzed.

Results

The accuracy of 68Ga-PSMA PET/CT for tumor detection was 95%, and that of MRI was 91%. There was no difference between 68Ga-PSMA PET/CT and MRI regarding localization of the lesion. The sensitivity of 68Ga-PSMA PET/CT for detecting extraprostatic extension was quite low (14%). For detection of seminal vesicle invasion, 68Ga-PSMA PET/CT showed a sensitivity of 57% and accuracy of 91%. There was a moderate correlation between the maximum standardized uptake value (SUVmax) and the serum level of prostate-specific antigen (p < 0.01; ρ = 0.368) and between the SUVmax and the International Society of Urological Pathology (ISUP) grade (p < 0.01; ρ = 0.513).

Conclusion

68Ga-PSMA PET/CT is a promising tool for detecting and evaluating the primary tumor, which can alter the staging and management of the disease.

Ability of 68 Ga‐PSMA PET / CT SUVmax to differentiate ISUP GG2 from GG3 in intermediate‐risk prostate cancer: A single‐center retrospective study of 147 patients

OBJECTIVE

To evaluate the ability of ⁶⁸ Ga-PSMA PET/CT maximum standard uptake value (SUVmax) to distinguish prostate cancer (PCa) International Society of Urological Pathology ISUP grade group (GG) 2 and GG3.

METHODS

The PET/CT images and data of 147 patients were analyzed retrospectively, and the SUVmax of the index lesions were measured. The receiver operating characteristic curve was used to analyze the diagnostic value of PET/CT for PCa. The correlation between SUVmax and ISUP GG was analyzed. A logistic regression model was established with SUVmax and was validated to predict its value of diagnosing intermediate- and high-risk PCa (ihPCa).

RESULTS

Of the 147 patients, 112 cases were PCa (76.2%), and 35 cases were benign lesions (23.8%). There was a significant difference between the benign and the malignant groups (p < 0.05). The median SUVmax of ihPCa was significantly higher than that of the benign and low-risk groups (p < 0.05). The median SUVmax of GG3 was significantly higher than that of the GG2 group (p < 0.05). There were no statistically significant SUVmax differences among GG3, GG4, and GG5 groups (p > 0.05). The specificity and the positive predictive value of ⁶⁸ Ga-PSMA PET/CT in the diagnosis of PCa were 97% and 99% with cut-off SUVmax of 6.94, while the specificity and the positive predictive value of ihPCa were 95% and 96% with cut-off SUVmax of 10.12.

CONCLUSION

⁶⁸ Ga-PSMA PET/CT can reliably distinguish GG2 from GG3 PCa.

Comparison of 68Ga-PSMA PET/CT and mp-MRI in regard to local staging for prostate cancer with histopathological results: A retrospective study

BACKGROUND

Imaging modalities are used to diagnose and clinical grading of clinically significant prostate cancer. In this study, 68Ga-PSMA PET/CT (PSMA) and multiparametric prostate MRI (mp-MRI) were compared in regard to locating intraprostatic tumor and locoregional staging.

METHODS

After ethics committee approval, a total of 49 patients with prostate cancer who had mp-MRI and PSMA before radical prostatectomy were included. Preoperative and postoperative PSA, transrectal ultrasound-guided prostate biopsy (TRUS-Bx) ISUP grade, radical prostatectomy ISUP grade, body mass index (BMI), TRUS prostate volume, mp-MRI tumor mapping, PSMAtumor mapping, pathologic tumor mapping, extraprostatic extension (EPE), seminal vesicle invasion (SVI), lymph node invasion (LNI), and bladder neck invasion (BNI)were retrospectively evaluated. Index tumor was located by uroradiologist, nuclear medicine specialist, and uropathologist on a 12-sector prostate pathology map and compared with each other in terms of accuracy and locoregional clinical staging.

