The Role of [68Ga]PSMA PET/CT for Clinical Suspicion of Prostate Cancer in Patients with or without Previous Negative Biopsy: A Systematic Review

Simple Summary

In this paper we systematically evaluate the evidence regarding the role of [⁶⁸Ga]PSMA PET/CT for clinical suspicions of prostate cancer in patients with or without previous negative biopsy. A critical review of PubMed and Web of Science according to the PRISMA statement was conducted. Eighteen publications were selected for inclusion in the analysis. In 8 articles, there was a direct comparison with mpMRI. [⁶⁸Ga]PSMA PET/CT resulted more accurate in identifying primary prostate cancer with PSA values between 4 and 20 ng/mL than mpMRI. Moreover, its use combined with MRI improved sensitivity for csPCa detection, thus potentially avoiding unnecessary biopsies. Overall, [⁶⁸Ga]PSMA PET/CT resulted a promising technique in patients with clinical suspicion of PCa and precedent negative biopsy or contraindications to MRI.

Abstract

The purpose of the study is to systematically evaluate the evidence regarding the role of [⁶⁸Ga]PSMA PET/CT for clinical suspicions of prostate cancer in patients with or without previous negative biopsy. We performed a critical review of PubMed and Web of Science according to the PRISMA statement. Eighteen publications were selected for inclusion in this analysis. QUADAS-2 evaluation was adopted for quality analyses. [⁶⁸Ga]PSMA-11 was the radiotracer of choice in 15 studies, while [⁶⁸Ga]PSMA-617 was used in another 3. In 8 articles, there was a direct comparison with mpMRI. The total number of patients included was 1379, ranging from 15 to 291, with a median age of 64 years (range: 42–90). The median baseline PSA value was 12.9 ng/mL, ranging from 0.85 to 4156 ng/mL. Some studies evaluated the PSMA uptake comparing the SUVmax of suspicious lesions with the SUVmax of the normal biodistribution to find out optimal cut-off points. In addition, some studies suggested a significant association between PSA levels, PSA density, and [⁶⁸Ga]PSMA PET/CT finding. [⁶⁸Ga]PSMA PET/CT seems to be more accurate in identifying primary prostate cancer with PSA values between 4 and 20 ng/mL than mpMRI. Moreover, in some trials, the combination of PSMA PET/CT and MRI improved the NPV in the detection of clinically significant prostate cancer (csPCa) than MRI alone. Our findings are limited by the small numbers of studies and patient heterogeneity. [⁶⁸Ga]PSMA PET/CT is a promising technique in patients with clinical suspicion of PCa and precedent negative biopsy or contraindications to MRI. Furthermore, its use combined with MRI improves sensitivity for csPCa detection and can avoid unnecessary biopsies.

Comparison of Multiparametric Magnetic Resonance Imaging with Prostate-Specific Membrane Antigen Positron-Emission Tomography Imaging in Primary Prostate Cancer Diagnosis: A Systematic Review and Meta-Analysis

Multiparametric magnetic-resonance imaging (mpMRI) has proven utility in diagnosing primary prostate cancer. However, the diagnostic potential of prostate-specific membrane antigen positron-emission tomography (PSMA PET) has yet to be established. This study aims to systematically review the current literature comparing the diagnostic performance of mpMRI and PSMA PET imaging to diagnose primary prostate cancer. A systematic literature search was performed up to December 2021. Quality analyses were conducted using the QUADAS-2 tool. The reference standard was whole-mount prostatectomy or prostate biopsy. Statistical analysis involved the pooling of the reported diagnostic performances of each modality, and differences in per-patient and per-lesion analysis were compared using a Fisher’s exact test. Ten articles were included in the meta-analysis. At a per-patient level, the pooled values of sensitivity, specificity, and area under the curve (AUC) for mpMRI and PSMA PET/CT were 0.87 (95% CI: 0.83−0.91) vs. 0.93 (95% CI: 0.90−0.96, p < 0.01); 0.47 (95% CI: 0.23−0.71) vs. 0.54 (95% CI: 0.23−0.84, p > 0.05); and 0.84 vs. 0.91, respectively. At a per-lesion level, the pooled sensitivity, specificity, and AUC value for mpMRI and PSMA PET/CT were lower, at 0.63 (95% CI: 0.52−0.74) vs. 0.79 (95% CI: 0.62−0.92, p < 0.001); 0.88 (95% CI: 0.81−0.95) vs. 0.71 (95% CI: 0.47−0.90, p < 0.05); and 0.83 vs. 0.84, respectively. High heterogeneity was observed between studies. PSMA PET/CT may better confirm the presence of prostate cancer than mpMRI. However, both modalities appear comparable in determining the localisation of the lesions.

