Lymph node imaging in initial staging of prostate cancer: An overview and update

Lighthouses illuminating tumor metastasis: The application of fluorescent probes in the localization and imaging metastatic lymph nodes across various tumors

The significance of metastatic lymph nodes in tumor diagnosis and prognosis is self-evident. With the deepening of research on the lymphatic system and the advancement of imaging technology, an increasing number of near-infrared fluorescent probes targeting tumor metastatic lymph nodes have been developed. These probes can identify tumors while further detecting lymph nodes (LNs), showcasing great potential in image-guided surgery. In this review, we comprehensively outline the design strategies and applications of near-infrared fluorescent probes for cancers with a high propensity for lymph node metastasis during disease progression. Particular emphasis is placed on two targeting mechanisms: tumor-directed probes capable of identifying metastatic lymph nodes and lymph node-specific probes utilizing passive targeting of metastatic lymph nodes or active targeting of lymph nodes directly. Additionally, we discuss current issues and future prospects in this field, which will facilitate the development of new fluorescent probes and their further clinical translation.

From Oncogenesis to Theranostics: The Transformative Role of PSMA in Prostate Cancer

Prostate cancer, a leading cause of cancer-related mortality among men, is characterized by complex genetic and epigenetic alterations, dysregulation of oncogenic pathways, and a dynamic tumor microenvironment. Advances in molecular diagnostics and targeted therapies have significantly transformed the management of this disease. Prostate-specific membrane antigen (PSMA) has emerged as a critical biomarker, enhancing the precision of prostate cancer diagnosis and treatment. Theranostics, which integrates PSMA-targeted imaging with radioligand therapies, has shown remarkable efficacy in detecting and treating advanced prostate cancer. By leveraging the dual capabilities of PSMA-based diagnostics and therapeutic agents, theranostics offers a personalized approach that improves patient outcomes. This comprehensive review explores the latest developments in PSMA-targeted theranostics and their impact on the future of prostate cancer management, highlighting key clinical trials and emerging therapeutic strategies.

The Value of Dual Time Point 18F-FDG PET/CT Imaging in Differentiating Lymph Node Metastasis From Reactive Hyperplasia in Bladder Urothelial Carcinoma

RATIONALE AND OBJECTIVES

This study explored the clinical value of dual time-point 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) imaging for differentiating lymph node metastasis from lymph nodes with reactive hyperplasia.

METHODS

250 lymph nodes from 153 bladder cancer patients who underwent 18F-FDG PET/computed tomography (CT) delayed diuretic imaging were analyzed. The maximum and mean standardized uptake values (SUVmax and SUVmean, respectively), metabolic tumor volume (MTV), and related delay indices before and after PET delayed imaging were obtained. Relationships with outcomes were analyzed using nonparametric and multivariate analyses. Receiver operating characteristic curves and nomograms were drawn to predict lymph node metastasis.

RESULTS

Delayed PET/CT imaging showed better detection of hyperplasia and metastatic lymph nodes. Delayed imaging with a cutoff SUVmax of 2.0 or 2.5 increased the detection rate of metastatic lymph nodes by 4.1%, and 6.9%, respectively. Delayed imaging often showed speckle-like radioactive foci in lymph nodes with reactive hyperplasia and increased FDG uptake throughout the nodes in metastatic lymph nodes. The lymph node short-axis diameter, SUVmean, and delayed index of MTV (DIMTV) were independent predictors for differentiating metastatic lymph nodes from reactive hyperplasia, and their combination showed better differentiation performance than the individual predictors. In high-risk patients, the probability of lymph node metastasis was as high as 97.6%.

CONCLUSION

Dual time-point imaging can detect more metastatic lymph nodes. Some lymph nodes with hyperplasia show speckle-like radioactive foci on delayed imaging. The lymph node short-axis diameter, SUVmean, and DIMTV are three important parameters for predicting lymph node metastasis.

Diagnostic Accuracy of Molecular Imaging Techniques for Detecting Prostate Cancer: A Systematic Review

Molecular imaging modalities show valuable non-invasive techniques capable of precisely and selectively addressing molecular markers associated with prostate cancer (PCa). This systematic review provides an overview of imaging markers utilized in positron emission tomography (PET) methods, specifically focusing on the pathways and mediators involved in PCa. This systematic review aims to evaluate and analyse existing literature on the diagnostic accuracy of molecular imaging techniques for detecting PCa. The PubMed, EBSCO, ScienceDirect, and Web of Science databases were searched, identifying 32 studies that reported molecular imaging modalities for detecting PCa. Numerous imaging modalities and radiotracers were used to detect PCa, including 68Ga-prostate-specific membrane antigen (PSMA) PET/computed tomography (CT), 68Ga-PSMA-11 PET/magnetic resonance imaging (MRI), 18F-PSMA-1007 PET/CT, 18F-DCFPyL PET/MRI, 18F-choline PET/MRI, and 18F-fluoroethylcholine PET/MRI. Across 11 studies, radiolabelled 68Ga-PSMA PET/CT imaging had a pooled sensitivity of 80 (95% confidence interval [CI]: 35-93), specificity of 90 (95% CI: 71-98), and accuracy of 86 (95% CI: 64-96). The PSMA-ligand 68Ga-PET/CT showed good diagnostic performance and appears promising for detecting and staging PCa.

Reasons for Discordance between 68Ga-PSMA-PET and Magnetic Resonance Imaging in Men with Metastatic Prostate Cancer

BACKGROUND

PSMA PET has emerged as a "gold standard" imaging modality for assessing prostate cancer metastases. However, it is not universally available, and this limits its impact. In contrast, whole-body MRI is much more widely available but misses more lesions. This study aims to improve the interpretation of whole-body MRI by comparing false negative scans retrospectively to PSMA PET.