RESULTS

Mean age of the patients was 66.18 ± 6.67 years and the mean of preoperative PSA results was 21.11 ± 32.56 ng/ml. Nearly half of the patients' (44.9%) pathology was reported as ISUP grade 4 and 5% and 18.4% of patients were surgical margin positive. According to the pathological findings, 362 out of 588 sectors were tumor-positive, 174 out of 362 sectors were tumor-positive in mp-MRI, and 175 out of 362 sectors were tumor-positive in PSMA. Both PSMA and mp-MRI were comparable (p = 0.823) and accurate to detect the location of the intraprostatic index tumor (AUC = 0.66 vs. 0.69 respectively, p = 0.82). The sensitivity and the specificity of the PSMA and mp-MRI for localizing intraprostatic index tumors were 42.5% versus 49.5% and 90.7% versus 88.6% respectively. mp-MRI was more accurate than PSMA in terms of EPE (AUC = 0.8 vs. AUC = 0.57 respectively, p = 0.027) and both methods were comparable in terms of SVI (AUC = 0.75 vs. AUC = 0.75, p = 0.886) and BNI (AUC = 0.51 vs. AUC = 0.59, p = 0.597). PSMA and mp-MRI were comparable in terms of LNI (AUC = 0.76 vs. AUC = 0.64, p = 0.39).

CONCLUSION

mp-MRI should be considered for its high accuracy in the diagnosis of EPE, especially before decision-making for nerve-sparing surgery in high-risk patients. Both imaging modalities were accurate for localizing intraprostatic index tumor. PSMA is accurate for detecting LNI.

Prostate specific membrane antigen positron emission tomography in primary prostate cancer diagnosis: First-line imaging is afoot

Prostate specific membrane antigen positron emission tomography (PSMA PET) is an excellent molecular imaging technique for prostate cancer. Currently, PSMA PET for patients with primary prostate cancer is supplementary to conventional imaging techniques, according to guidelines. This supplementary function of PSMA PET is due to a lack of systematic review of its strengths, limitations, and potential development direction. Thus, we review PSMA ligands, detection, T, N, and M staging, treatment management, and false results of PSMA PET in clinical studies. We also discuss the strengths and challenges of PSMA PET. PSMA PET can greatly increase the detection rate of prostate cancer and accuracy of T/N/M staging, which facilitates more appropriate treatment for primary prostate cancer. Lastly, we propose that PSMA PET could become the first-line imaging modality for primary prostate cancer, and we describe its potential expanded application.

The Diagnostic Value of High-Resolution Computed Tomography Features Combined with Mycoplasma Pneumoniae Ribonucleic Acid Load Detection for Refractory Mycoplasma Pneumonia

The aim of this study was to investigate the value of high-resolution computed tomography (CT) images and mycoplasma pneumoniae (MP) ribonucleic acid (RNA) load detection in the early diagnosis of refractory mycoplasma pneumoniae (RMP) and provide more methods for the diagnosis and treatment of RMP. Seventy children with MP were divided into the RMP group (H1 group, 31 cases) and the MP group (H2 group, 39 cases) according to pathological findings, and all of them underwent CT scanning. MP-RNA load and genotype distribution were analyzed in both groups, and the diagnostic efficacy of CT combined with MP-RNA load for RMP was calculated. The sensitivity of children in the H1 group to erythromycin (59.17% vs 71.56%) and clarithromycin (53.21% vs 67.03%) was lower than that in the H2 group, and the resistance rate of children in the H1 group to erythromycin (71.43% vs 67.53%) and clarithromycin (64.24% vs 50.37%) was higher than that in the H2 group (P < 0.05); the regression coefficients between lactate dehydrogenase (LDH) and the MPLI value of RMP were −0.064 and −0.413, respectively, which were significantly negatively correlated (P < 0.05); the accuracy (96.5%), sensitivity (92.5%), and specificity (88%) of CT + MP-RNA in the diagnosis of RMP were significantly higher than those of CT alone (91%, 88%, and 82%) and MP-RNA alone (88%, 84.5%, and 74%), which were significantly different (P < 0.05). The results of high MP-RNA load detection can be used as an indicator to predict RMP, and the diagnostic efficacy is significantly improved after combination with high-resolution CT, with high clinical application value.

Quantitative imaging parameters to predict the local staging of prostate cancer in intermediate- to high-risk patients

Objectives

PSMA PET/MRI showed the potential to increase the sensitivity for extraprostatic disease (EPD) assessment over mpMRI; however, the interreader variability for EPD is still high. Therefore, we aimed to assess whether quantitative PSMA and mpMRI imaging parameters could yield a more robust EPD prediction.