Validation of a Portable Whole-Slide Imaging System for Frozen Section Diagnosis

Background

Frozen section (FS) diagnosis is one of the promising applications of digital pathology (DP). However, the implementation of an appropriate and economically viable DP solution for FS in routine practice is challenging. The objective of this study was to establish the non-inferiority of whole-slide imaging (WSI) versus optical microscopy (OM) for FS diagnosis using a low cost and portable DP system.

Materials and Methods

A validation study to investigate the technical performance and diagnostic accuracy of WSI versus OM for FS diagnosis was performed using 60 FS cases[120 slides i.e, 60 hematoxylin and eosin (H & E) and 60 toluidine blue (TOLB)]. The diagnostic concordance, inter- and intra-observer agreement for FS diagnosis by WSI versus OM were recorded.

Results

The first time successful scanning rate was 89.1% (107/120). Mean scanning time per slide for H and E and TOLB slide was 1:47 min (range; 0:22-3: 21 min) and 1:46 min (range; 0:21-3: 20 min), respectively. Mean storage space per slide for H and E and TOLB slide was 0.83 GB (range: 0.12-1.73 GB) and 0.71 GB (range: 0.11-1.66 GB), respectively. Considering major discrepancies, the overall diagnostic concordance for OM and WSI, when compared with the reference standard, was 95.42% and 95.83%, respectively. There was almost perfect intra as well as inter-observer agreement (k ≥ 0.8) among 4 pathologists between WSI and OM for FS diagnosis. Mean turnaround time (TAT) of 14:58 min was observed using WSI for FS diagnosis, which was within the College of American Pathologists recommended range for FS reporting. The image quality was average to best quality in most of the cases.

Conclusion

WSI was noninferior to OM for FS diagnosis across various specimen types. This portable WSI system can be safely adopted for routine FS diagnosis and provides an economically viable alternative to high-end scanners.

A Survival Guide for the Rapid Transition to a Fully Digital Workflow: The "Caltagirone Example"

Digital pathology for the routine assessment of cases for primary diagnosis has been implemented by few laboratories worldwide. The Gravina Hospital in Caltagirone (Sicily, Italy), which collects cases from 7 different hospitals distributed in the Catania area, converted the entire workflow to digital starting from 2019. Before the transition, the Caltagirone pathology laboratory was characterized by a non-tracked workflow, based on paper requests, hand-written blocks and slides, as well as manual assembling and delivering of the cases and glass slides to the pathologists. Moreover, the arrangement of the spaces and offices in the department was illogical and under-productive for the linearity of the workflow. For these reasons, an adequate 2D barcode system for tracking purposes, the redistribution of the spaces inside the laboratory and the implementation of the whole-slide imaging (WSI) technology based on a laboratory information system (LIS)-centric approach were adopted as a needed prerequisite to switch to a digital workflow. The adoption of a dedicated connection for transfer of clinical and administrative data between different software and interfaces using an internationally recognised standard (Health Level 7, HL7) in the pathology department further facilitated the transition, helping in the integration of the LIS with WSI scanners. As per previous reports, the components and devices chosen for the pathologists' workstations did not significantly impact on the WSI-based reporting phase in primary histological diagnosis. An analysis of all the steps of this transition has been made retrospectively to provide a useful "handy" guide to lead the digital transition of "analog", non-tracked pathology laboratories following the experience of the Caltagirone pathology department. Following the step-by-step instructions, the implementation of a paperless routine with more standardized and safe processes, the possibility to manage the priority of the cases and to implement artificial intelligence (AI) tools are no more an utopia for every "analog" pathology department.

Comparative Assessment of Digital Pathology Systems for Primary Diagnosis

Background:

Despite increasing interest in whole-slide imaging (WSI) over optical microscopy (OM), limited information on comparative assessment of various digital pathology systems (DPSs) is available.

Materials and Methods:

A comprehensive evaluation was undertaken to investigate the technical performance–assessment and diagnostic accuracy of four DPSs with an objective to establish the noninferiority of WSI over OM and find out the best possible DPS for clinical workflow.

Results:

A total of 2376 digital images, 15,775 image reads (OM - 3171 + WSI - 12,404), and 6100 diagnostic reads (OM - 1245, WSI - 4855) were generated across four DPSs (coded as DPS: 1, 2, 3, and 4) using a total 240 cases (604 slides). Onsite technical evaluation revealed successful scan rate: DPS3 < DPS2 < DPS4 < DPS1; mean scanning time: DPS4 < DPS1 < DPS2 < DPS3; and average storage space: DPS3 < DPS2 < DPS1 < DPS4. Overall diagnostic accuracy, when compared with the reference standard for OM and WSI, was 95.44% (including 2.48% minor and 2.08% major discordances) and 93.32% (including 4.28% minor and 2.4% major discordances), respectively. The difference between the clinically significant discordances by WSI versus OM was 0.32%. Major discordances were observed mostly using DPS4 and least in DPS1; however, the difference was statistically insignificant. Almost perfect (κ ≥ 0.8)/substantial (κ = 0.6–0.8) inter/intra-observer agreement between WSI and OM was observed for all specimen types, except cytology. Overall image quality was best for DPS1 followed by DPS4. Mean digital artifact rate was 6.8% (163/2376 digital images) and maximum artifacts were noted in DPS2 (n = 77) followed by DPS3 (n = 36). Most pathologists preferred viewing software of DPS1 and DPS2.