METHODS

This study was a retrospective sub-analysis of a prospectively collected database of patients who participated in a clinical trial of PSMA PET/MRI comparing PSMA PET and whole-body MRI from 2018-2021. Subjects whose separately read PSMA PET and MRI diagnostic reports showed discrepancies ("false negative" MRI cases) were selected for sub-analysis. The cases were reviewed by the same attending radiologist who originally read the scans. The radiologist noted specific features on MRI indicating metastatic disease that were initially missed.

RESULTS

Of 263 cases, 38 (14%) met the inclusion criteria and were reviewed. Six classes of mpMRI false negatives were identified: anatomically normal (18, 47%), atypical MRI appearance (6, 16%), mischaracterization (1, 3%), undercall (6, 16%), obscured (4, 11%), and no abnormality on MRI (3, 8%). Considering that the atypical and undercalled cases could have been adjusted in retrospect, and that 4 additional cases had positive lesions to the same extent and 11 further cases had disease confined to the pelvis, only 11 (4%) of the original 263 would have had disease outside of a conventional radiation treatment plan.

CONCLUSION

Notably, almost 50% of the cases, including most lymph node metastases, were anatomically normal using standard criteria. This suggests that current anatomic criteria for evaluating prostate cancer lymph node metastases are not ideal, and there is a need for improved criteria. In addition, 32% of cases involved some element of human interpretive error, and, therefore, improving reader training may lead to more accurate results.

18 F-prostate specific membrane antigen positron emission tomography/computerized tomography for lymph node staging in medium/high risk prostate cancer: A systematic review and meta-analysis

BACKGROUND

Lymph node staging of prostate cancer (PCa) is important for planning and monitoring of treatment. 18 F-prostate specific membrane antigen positron emission tomography/computerized tomography ( 18 F-PSMA PET/CT) has several advantages over 68 Ga-PSMA PET/CT, but its diagnostic value requires further investigation. This meta-analysis focused on establishing the diagnostic utility of 18 F-PSMA PET/CT for lymph node staging in medium/high-risk PCa.

METHODS

We searched the EMBASE, PubMed, Cochrane library, and Web of Science databases from inception to October 1, 2022. Prostate cancer, 18 F, lymph node, PSMA, and PET/CT were used as search terms and the language was limited to English. We additionally performed a manual search using the reference lists of key articles. Patients and study characteristics were extracted and the QUADAS-2 tool was employed to evaluate the quality of included studies. Sensitivity, specificity, the positive and negative likelihood ratio (PLR and NLR), diagnostic odds ratio (DOR), area under the curve (AUC), and 95% confidence interval (CI) were used to evaluate the diagnostic value of 18 F-PSMA PET/CT. Stata 17 software was employed for calculation and statistical analyses.

RESULTS

A total of eight diagnostic tests including 734 individual samples and 6346 lymph nodes were included in this meta-analysis. At the patient level, the results of each consolidated summary were as follows: sensitivity of 0.57 (95% CI 0.39-0.73), specificity of 0.95 (95% CI 0.92-0.97), PLR of 11.2 (95% CI 6.6-19.0), NLR of 0.46 (95% CI 0.31-0.68), DOR of 25 (95% CI 11-54), and AUC of 0.94 (95% CI 0.92-0.96). At the lesion level, the results of each consolidated summary were as follows: sensitivity of 0.40 (95% CI 0.21-0.62), specificity of 0.99 (95% CI 0.95-1.00), PLR of 40.0 (95% CI 9.1-176.3), NLR of 0.61 (95% CI 0.42-0.87), DOR of 66 (95% CI 14-311), and AUC of 0.86 (95% CI 0.83-0.89).

CONCLUSIONS

18 F-PSMA PET/CT showed moderate sensitivity but high specificity in lymph node staging of medium/high-risk PCa. The diagnostic efficacy was almost equivalent to that reported for 68 Ga-PSMA PET/CT.

REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO), No. CRD42023391101.

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 Hunt for Lymph Nodes: Is Total Submission of Standard-Template and Extended-Template Pelvic Lymph Node Dissections Necessary for Detecting Metastatic Prostate Cancer?

CONTEXT.—

There are no consensus guidelines on submission of pelvic lymph node dissection (PLND) specimens for radical prostatectomies. Complete submission is only performed by a minority of laboratories. Our institution has been following this practice for standard-template and extended-template PLND.

OBJECTIVE.—

To investigate the utility of total submission of PLND specimens for prostate cancer and understand its impact on patients and the laboratory.

DESIGN.—

Retrospective study examining 733 cases of radical prostatectomies with PLND performed at our institution. Reports and slides with positive lymph nodes (LNs) were reviewed. Data on LN yield, cassette usage, and impact of submission of remaining fat after dissection of grossly identifiable LNs were assessed.

RESULTS.—

Most cases involved submission of extra cassettes for remaining fat (97.5%, n = 697 of 715). Extended PLND yielded a higher mean number of total and positive LNs versus standard PLND (P < .001). However, extended PLND required significantly more cassettes for remaining fat (mean, 8; range, 0-44). There was poor correlation between number of cassettes submitted for PLND with total and positive LN yield and between remaining fat with LN yield. Most positive LNs were grossly identified (88.5%, n = 139 of 157) and were typically larger than those not. Only 4 cases (0.6%, n = 4 of 697) would have been understaged without complete submission of PLND.

CONCLUSIONS.—

Total submission of PLND increases detection of metastasis and LN yield yet increases workload significantly with only minimal patient management impact. Hence, we recommend that meticulous gross identification and submission of all LNs be pursued without the need to submit the remaining fat of PLND.