Methods

We retrospectively evaluated PCa patients who underwent staging mpMRI and [68Ga]PSMA-PET, followed by radical prostatectomy at our institution between 01.02.2016 and 31.07.2019. Fifty-eight cases with PET/MRI and 15 cases with PET/CT were identified. EPD was determined on histopathology and correlated with quantitative PSMA and mpMRI parameters assessed by two readers: ADC (mm2/1000 s), longest capsular contact (LCC, mm), tumor volume (cm3), PSMA-SUVmax and volume-based parameters using a fixed threshold at SUV > 4 to delineate PSMAtotal (g/ml) and PSMAvol (cm3). The t test was used to compare means, Pearson’s test for categorical correlation, and ROC curve to determine the best cutoff. Interclass correlation (ICC) was performed for interreader agreement (95% CI).

Results

Seventy-three patients were included (64.5 ± 6.0 years; PSA 14.4 ± 17.1 ng/ml), and 31 had EPD (42.5%). From mpMRI, only LCC reached significance (p = 0.005), while both volume-based PET parameters PSMAtotal and PSMAvol were significantly associated with EPD (p = 0.008 and p = 0.004, respectively). On ROC analysis, LCC, PSMAtotal, and PSMAvol reached an AUC of 0.712 (p = 0.002), 0.709 (p = 0.002), and 0.718 (p = 0.002), respectively. ICC was moderate–good for LCC 0.727 (0.565–0.828) and excellent for PSMAtotal and PSMAvol with 0.944 (0.990–0.996) and 0.985 (0.976–0.991), respectively.

Conclusions

Quantitative PSMA parameters have a similar potential as mpMRI LCC to predict EPD of PCa, with a significantly higher interreader agreement.

Efficacy of 68Ga-PSMA-11 PET/CT with biparametric MRI in diagnosing prostate cancer and predicting risk stratification: a comparative study

BACKGROUND

This retrospective study aimed to investigate the efficacy of the combined application of biparametric magnetic resonance imaging (bpMRI) and ⁶⁸Ga-PSMA-11 positron emission computed tomography/computed tomography (bpMRI/PET) in the qualitative diagnosis of intermediate- to high-risk prostate cancer (PCa).

METHODS

The 105 patients with suspected PCa included in the study underwent bpMRI and PET/CT. BpMRI examinations included conventional sequences and diffusion-weighted imaging (DWI) sequences. Major lesions were qualitatively diagnosed according to the Prostate Imaging Reporting and Data System (PI-RADS). A PET/CT scan was started 60 min after intravenous ⁶⁸Ga-PSMA-11 injection. The area with the highest radioactivity on PET/CT images was defined as the major lesion, and the maximum standard uptake value (SUV_max) was measured. All cases were confirmed by biopsy and pathology. Receiver operating characteristic curve (ROC) analysis was performed on the data to calculate sensitivity, specificity, and the Youden index.

RESULTS

Of the 105 patients, 68 patients were diagnosed with PCa, and 37 patients had benign prostatic lesions. With a PI-RADS score ≥3 as the diagnostic threshold, the accuracy of bpMRI in identifying benign and malignant prostate lesions was similar to that of PET/CT (SUV_max threshold ≥10.9), and the Youden indices were 0.60 and 0.64, respectively. The sensitivity and specificity of bpMRI in the differential diagnosis of intermediate- to high-risk PCa versus low-risk PCa or benign lesions were 63% and 88%, respectively, and the Youden index was 0.51. With an SUV_max ≥12.9 as the diagnostic threshold, the sensitivity and specificity of PET/CT in the differential diagnosis of intermediate- to high-risk PCa versus low-risk PCa or benign lesions were 74% and 94%, respectively, and the Youden index was 0.68. The sensitivity and specificity of bpMRI/PET in diagnosing PCa were 94% and 81%, respectively, and the Youden index was 0.75. The sensitivity and specificity of bpMRI/PET in the differential diagnosis of intermediate- to high-risk PCa versus low-risk PCa or benign lesions were 80% and 88%, respectively, and the Youden index was 0.68.

CONCLUSIONS

The combined application of bpMRI and PET improves the accuracy of the qualitative diagnosis of prostate lesions, and its diagnostic efficacy for risk stratification in patients with intermediate- to high-risk PCa is similar to that of PET/CT and higher than that of bpMRI alone.