Conclusion:

WSI was noninferior to OM for all specimen types, except for cytology. Each DPS has its own pros and cons; however, DPS1 closely emulated the real-world clinical environment. This evaluation is intended to provide a roadmap to pathologists for the selection of the appropriate DPSs while adopting WSI.

Improved Primary Staging of Marginal-Zone Lymphoma by Addition of CXCR4-Directed PET/CT

PET/CT with ¹⁸F-FDG is an integral component in the primary staging of most lymphomas. However, its utility is limited in marginal-zone lymphoma (MZL) because of inconsistent ¹⁸F-FDG avidity. One diagnostic alternative could be the targeting of C-X-C motif chemokine receptor 4 (CXCR4), shown to be expressed by MZL cells. This study investigated the value of adding CXCR4-directed ⁶⁸Ga-pentixafor PET/CT to conventional staging. Methods: Twenty-two newly diagnosed MZL patients were staged conventionally and with CXCR4 PET/CT. Lesions identified exclusively by CXCR4 PET/CT were biopsied as the standard of reference and compared with imaging results. The impact of CXCR4-directed imaging on staging results and treatment protocol was assessed. Results: CXCR4 PET/CT correctly identified all patients with viable MZL and was superior to conventional staging (P < 0.001). CXCR4-directed imaging results were validated by confirmation of MZL in 16 of 18 PET-guided biopsy samples. Inclusion of CXCR4 PET/CT in primary staging significantly impacted staging results in almost half of patients and treatment protocols in a third (upstaging, n = 7; downstaging, n = 3; treatment change, n = 8; P < 0.03). Conclusion: CXCR4 PET/CT is a suitable tool in primary staging of MZL and holds the potential to improve existing diagnostic algorithms.

Medication Intervention for Chronic Kidney Disease Patients Transitioning from Hospital to Home: Study Design and Baseline Characteristics

BACKGROUND

The hospital readmission rate in the population with chronic kidney disease (CKD) is high and strategies to reduce this risk are urgently needed.

METHODS

The CKD-Medication Intervention Trial (CKD-MIT; www.clinicaltrials.gov; NCTO1459770) is a single-blind (investigators), randomized, clinical trial conducted at Providence Health Care in Spokane, Washington. Study participants are hospitalized patients with CKD stages 3-5 (not treated with kidney replacement therapy) and acute illness. The study intervention is a pharmacist-led, home-based, medication management intervention delivered within 7 days after hospital discharge. The primary outcome is a composite of hospital readmissions and visits to emergency departments and urgent care centers for 90 days following hospital discharge. Secondary outcomes are achievements of guideline-based targets for CKD risk factors and complications.

RESULTS

Enrollment began in February 2012 and ended in May 2015. At baseline, the age of participants was 69 ± 11 years (mean ± SD), 50% (77 of 155) were women, 83% (117 of 141) had hypertension and 56% (79 of 141) had diabetes. At baseline, the estimated glomerular filtration rate was 41 ± 14 ml/min/1.73 m2 and urine albumin-to-creatinine ratio was 43 mg/g (interquartile range 8-528 mg/g). The most frequent diagnosis category for the index hospital admission was cardiovascular diseases at 34% (53 of 155), but the most common single diagnosis for admission was community-acquired acute kidney injury at 10% (16 of 155).

CONCLUSION

Participants in CKD-MIT are typical of acutely ill hospitalized patients with CKD. A medication management intervention after hospital discharge is under study to reduce post-hospitalization acute care utilization and to improve CKD management.

Issues in using whole slide imaging for diagnostic pathology: "routine" stains, immunohistochemistry and predictive markers

The traditional microscope, together with the "routine" hematoxylin and eosin (H & E) stain, remains the "gold standard" for diagnosis of cancer and other diseases; remarkably, it and the majority of associated biological stains are more than 150 years old. Immunohistochemistry has added to the repertoire of "stains" available. Because of the need for specific identification and even measurement of "biomarkers," immunohistochemistry has increased the demand for consistency of performance and interpretation of staining results. Rapid advances in the capabilities of digital imaging hardware and software now offer a realistic route to improved reproducibility, accuracy and quantification by utilizing whole slide digital images for diagnosis, education and research. There also are potential efficiencies in work flow and the promise of powerful new analytical methods; however, there also are challenges with respect to validation of the quality and fidelity of digital images, including the standard H & E stain, so that diagnostic performance by pathologists is not compromised when they rely on whole slide images instead of traditional stained tissues on glass slides.