Clinical Significance of Radical Prostatectomy in Clinical Lymph Node Metastasis in Prostate Cancer

BACKGROUND

This study aimed to investigate the role of radical prostatectomy (RP) among clinical nodal metastasis prostate cancer and whether histological confirmation of lymph node metastasis through surgery can help with treatment.

PATIENTS AND METHODS

After excluding patients with distant metastatic prostate cancer or neoadjuvant androgen deprivation therapy, 42 patients with clinical nodal metastasis who underwent RP at our institution were included in the study. We classified them as having or not having pathological lymph node metastasis. Clinicopathologic data were analyzed in this retrospective chart review. Kaplan-Meier analysis was used to calculate the estimated castration-resistant prostate cancer (CRPC)-free survival, biochemical recurrence (BCR)-free survival, and cancer-specific survival (CSS).

RESULTS

There is no significant difference in age, presence of diabetes mellitus, hypertension, BCR time, CRPC time, overall survival, salvage RT rate, and initial prostate-specific antigen level between the two groups. However, there is a significant difference in the pathology N1 group in terms of pathological T stage, pathologic Gleason score, BCR rate, CRPC rate, and CSS. A multivariate Cox proportional hazard regression analysis was used to identify predictors of CRPC-free survival. Patients with pathological lymph node metastasis had a shorter CRPC-free survival [hazard ratio (HR) 4.87; 95% confidence interval (CI) 1.25-19.00, p = 0.02].

CONCLUSION

Radical prostatectomy can confirm lymph node metastasis. Although pathologic diagnosis has no effect on time to BCR and CPRC, because it affects BCR rate, CRPC rate, and CSS, an accurate pathological diagnosis obtained through surgery is beneficial in the treatment of clinical lymph node metastasis prostate cancer.

Stereotactic Body Radiation Therapy Salvage for Lymph Node Recurrent Prostate Cancer in the Era of PSMA PET Imaging

PURPOSE OF REVIEW

Our understanding of patterns of prostate cancer recurrence after primary treatment of localized disease has significantly evolved since the development of positron emission tomography (PET) agents targeting prostate cancer. Previously, most biochemical recurrences were not associated with imaging correlates when restaging with computed tomography (CT), magnetic resonance imaging (MRI), or bone scintigraphy and, hence, were typically assumed to represent occult metastases. A rising prostate specific antigen (PSA) after previous local therapy prompting a PET scan showing uptake limited to regional lymph nodes is an increasingly common clinical scenario as advanced prostate cancer imaging becomes more widely utilized. The optimal management strategy for patients who have lymph node recurrent prostate cancer is both unclear and evolving, particularly in terms of local and regionally directed therapies. Stereotactic body radiation therapy (SBRT) utilizes ablative radiation doses with steep gradients to achieve local tumor control while sparing nearby normal tissues. SBRT is an attractive therapeutic modality due to its efficacy, favorable toxicity profile, and flexibility to administer elective doses to areas of potential occult involvement. The purpose of this review is to briefly describe how SBRT is being implemented in the era of PSMA PET for the management of solely lymph node recurrent prostate cancer.

RECENT FINDINGS

SBRT has been shown to effectively control individual lymph node tumor deposits within the pelvis and retroperitoneum for prostate cancer and is well-tolerated with a favorable toxicity profile. However, a major limitation thus far has been the lack of prospective trials supporting the use of SBRT for oligometastatic nodal recurrent prostate cancer. As further trials are conducted, its exact role in the treatment paradigm of recurrent prostate cancer will be better established. Although PET-guided SBRT appears feasible and potentially beneficial, there is still considerable uncertainty about the use of elective nodal radiotherapy (ENRT) in patients with nodal recurrent oligometastatic prostate cancer. PSMA PET has undoubtedly advanced imaging of recurrent prostate cancer, revealing anatomic correlates for disease recurrence that previously went undetected. At the same time, SBRT continues to be explored in prostate cancer with feasibility, a favorable risk profile, and satisfactory oncologic outcomes. However, much of the existing literature comes from the pre-PSMA PET era and integration of this novel imaging approach has led to greater focus on new and ongoing clinical trials to rigorously evaluate this approach and compare to other established treatment modalities utilized for oligometastatic, nodal recurrence of prostate cancer.

Lymphotropic nanoparticle magnetic resonance imaging for diagnosing metastatic lymph nodes in dogs with malignant head and neck tumours

Lymphotropic nanoparticle magnetic resonance imaging (LNMRI) utilises ultrasmall paramagnetic iron nanoparticles (USPIOs) for imaging of metastatic lymph nodes in patients afflicted with cancer. LNMRI has been shown to be a highly effective and accurate way to diagnose metastasis in humans but has not been commonly reported on in veterinary medicine. USPIOs are phagocytised by macrophages and then localised to lymph nodes where they create a susceptibility artefact on gradient echo MRI sequences. In this study dogs (n = 24) with naturally occurring head and neck tumours were imaged with LNMRI then had mandibular and retropharyngeal lymph nodes extirpated for histological analysis. Subjective and objective analysis of the LNMRI images was performed and imaging results compared to histology as the gold standard. A total of 149 lymph nodes were included in this study. The overall sensitivity, specificity and accuracy was 64%, 94.4% and 89.3% respectively. However, if dogs with mast cell tumours were excluded from analysis the sensitivity, specificity and accuracy rose to 85.7%, 95.7% and 94.6%. LNMRI is potentially an accurate way to determine the presence of lymph node metastasis in dogs with some types of head and neck tumours. However, LNMRI has only moderate accuracy in dogs with oral or mucocutaneous mast cell tumours in this region.