Preliminary Results of an Ongoing Prospective Clinical Trial on the Use of 68Ga-PSMA and 68Ga-DOTA-RM2 PET/MRI in Staging of High-Risk Prostate Cancer Patients

The aim of the present study is to investigate the synergic role of ⁶⁸Ga-PSMA PET/MRI and ⁶⁸Ga-DOTA-RM2 PET/MRI in prostate cancer (PCa) staging. We present pilot data on twenty-two patients with biopsy-proven PCa that underwent ⁶⁸Ga-PSMA PET/MRI for staging purposes, with 19/22 also undergoing ⁶⁸Gaa-DOTA-RM2 PET/MRI. TNM classification based on image findings was performed and quantitative imaging parameters were collected for each scan. Furthermore, twelve patients underwent radical prostatectomy with the availability of histological data that were used as the gold standard to validate intraprostatic findings. A DICE score between regions of interest manually segmented on the primary tumour on ⁶⁸Ga-PSMA PET, ⁶⁸Ga-DOTA-RM2 PET and on T2 MRI was computed. All imaging modalities detected the primary PCa in 18/19 patients, with ⁶⁸Ga-DOTA-RM2 PET not detecting any lesion in 1/19 patients. In the remaining patients, ⁶⁸Ga-PSMA and MRI were concordant. Seven patients presented seminal vesicles involvement on MRI, with two of these being also detected by ⁶⁸Ga-PSMA, and ⁶⁸Ga-DOTA-RM2 PET being negative. Regarding extraprostatic disease, ⁶⁸Ga-PSMA PET, ⁶⁸Ga-DOTA-RM2 PET and MRI resulted positive in seven, four and five patients at lymph-nodal level, respectively, and at a bone level in three, zero and one patients, respectively. These preliminary results suggest the potential complementary role of ⁶⁸Ga-PSMA PET, ⁶⁸Ga-DOTA-RM2 PET and MRI in PCa characterization during the staging phase.

Head-to-Head Comparison of 68Ga-PSMA-11 PET/CT and Multiparametric MRI for Pelvic Lymph Node Staging Prior to Radical Prostatectomy in Patients With Intermediate to High-Risk Prostate Cancer: A Meta-Analysis

PURPOSE

To compare the diagnostic performance of 68Ga-PSMA-11 PET/CT and mpMRI for pelvic lymph node staging prior to radical prostatectomy in prostate cancer (PCa) patients based on per patient data.

METHODS

PubMed and Embase databases were searched until October 2020 for eligible studies evaluating head-to-head comparison of 68Ga-PSMA-PET/CT and mpMRI for the detection of pelvic lymph node metastases (PLNMs) using pelvic lymph node dissection (PLND) as gold standard. The pooled sensitivity, specificity, and area under the summary receiver-operating characteristics curve (AUC) were determined for the two imaging modalities.

RESULTS

Nine studies with 640 patients were included. The pooled sensitivity, specificity, and AUC for 68Ga-PSMA-11 PET/CT vs. mpMRI were 0.71 (95% CI: 0.48-0.86) vs. 0.40 (95% CI: 0.16-0.71), 0.92 (95% CI: 0.88-0.95) vs. 0.92 (95% CI: 0.80-0.97), and 0.92 (95% CI: 0.88-0.95) vs. 0.82 (95% CI: 0.79-0.86), respectively. There was substantial heterogeneity for both imaging modalities, and meta-regression analysis revealed that the number of patients, prevalence of PLNMs, PSA level, reference standard, and risk classification might be the potential causes of heterogeneity.

CONCLUSION

This meta-analysis of head-to-head comparison studies confirms that there is a trend toward a higher sensitivity and diagnostic accuracy of 68Ga-PSMA-11 PET/CT compared to mpMRI for the detection of PLNMs in PCa patients. Nevertheless, according to current guidelines, PLND still needs to be recommended in case of negative results from 68Ga-PSMA-11 PET/CT due to significant risk of malignancy.

68Ga-PSMA PET/CT and mpMRI for primary lymph node staging of intermediate to high-risk prostate cancer: a systematic review and meta-analysis of diagnostic test accuracy

Purpose

To evaluate the diagnostic accuracy of Gallium-68 prostate-specific membrane antigen positron emission tomography-computed tomography (68Ga-PSMA PET/CT) compared with multiparametric magnetic resonance imaging (mpMRI) for detection of metastatic lymph nodes in intermediate to high-risk prostate cancer (PCa).

Methods

PRISMA-compliant systematic review updated to September 2020 was performed to identify studies that evaluated the diagnostic performance of 68Ga-PSMA PET/CT and mpMRI for detection of metastatic lymph nodes in the same cohort of PCa patients using histopathologic examination as a reference standard. The quality of each study was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) instrument. STATA version 16.0 was used to obtain the pooled estimates of diagnostic accuracy for per-patient and per-lesion analyses. Heterogeneity in the accuracy estimates was explored by reviewing the generated forest plots, summary receiver operator characteristic (SROC) curves, hierarchical SROC plots, chi-squared test, heterogeneity index, and Spearman’s correlation coefficients.

Results

Six studies, which included 476 patients, met the eligibility criteria for per-patient analysis and four of these studies, reporting data from 4859 dissected lymph nodes, were included in the per-lesion analysis. In the per-patient analysis (N = 6), the pooled sensitivity and specificity for 68Ga-PSMA PET/CT were 0.69 and 0.93, and for mpMRI the pooled sensitivity and specificity were 0.37 and 0.95. In the per-lesion analysis (N = 4), the pooled sensitivity and specificity for 68Ga-PSMA PET/CT were 0.58 and 0.99, and for mpMRI the pooled sensitivity and specificity were 0.44 and 0.99. There was high heterogeneity and a threshold effect in outcomes. A sensitivity analysis demonstrated that the pooled estimates were stable when excluding studies with patient selection concerns, whereas the variances of the pooled estimates became significant, and the characteristics of heterogeneity changed when excluding studies with concerns about index imaging tests.

Conclusion

Both imaging techniques have high specificity for the detection of nodal metastases of PCa. 68Ga-PSMA PET/CT has the advantage of being more sensitive and making it possible to detect distant metastases during the same examination. These modalities may play a complementary role in the diagnosis of PCa. Given the paucity of data and methodological limitations of the included studies, large scale trials are necessary to confirm their clinical values.

Prostate-Specific Membrane Antigen PET for Assessment of Primary and Recurrent Prostate Cancer with Histopathology as Reference Standard: A Systematic Review and Meta-Analysis

Prostate-specific membrane antigen PET is a promising diagnostic tool in prostate cancer. The gold standard for the detection of prostate tumor and lymph node metastases is histopathology. The aim of the present review was to investigate accuracy measures of ⁶⁸Ga/¹⁸F-labeled prostate-specific membrane antigen PET tracers in primary and recurrent prostate cancer with systematic sector-based histopathology as the reference standard. A systematic literature search was performed and 34 studies were included. Overall, prostate-specific membrane antigen PET showed high specificity, but variable sensitivity to localize known prostate cancer and detect pelvic lymph node metastases.

68Ga-PSMA-11 Positron Emission Tomography/Computed Tomography for Primary Lymph Node Staging Before Radical Prostatectomy: Central Review of Imaging and Comparison with Histopathology of Extended Lymphadenectomy

BACKGROUND

Results from prospective trials have shown higher accuracy of prostate-specific membrane antigen (PSMA)-based positron emission tomography (PET)/computed tomography (CT) in detection of lymph node metastasis (LNM) compared to conventional imaging.

OBJECTIVE

To evaluate the accuracy of ⁶⁸Ga-PSMA-11 PET/CT for LNM detection in patients undergoing radical prostatectomy (RP) and extended pelvic lymph node dissection (PLND).

DESIGN, SETTING, AND PARTICIPANTS

Between June 2014 and November 2020, 96 patients with ⁶⁸Ga-PSMA PET/CT for primary staging underwent RP and extended PLND.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The results from ⁶⁸Ga-PSMA PET/CT were compared with histologic data from primary PLND in 96 patients. All ⁶⁸Ga-PSMA PET/CT scans were centrally reviewed.

RESULTS AND LIMITATIONS

Of 96 patients, 15.6% (n = 15) harbored LNMs. The median prostate-specific antigen at ⁶⁸Ga-PSMA PET/CT was 8.0 ng/ml (interquartile range 5.5-11.7). The majority of patients had intermediate- (52.1%) or high-risk disease (41.7%). Biopsy grade group 4 and 5 was present in 22.9% and 15.6%, respectively. The ⁶⁸Ga-PSMA PET/CT scans identified eight of 15 patients (53.3%) as LN-positive (true positive). The calculated per-patient sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ⁶⁸Ga-PSMA PET/CT in the detection of LNM were 53.3%, 98.8%, 88.9%, 92.0%, and 91.7%, respectively. The per-patient sensitivity and specificity in the detection of LNMs larger than 2 mm were 61.5% and 98.8%, respectively. The main limitation is the retrospective design of the study.