MRI fat fraction imaging of nodal and bone metastases in prostate cancer

KEY POINTS

• Characterisation and quantification of tissue fat on MRI can be used to provide information on disease processes. • Fat in bone and lymph nodes up until recently have not been exploited for diagnostic purposes or response monitoring in prostate cancer. • Fat imaging on MRI using Dixon/PDFF sequences has the potential to add clinical value in the future but prospective data is needed.

Safety and Efficacy of CT-Guided Percutaneous Biopsy of Suspicious Subcentimeter Pelvic and Retroperitoneal Lymph Nodes Detected by 11C-Choline PET in Patients With Prostate Cancer

BACKGROUND. In patients with prostate cancer, PET using targeted radiotracers can identify increased activity in small morphologically normal lymph nodes, facilitating earlier detection of metastatic disease. OBJECTIVE. The purpose of this article was to assess the efficacy and safety of CT-guided biopsy of suspicious pelvic and retroperitoneal lymph nodes measuring smaller than 1 cm detected by 11C-choline PET in patients with prostate cancer, with comparison with nodes measuring 1 cm or larger. METHODS. This retrospective study included patients with prostate cancer who underwent CT-guided percutaneous biopsy of suspicious pelvic or retroperitoneal lymph nodes detected by 11C-choline PET/CT or PET/MRI (performed because of a rising or elevated PSA level or known recurrent or metastatic disease) between June 1, 2012, and March 20, 2020. Patient, lymph node, and procedural characteristics, as well as biopsy outcomes and complications, were recorded. Biopsies of lymph nodes measuring smaller than 1 cm and of lymph nodes measuring 1 cm and larger were compared. RESULTS. A total of 269 patients (mean age, 68.7 ± 6.8 [SD] years) were included. A total of 156 patients underwent biopsy of lymph nodes measuring smaller than 1 cm (range, 3-9 mm); 113 patients underwent biopsy of lymph nodes measuring 1 cm or larger (range, 10-35 mm). Lymph nodes smaller than 1 cm and lymph nodes 1 cm and larger showed no significant difference in diagnostic yield (89.7% vs 92.9%; p = .40). Diagnostic yield was not significantly different between nodes smaller than 1 cm and nodes 1 cm and larger for any individual anatomic location within the pelvis or retroperitoneum (all p > .05). Malignant yield was lower for nodes smaller than 1 cm than for nodes 1 cm and larger (44.9% vs 63.7%; p = .003). The single biopsied 3-mm node had a nondiagnostic specimen. Diagnostic yield and malignant yield were 100.0% and 40.0%, respectively, for 4-mm nodes, and 95.5% and 45.5%, respectively, for 5-mm nodes. Patients with nodes smaller than 1 cm and nodes 1 cm and larger showed no significant difference in minor (12.8% vs 7.1%; p = .16) or major (0.6% vs 2.7%; p = .31) complication rate. CONCLUSION. The findings support the safety and efficacy of CT-guided biopsy of suspicious subcentimeter pelvic and retroperitoneal lymph nodes detected on 11C-choline PET in patients with prostate cancer. CLINICAL IMPACT. Earlier diagnosis of metastatic lymphadenopathy will impact prognostic assessment and management decisions in patients with recurrent prostate cancer.

The combination of prostate MRI PI-RADS scoring system and a genomic classifier is associated with pelvic lymph node metastasis at the time of radical prostatectomy

OBJECTIVE

Pelvic lymph node metastasis (PLNM) at the time of radical prostatectomy (RP) portends an unfavorable prognosis in prostate cancer patients. Conventional and advanced imaging remains limited in its ability to detect PLNM. We sought to evaluate the combination of a genomic classifier Decipher with Prostate Imaging Reporting and Data System (PI-RADS) scores in improving the detection of PLNM.

METHODS

A retrospective review was performed of patients whom underwent RP, Decipher analysis, and pre-operative prostate MRI. Categorical variables were compared using Pearson chi-squareχ2 tests. Quantitative variables were assessed with Wilcoxon rank-sum tests. Multivariable logistic regression was used to identify predictors of PLNM on final pathology.

RESULTS

In total, 202 patients were included in the analysis, 23 of whom (11%) had PLNM. Patients with PLNM had higher median Decipher scores (0.73) than those without PLNM (0.61; p = 0.003). Patients with PLNM were more likely to demonstrate PI-RADS scores ≥ 4 (96%) than those without PLNM (74%; p = 0.012). Logistic regression demonstrated an interaction between Decipher score with PI-RADS score ≥4 (OR = 20.41; 95% CI, 2.10-198.74; p = 0.009) The combination demonstrated an area under the curve (AUC) of 0.73 (95% CI, 0.63-0.82; p < 0.001) for predicting PLNM.

CONCLUSION

The combination of elevated Decipher genomic score (≥ 0.6) and clinically significant PI-RADS score (≥ 4) is associated with PLNM at the time of RP in a modern high-risk cohort of patients with PCaprostate cancer.

ADVANCES IN KNOWLEDGE

Prostate MRI and genomic testing may help identify patients with adverse pathology.

Optimization of prostate cancer patient lymph node staging via the integration of neutrophil-lymphocyte ratios, platelet-lymphocyte ratios, and 68 Ga-PSMA-PET-derived SUVmax values

BACKGROUND

At present, standardized parameters for quantitatively evaluating ⁶⁸ Ga-PSMA-PET/CT outcomes when diagnosing lymph node metastasis in prostate cancer patients are lacking. Inflammatory hematological biomarkers offer value as robust predictors of certain cancer-related outcomes. The present study was thus developed to explore approaches to improving the utility of ⁶⁸ Ga-PSMA-PET/CT for diagnosing lymph node metastasis through the combined evaluation of inflammatory hematological markers in prostate cancer patients.