CONCLUSIONS

⁶⁸Ga-PSMA PET/CT is accurate in lymph node staging and the results support its use for primary staging of prostate cancer.

PATIENT SUMMARY

We compared prostate-specific membrane antigen (PSMA)-based positron emission tomography (PET)/computed tomography (CT) findings with histopathology results after extended lymph node dissection and showed that it is accurate in detecting lymph node metastases. Our results support the use of PSMA PET/CT for primary staging of prostate cancer.

Can 68Ga-prostate specific membrane antigen positron emission tomography/computerized tomography provide an accurate lymph node staging for patients with medium/high risk prostate cancer? A diagnostic meta-analysis

Objective

This article aims to evaluate the diagnostic value of ⁶⁸Gallium-PSMA positron emission tomography/computerized tomography (⁶⁸Ga-PSMA PET/CT) for lymph node (LN) staging in patients with prostate cancer (PCa) by a meta-analysis of diagnostic tests.

Methods

We systematically retrieved articles from Web of Science, EMBASE, Cochrane Database, PubMed. The time limit is from the creation of the database until June 2019, and Stata 15 was used for calculation and statistical analyses.

Results

Sensitivity, specificity, positive and negative likelihood ratio (PLR, NLR), diagnostic odds ratio (DOR) and 95% confidence intervals (CI) be used to evaluate the diagnostic value. A total of 10 studies were included in our meta-analysis, which included 701 individuals. The results of each consolidated summary are as follows: sensitivity of 0.84 (95% CI 0.55–0.95), specificity of 0.95 (95% CI 0.87–0.98), PLR and NLR was 17.19 (95% CI 6.27, 47.17) and 0.17 (95% CI 0.05–0.56), respectively. DOR of 100 (95% CI 18–545), AUC of 0.97 (95% CI 0.95–0.98).

Conclusion

Our study demonstrates that ⁶⁸Ga-PSMA PET/CT has a high overall diagnostic value for LN staging in patients with moderate and high-risk PCa. But our conclusions still require a larger sample size, multi-center prospective randomized controlled trial to verify.

Prostate-specific membrane antigen positron emission tomography (PSMA-PET) for local staging of prostate cancer: a systematic review and meta-analysis

Purpose

Prostate-specific membrane antigen positron emission tomography (PSMA-PET) has shown promise for detecting nodal and distant prostate cancer (PCa) metastases. However, its performance for local tumor staging is not as well established. The purpose of this study was to review the diagnostic performance of PSMA-PET for determining seminal vesical invasion (SVI) and extraprostatic extension (EPE).

Methods

Pubmed and Embase databases were searched until January 12, 2020. Studies assessing accuracy of PSMA-PET in determining SVI and EPE were included. Study quality was evaluated with the revised Quality Assessment of Diagnostic Accuracy Studies-2 tool. Pooled sensitivity and specificity were calculated using hierarchical summary receiver operating characteristics modeling. Heterogeneity was explored using meta-regression analyses for anatomical imaging component (MRI vs CT) and by testing for a threshold effect.

Results

Twelve studies (615 patients) were included. Pooled sensitivity and specificity were 0.68 (95% CI 0.53-0.81) and 0.94 (95% CI 0.90-0.96) for SVI and 0.72 (95% CI 0.56-0.84) and 0.87 (95% CI 0.72-0.94) for EPE. Meta-regression analyses showed that for SVI, PET/MRI demonstrated greater sensitivity than PET/CT (0.87 [95% CI 0.75-0.98] vs 0.60 [95% CI 0.47-0.74]; p = 0.02 for joint model) while specificity was comparable (0.91 [95% CI 0.84-0.97] vs. 0.96 [95% CI 0.93-0.99]) but not for EPE (p = 0.08). A threshold effect was present for studies assessing EPE (correlation coefficient = 0.563 [95% CI, −0.234-0.908] between sensitivity and false-positive rate).

Conclusion

PSMA-PET has moderate sensitivity and excellent specificity for assessing local tumor extent in patients with PCa. PET/MRI showed potential for greater sensitivity than PET/CT in assessing SVI.

Prostate Cancer: Prostate-specific Membrane Antigen Positron-emission Tomography/Computed Tomography or Positron-emission Tomography/Magnetic Resonance Imaging for Staging

Positron-emission tomography (PET) with prostate-specific membrane antigen (PSMA) has been increasingly used to image prostate cancer in the last decade. In the staging setting several studies have already been published suggesting PSMA PET can be a valuable tool. They, however, did not translate into recommendations by guidelines. Both PSMA PET/computed tomography (CT) and PET/magnetic resonance imaging have been investigated in the staging setting, showing higher detection rate of prostate cancer lesions over the conventional imaging work-up and some studies already showed an impact on disease management. The aim of this review is to provide an overview of the existing published data regarding PSMA PET for staging prostate cancer, with emphasis on PET/magnetic resonance imaging. Despite the fact that PSMA is a relatively new tool and not officially recommended for staging yet, there are >50 original studies in the literature assessing PSMA PET performance in the staging setting of prostate cancer, and some meta-analyses.

Comparison of 68Ga-PSMA-I/T PET-CT and Multiparametric MRI for Locoregional Staging of Prostate Cancer Patients: A Pilot Study

BACKGROUND/AIM

The objective of this work was to assess the value of 68Ga-DOTAGA-(3-iodo-y)fk(Sub-KuE) positron emission tomography (68Ga-PSMA-I/T PET-CT) and multiparametric magnetic resonance imaging (mp-MRI) for preoperative staging in prostate cancer (PCa) patients who underwent radical prostatectomy (RP) by validating with postoperative histopathology data.

MATERIALS AND METHODS

We prospectively investigated 30 consecutive PCa patients who had both mp-MRI and 68Ga-PSMA-I/T PET-CT before laparoscopic RP. The seminal vesicle invasion (SVI), lymph node metastasis (LNM), bladder neck invasion (BNI), and extracapsular extension (ECE) were investigated separately. The diagnostic performances of mp-MRI and 68Ga-PSMA-I/T PET-CT were assessed using histopathological results.

RESULTS

Both mp-MRI and 68Ga-PSMA-I/T PET-CT were not statistically significant in the evaluation of SVI, BNI, and ECE preoperatively but had statistically significant results in the assessment of LNM. mp-MRI had higher overall sensitivity for ECE, overall specificity for SVI, ECE, and BNI, and positive predictive value for ECE, SVI, BNI. 68Ga-PSMA-I/T PET-CT had higher overall sensitivity for BNI, and negative predictive value for BNI and LNM.

CONCLUSION

mp-MRI has superior specificity, sensitivity, and accuracy for assessing ECE and SVI. Both imaging modalities had similar specificity, sensitivity, and accuracy for determining BNI. However, both imaging modalities had low diagnostic accuracy for LNM on histopathology.

Prostate specific membrane antigen positron emission tomography/computed tomography and staging high risk prostate cancer: a non-systematic review of high clinical impact literature

INTRODUCTION

Prostate specific membrane antigen (PSMA) positron emission tomography (PET) with computed tomography (CT) is a promising molecular imaging technique for prostate cancer (PCa). Although not yet included in international guidelines, PSMA PET/CT is commonly used in clinical practice to stage patients with newly diagnosed PCa. This review focuses on the most up-to-date literature on staging high-risk prostate cancer with PSMA PET/CT.

EVIDENCE ACQUISITION

An online based literature research encompassing original studies, reviews and meta-analysis was performed in the month of November of 2019. The most relevant and impactful research was then extracted based on the expertise of the authors, with the specific focus of highlighting the clinical impact and appropriateness of PSMA PET/CT in staging PCa.

EVIDENCE SYNTHESIS

The use of PSMA PET/CT is appropriate in all high-risk patients with newly diagnosed PCa as it will often have a significant clinical impact. Although preliminary findings are promising, there is still a scarcity of data regarding the performance of PSMA PET/CT vs. other modalities in defining disease within the prostate gland. There is good evidence suggesting that PSMA PET/CT may be superior to every other imaging modality in assessing loco-regional and distant metastatic disease.

CONCLUSIONS

PSMA PET/CT has the potential to become a gold standard in staging high risk prostate cancer, providing clinicians with accurate information on the extent of disease within the prostate and the presence of loco-regional and distant metastatic disease within a single scan.