METHODS

Pretreatment patient details including age, initial TPSA levels, hematological findings, biopsy pathology results (Gleason score and ISUP grouping), radical pathology results, and imaging details were collected. Optimal cutoff values for each predictor then being determined based upon Youden's index, with univariate and multivariate analyses were then used to identify independent predictors of lymph node metastasis and used to construct a nomogram.

RESULT

Independent predictors of lymph node metastasis in this patient cohort included SUVmax (odds ratio [OR]: 30.549, 95% confidence interval [CI]: 10.855-85.973, p < 0.001), neutrophil-lymphocyte ratio (OR:8.221, 95%CI: 1.335-50.614, p = 0.023), platelet-lymphocyte ratio (OR:8.221, 95% CI: 1.335-50.614, p = 0.023), initial TPSA (OR:2.761, 95% CI: 1.132-6.733, p = 0.026), and clinical T-stage (T3 vs. T2, OR:11.332, 95% CI:3.929-32.681, p < 0.001; T4 vs. T2, OR:9.101, 95% CI:1.962-42.213, p = 0.005), with corresponding optimal cutoff values of 2.3 (area under the curve [AUC]: 0.873, sensitivity: 0.736, specificity: 0.902), 1.72 (AUC: 0.558, sensitivity: 0.529, specificity: 0.643), 83.305 (AUC: 0.651, sensitivity: 0.299, specificity: 0.979), and 21.875 (AUC: 0.672, sensitivity: 0.736, specificity: 0.601). Subsequent nomogram construction was associated with good predictive ability, with a C-index of 0.887(95% CI: 0.793-0.981) and an AUC of 0.924 (95% CI: 0.882-0.965).

CONCLUSION

SUVmax, the neutrophil-lymphocyte ratio, the platelet-lymphocyte ratio, initial TPSA, and clinical T-stage represent valuable independent predictors of lymph node metastasis in prostate cancer patients, offering an opportunity to further optimize lymph node staging for these patients.

Benefit of including CT urography in [68Ga]PSMA-11 PET/CT with low-dose CT: first results from a larger prostate cancer cohort analysis

BACKGROUND

Accuracy of [⁶⁸Ga]PSMA-11 PET/CT may be hampered by ureter accumulation, mimicking lymph node metastases depending on localization and configuration. The benefit of CT urography for differentiation of lymph node metastasis from urinary tract activity was evaluated in a "PET/CT with low-dose CT" setting.

METHODS

Retrospective analysis of PET/CT for primary staging, biochemical recurrence or local treatment planning in patients with prostate cancer. For CT urography (CTU), iodinated contrast agent was administered 10 minutes prior to image acquisition. All potential pathologic (peri)ureteral tracer uptake was assigned to excretory ureteral accumulation or pathological lesion. To assess additional provided benefit of CTU all foci were rated with an introduced scoring system (ranging from 0 pts: CTU not needed; up to 3 pts: no differentiation possible without CTU). Success of ureter contrasting was assessed by measurement of Hounsfield units. Besides benefit for reading urography-enhanced PET/CT, the possible impact on subsequent patient treatment was evaluated.

RESULTS

A number of N.=247 patients were included in this study. By CT urography, it was possible to identify each ureter on low-dose CT, with its major part contrasted. In 120/247 (48.6%) patients, urography increased the diagnostic confidence while providing substantial support for interpretation in 60 (24.3%) cases. In 42 (17.0%) patients, urography was clinically relevant (up-/downstaging) with potential impact on subsequent patient care. In 30 of these 42 cases (12.1% of all), discrepant treatment would have resulted from a misdiagnosed tracer accumulation without urography.

CONCLUSIONS

CT urography benefits the interpretation of [⁶⁸Ga]-PSMA-11 PET/CT with low-dose CT and leads to discrepant patient treatment in a small but significant subset of patients (12% in our cohort). The implementation of CT urography into standard protocols of [⁶⁸Ga]PSMA-11 PET/CT with low-dose CT is recommended.

The Impact of the Ongoing COVID-19 Epidemic on the Increasing Risk of Adverse Pathology in Prostate Cancer Patients Undergoing Radical Prostatectomy

We aimed to assess whether the ongoing course of the COVID-19 epidemic has been associated with an increased risk of adverse pathology (AP) findings in prostate cancer (PC) patients treated with radical prostatectomy (RP). We performed a retrospective data analysis which included 408 consecutive, non-metastatic, previously untreated PC patients who underwent RP in our institution between March 2020 and September 2021. Patients were divided into two equally numbered groups in regard to the median surgery date (Early Epidemic [EE] and Late Epidemic [LE]) and compared. Adverse pathology was defined as either grade group (GG) ≥ 4, pT ≥ 3a or pN+ at RP. Patients in the LE group demonstrated significantly higher rates of AP than in the EE group (61 vs. 43% overall and 50 vs. 27% in preoperative non-high-risk subgroup, both p < 0.001), mainly due to higher rates of upgrading. On multivariable analysis, consecutive epidemic week (odds ratio: 1.02, 95% confidence interval: 1.00−1.03, p = 0.009) as well as biopsy GG ≥ 2 and a larger prostate volume (mL) were associated with AP in non-high-risk patients. The study serves as a warning call for increased awareness of risk underassessment in contemporarily treated PC patients.