PSMA PET for primary lymph node staging of intermediate and high-risk prostate cancer: an expedited systematic review

Background

PSMA PET is a promising method for primary lymph node staging in prostate cancer. However, recent systematic reviews have identified only a limited number of studies with histopathology as a reference test.

Methods

A systematic search was performed in PubMed and the Cochrane Library. An expedited systematic review was performed where we identified diagnostic studies in prostate cancer where a preoperative PSMA PET for primary lymph node staging was compared to histopathology. The trials must have diagnostic data on a patient level.

Results

Eighteen eligible clinical trials included 969 patients. The median patient number per study was 32 (range 10 to 208). Five trials were prospective, and nine trials had a consecutive enrolment of patients. Sixteen studies used Ga-68-PSMA-11; there was one study with Cu-64-PSMA and one study with F-18-DCDFPyL. Twelve studies used PET/CT, four trials used PET/MR. Most trials included patients with intermediate and high-risk. Diagnostic accuracy varied notably among the studies; sensitivity ranged from 23 to 100%, specificity 67–100%, positive predictive value 20–100%, and negative predictive value 41–100%. Weighted sensitivity was 59%, weighted specificity was 93%. Four studies compared PSMA PET with anatomical imaging (CT or MRI); in all cases, sensitivity and specificity were superior with PSMA PET. Three studies compared PSMA PET with multi-parametric or diffusion-weighted MRI with mixed results.

Conclusions

PSMA PET showed promising diagnostic accuracy for primary lymph node staging with pathology as reference. Recommendation for PSMA PET for high-risk patients in clinical guidelines should be supported by confirmatory, prospective trials with patient-relevant outcomes.

Use of gallium-68 prostate-specific membrane antigen positron-emission tomography for detecting lymph node metastases in primary and recurrent prostate cancer and location of recurrence after radical prostatectomy: an overview of the current literature

Objectives

To review the literature to determine the sensitivity and specificity of gallium‐68 prostate‐specific membrane antigen (⁶⁸Ga‐PSMA) positron‐emission tomography (PET) for detecting pelvic lymph node metastases in patients with primary prostate cancer (PCa), and the positive predictive value in patients with biochemical recurrence (BCR) after initial curative treatment, and, in addition, to determine the detection rate and management impact of ⁶⁸Ga‐PSMA PET in patients with BCR after radical prostatectomy (RP).

Materials and Methods

We performed a comprehensive literature search. Search terms used in MEDLINE, EMBASE and Science Direct were ‘(PSMA, ⁶⁸Ga‐PSMA, ⁶⁸Gallium‐PSMA, Ga‐68‐PSMA or prostate‐specific membrane antigen)’ and ‘(histology, lymph node, staging, sensitivity, specificity, positive predictive value, recurrence, recurrent or detection)’. Relevant abstracts were reviewed and full‐text articles obtained where possible. References to and from obtained articles were searched to identify further relevant articles.

Results

Nine retrospective and two prospective studies described the sensitivity and specificity of ⁶⁸Ga‐PSMA PET for detecting pelvic lymph node metastases before initial treatment, which ranged from 33.3% to 100% and 80% to 100%, respectively. In eight retrospective studies, the positive predictive value of ⁶⁸Ga‐PSMA PET in patients with BCR before salvage lymph node dissection ranged from 70% to 100%. The detection rate of ⁶⁸Ga‐PSMA PET in patients with BCR after RP in the PSA subgroups <0.2 ng/mL, 0.2–0.49 ng/mL and 0.5 to <1.0 ng/mL ranged from 11.3% to 50.0%, 20.0% to 72.7% and 25.0% to 87.5%, respectively.

Conclusion

The review results showed that ⁶⁸Ga‐PSMA PET had a high specificity for the detection of pelvic lymph node metastases in primary PCa. Furthermore, ⁶⁸Ga‐PSMA PET had a very high positive predictive value in detecting lymph node metastases in patients with BCR. By contrast, sensitivity was only moderate; therefore, based on the currently available literature, ⁶⁸Ga‐PSMA PET cannot yet replace pelvic lymph node dissection to exclude lymph node metastases. In the salvage phase, ⁶⁸Ga‐PSMA PET had both a high detection rate and impact on radiotherapy planning in early BCR after RP.