Role of molecular imaging in the detection of localized prostate cancer

Molecular imaging of prostate cancer continues to grow, with recent inclusion of several positron emission tomography (PET) radiotracers into the recent National Comprehensive Cancer Network guidelines and the US Food and Drug Administration approval of prostate-specific membrane antigen (PSMA)-targeted radiotracers. While much of the work for many of these radiotracers is focused on systemic staging and restaging in both newly diagnosed high-risk prostate cancer and biochemically recurrent disease patients, the potential role of molecular imaging for the detection of localized prostate cancer has not yet been fully established. The primary aim of this article will be to present the potential role for molecular imaging in the detection of localized prostate cancer and discuss potential advantages and disadvantages to utilization of both PET/computed tomography (CT) and PET/magnetic resonance imaging (MRI) for this clinical indication of use.

Recent Advancements in CT and MR Imaging of Prostate Cancer

CT and MRI are both commonly used in prostate cancer (PCa) management, which includes a large spectrum from screening positive pre-diagnosis phase to metastatic disease. CT and MRI have continually evolved to meet the changing demands for PCa management. For CT, novel techniques such as dual energy CT and photon counting CT show promising results for tissue characterization and quantification. For MRI, the detection, staging, and management of prostate cancer has been significantly improved by the development of multiparametric, biparametric, and whole-body MRI techniques. Additionally, research on ultrasmall superparamagnetic particles of iron oxide contrast-enhanced MRI has revealed promising results for nodal staging of PCa. In this manuscript we aim to outline the current status and recent advancements of CT and MRI in PCa imaging.

Utility of 18F-Fluciclovine PET/MRI for Staging Newly Diagnosed High-Risk Prostate Cancer and Evaluating Response to Initial Androgen Deprivation Therapy: A Prospective Single-Arm Pilot Study

BACKGROUND. Despite advances in prostate cancer treatment, rates of biochemical recurrence remain high, relating to lack of detection of small-volume metastatic disease using conventional imaging for initial staging. OBJECTIVE. The purpose of this study was to assess the potential use of 18F-fluciclovine PET/MRI for initial staging of high-risk prostate cancer and evaluating response to androgen deprivation therapy (ADT). METHODS. This prospective clinical trial enrolled 14 men with newly diagnosed high-risk prostate cancer and negative or equivocal conventional staging imaging for metastatic disease between January 2018 and February 2019. All patients underwent pretreatment 18F-fluciclovine PET/MRI including multiparametric prostate MRI; 12 underwent 18F-fluciclovine PET/MRI after surgery or between ADT and radiotherapy. Confidence in identification of the primary intraprostatic lesion and nodal metastases was independently rated on a 0-3 Likert scale by three readers with nuclear medicine experience for 18F-fluciclovine PET/MRI and three readers with abdominal imaging experience for MRI alone. Findings scored as 2 or 3 by at least two readers of a given modality were considered positive. A single reader measured SUVmean, SUVmax, and volume of the MRI-defined intraprostatic lesion and SUVmax of suspicious lymph nodes on PET before and after initiation of ADT. Changes in SUV were analyzed using nonparametric Wilcox-on signed-rank tests. RESULTS. The biopsy-proven lesion in the prostate gland was accurately identified in all 14 patients on both MRI and 18F-fluciclovine PET/MRI. Suspected nodal metastases were detected in three patients on MRI and seven patients on 18F-fluciclovine PET/MRI. After ADT, all patients showed decreased activity within the intraprostatic lesion and/or all suspicious lymph nodes. The primary lesion SUVmean was 4.5 ± 1.1 (range, 2.7-6.5) before treatment and 2.4 ± 1.1 (range, 0.0-3.6) after initiation of ADT (p = .008). For suspicious lymph nodes, the pretreatment SUVmax was 5.5 ± 3.7 (range, 2.8-12.7) and the post-treatment SUVmax was 2.8 ± 1.4 (range, 1.4-5.5) (p = .03). CONCLUSION.18F-labeled fluciclovine PET/MRI shows potential utility in initial staging of high-risk prostate cancer and in evaluating response to ADT. CLINICAL IMPACT. Given the FDA approval and widespread availability of 18F-fluciclovine, the findings could have an impact in the immediate future in guiding initial management of patients with prostate cancer. TRIAL REGISTRATION. ClinicalTrials.gov NCT03264456.

Whole-body magnetic resonance imaging: technique, guidelines and key applications

Whole-body magnetic resonance imaging (WB-MRI) is an imaging method without ionising radiation that can provide WB coverage with a core protocol of essential imaging contrasts in less than 40 minutes, and it can be complemented with sequences to evaluate specific body regions as needed. In many cases, WB-MRI surpasses bone scintigraphy and computed tomography in detecting and characterising lesions, evaluating their response to therapy and in screening of high-risk patients. Consequently, international guidelines now recommend the use of WB-MRI in the management of patients with multiple myeloma, prostate cancer, melanoma and individuals with certain cancer predisposition syndromes. The use of WB-MRI is also growing for metastatic breast cancer, ovarian cancer and lymphoma as well as for cancer screening amongst the general population. In light of the increasing interest from clinicians and patients in WB-MRI as a radiation-free technique for guiding the management of cancer and for cancer screening, we review its technical basis, current international guidelines for its use and key applications.

A narrative review of pelvic lymph node dissection in prostate cancer

Pelvic lymph node dissection (PLND) is an important component in the staging and prognostication of prostate cancer. We performed a narrative review to assess the literature surrounding PLND: (I) the current guideline recommendations and contemporary utilization, (II) the calculation of patient-specific risk to perform PLND using available nomograms, (III) to review the extent of dissection, and its associated outcomes and complications. Due to the improved lymph node yield, better staging, and theoretical improvement in the control of micro-metastatic disease, guidelines have supported the use of (extended-) PLND in patients deemed to be at intermediate or high risk of lymph node involvement (often at a threshold of 5% on modern risk nomograms). However, in practice, real-world utilization of PLND varies considerably due to multiple reasons. Conflicting evidence persists with no clear oncological benefit to PLND, and a small, but important, risk of morbidity. Complications are rare, but include lymphoceles; thromboembolic events; and more rarely, obturator nerve, vascular, and ureteric injury. Furthermore, changing disease incidence and stage migration in the context of earlier detection overall have led to a decreased risk of nodal disease. The trade-offs between the benefits, harms, and risk tolerance/threshold must be carefully considered between each patient and their clinician.

Pathologic nodal downstaging in men with clinically involved lymph nodes undergoing radical prostatectomy: Implications for definitive locoregional therapy

A prostate cancer (CaP) patient with nonmetastatic but clinical positive lymph nodes (cN+) represents a difficult clinical scenario. We compare overall survival (OS) between cN+ men that underwent radical prostatectomy (RP) and were found to have negative node status (pN) with those found to have positive nodal status (pN+), and assess predictors of discordant nodal status. We queried the National Cancer Data Base between 2004 and 2015 for patients that were cT1-3 cN+ cM0 CaP treated with RP. Patients with 0 nodes, cT4, or cM1 disease were excluded. We compared groups based on pathologic nodal status: Discordant (cN+ -> pN) & Concordant (cN+ -> pN+). Kaplan Meier estimations were used to compare OS. Logistic regression was used to determine possible predictors of nodal status. We find that of 6470 cN+ patients, 1,367 (21.1%) underwent RP, 866 (13.4%) had confirmed nodal status. Discordant status was found in 159 (18.4%) and concordant staging in 707 (81.6%). Differences exist in PSA at diagnosis (7.3 vs. 11.2), biopsy group, # of nodes examined (7 vs. 10), race, and Charlson index. Discordant staging had longer OS compared to Concordant staging (P = 0.007) and similar OS to a 3:1 matched cohort of high risk localized CaP patients used as reference (P = 0.46). Lower Gleason Score (GG1-3) was associated with an increased likelihood of discordant staging. Clinical nodal staging is associated with a substantial false positive rate. Discordant status had better OS than Concordant status and similar OS to matched patients with localized CaP. Clinical nodal staging may inappropriately lead to noncurative therapy in a substantial number of men with potentially curable disease.

Development of a novel nomogram incorporating platelet-to-lymphocyte ratio for the prediction of lymph node involvement in prostate carcinoma

OBJECTIVE

The available nomograms used to predict lymph node involvement (LNI) are not comprehensive. We sought to derive a novel nomogram incorporating the platelet to lymphocyte ratio (PLR) to predict LNI and compare its performance to validated preoperative risk nomograms in a cohort of men undergoing robotic-assisted radical prostatectomy at our institution.

METHODS

Our electronic health record was queried for patients who underwent robotic-assisted radical prostatectomy with bilateral pelvic lymphadenectomy between 2013 and 2019. A bootstrapped multivariate logistic regression model was constructed for the predictors of LNI while adjusting for other covariates. Then, we used the derived logistic regression formula to estimate each patient's risk (%) for LNI. Individualized risks were also calculated using the following verified nomograms: Briganti-2012, Cagiannos, Godoy, and Memorial Sloan Kettering Cancer Center. Subsequently, we plotted the risks for our nomogram and the 4 verified nomograms into receiver operating characteristics curves. We reported the area under the curve (AUC) for each of the 5 nomograms and the corresponding 95% confidence interval (CI).

RESULTS

The cohort included 173 patients, of which 13.9% demonstrated LNI. LNI was associated with higher preoperative prostate-specific antigen (PSA) ≥ 10 [odds ratio [OR] = 4.89; 95% confidence interval [CI] (1.42-16.83)], higher grade (WHO group ≥ 3)[19.21; (2.23-195.25)], and higher percentage of positive biopsy cores (≥60%) [3.38, (1.04-11.00)]. With every 30-unit increase in PLR the risk of LNI increased by 47%. The nomogram derived from our data had the highest AUC [(AUC 0.877; 95% CI (0.806-0.947)]. The Memorial Sloan Kettering Cancer Center and Briganti 2012 displayed almost congruent ability [0.836; 95% CI (0.758-0.915)] and [0.827; (0.752-0.902)] to identify patients with positive nodes in our cohort with perfect sensitivity and negative predictive value.

CONCLUSION

The nomogram incorporating PLR demonstrated 94.7% sensitivity to predict LNI and avoided pelvic lymphadenectomy in half of the patients at a cut-off between 6.5% and 8.5%. A prospective study with a larger sample is needed to validate our findings.

Is 18F-FDG PET/CT an Accurate Way to Detect Lymph Node Metastasis in Colorectal Cancer: A Systematic Review and Meta-Analysis

Aims

The purpose of this study was to assess the diagnostic value of ¹⁸F-fluorodeoxy-glucose positron emission tomography/computed tomography (FDG PET/CT) for detection of lymph node (LN) metastasis of colorectal cancer. Material and Methods. A computerized search was performed to determine the relevant articles, published before October 2019. Stata Statistical Software, version 15.0, and Meta-Disc (version 1.4) were used for the meta-analysis.

Results

the sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were 0.65, 0.75, 4.57, and 0.37 respectively. Studies that used SUV_max cut-off value (≤2.5) demonstrated the best accuracy.

Conclusion

¹⁸F-FDG PET/CT shows a low sensitivity and high specificity for detecting the metastasis of LNs in patients with newly diagnosed colorectal cancer.

Comparison of cross-sectional imaging techniques for the detection of prostate cancer lymph node metastasis: a critical review

Conventional staging for prostate cancer (PCa) is performed for men diagnosed with unfavorable-intermediate or higher risk disease. Computed tomography (CT) of the abdomen and pelvis and whole body bone scan remains the standard of care for the detection of visceral, nodal, and bone metastasis. The implementation of the 2012 United States Preventive Services Task Force recommendation against routine prostate specific antigen (PSA) screening resulted in a rise of metastatic PCa at the time of diagnosis, emphasizing the importance of effective imaging modalities for evaluating metastatic disease. CT plays a major role in clinical staging at the time of PCa diagnosis, but multi-parametric magnetic resonance imaging (MRI) is now integrated into many prostate biopsy protocols for the detection of primary PCa, and may be a surrogate for CT for nodal staging. Current guidelines incorporate both CT and MRI as appropriate cross-sectional imaging modalities for the identification of nodal metastasis in indicated patients. There is an ongoing debate about the utility of traditional cross-sectional imaging modalities as well as advanced imaging modalities in detection of both organ-confined PCa detection and nodal involvement.

Metastatic prostate cancer to an ischiorectal fossa lymph node identified on multiparametric magnetic resonance imaging

Prostate cancer is the most common noncutaneous malignancy in American men. Its lymphatic drainage is very well established throughout literature. We report the case of a 72-year-old Caucasian male with elevated serum prostate-specific antigen and biopsy-confirmed high-risk prostate cancer who underwent multiparametric magnetic resonance imaging (MRI) for staging and treatment planning. The imaging revealed suspicious lymph nodes in the left ischiorectal and right obturator fossae that were biopsy confirmed as metastatic prostate adenocarcinoma. Herein, we present the divergence from the well-established lymphatic drainage of prostate cancer and the role of MRI in detecting this prostate cancer site of spread.

Locally advanced prostate cancer imaging findings and implications for treatment from the surgical perspective

The anatomy of the prostate is reviewed in the context of discussing the staging of prostate cancer and patterns of tumor spread. The utility of prostate magnetic resonance imaging along with new advancements in tumor staging are discussed specifically in locally advanced disease. What should be included in the radiology report carries a substantial weight to formulate the urologist's decision in regards to the selection of surgical candidates, preoperative planning and avoiding postoperative complications.

Comparison of surgical, oncological, and functional outcomes of robot-assisted and laparoscopic radical prostatectomy in patients with prostate cancer

OBJECTIVE

To compare the oncological and functional outcomes of robot-assisted radical prostatectomy (RARP) and laparoscopic radical prostatectomy (LRP).

MATERIAL AND METHODS

We compared patients who underwent the RARP (n=778) and LRP (n=48) techniques for prostate cancer between January 2008 and July 2017 in our clinic. Patient demographics, preoperative and postoperative data, pathologic evaluation, continence, and potency rates were collected and analyzed retrospectively.

RESULTS

The preoperative and demographic data of the patients we included in our study were similar. The mean operation time estimated blood loss, length of hospitalization, and catheterization time were significantly shorter in the RARP group. The statistical analysis was in favor of robotic prostatectomy in the terms of the mean length of hospitalization, catheterization time, and early (<30 days) and intermediate (31-90 days) complications. Positive surgical margins and biochemical recurrence rates, and recovery of continence and erectile function, were similar in both groups.

CONCLUSION

RARP and LRP in organ-confined prostate cancer are safe and effective methods. Robotic prostatectomy has a shorter operative time, length of hospitalization, catheterization time, and lower early and late complication rates.

Role of Positron Emission Tomography Imaging in Metabolically Active Renal Cell Carcinoma

PURPOSE OF REVIEW

The clinical role of fluorine-18 fluoro-2-deoxyglucose (FDG)-positron emission tomography (PET) in renal cell carcinoma (RCC) is still evolving. Use of FDG PET in RCC is currently not a standard investigation in the diagnosis and staging of RCC due to its renal excretion. This review focuses on the clinical role and current status of FDG PET and PET/CT in RCC.

RECENT FINDINGS

Studies investigating the role of FDG PET in localized RCC were largely disappointing. Several studies have demonstrated that the use of hybrid imaging PET/CT is feasible in evaluating the extra-renal disease. A current review of the literature determines PET/CT to be a valuable tool both in treatment decision-making and monitoring and in predicting the survival in recurrent and metastatic RCC. PET/CT might be a viable option in the evaluation of RCC, especially recurrent and metastatic disease. PET/CT has also shown to play a role in predicting survival and monitoring therapy response.

The involvement of FBP1 in prostate cancer cell epithelial mesenchymal transition, invasion and metastasis by regulating the MAPK signaling pathway

Prostate cancer (PCa) is a frequently occurring malignancy in males, and epithelial mesenchymal transition (EMT) plays a critical role in PCa metastasis. Thus, developing biomarkers inhibiting EMT may provide significance for treatment of PCa. Hence, the aim of the current study was to investigate the mechanism by which FBP1 gene silencing influences PCa cell EMT, invasion and metastasis by mediating the MAPK pathway. PCa cell lines exhibiting the highest FBP1 expression were selected and treated with plasmids of siRNA-FBP1 sequence 1 and 2, pcDNA3.1-Flag-FBP1 (over-expression plasmid of FBP1), U0126 (an inhibitor of the ERK signaling pathway) and PD98059 (an inhibitor of the MEK signaling pathway). Cell proliferation, migration and invasion were detected by MTT assay, wound healing assay and Transwell assay, respectively. The mRNA and protein expression of related factors of EMT and MAPK signaling were determined by RT-qPCR and western blot analysis, respectively. Xenograft tumor growth after inoculation of DU145 cells was regularly analyzed in the nude mice. The positive expression of EMT markers was determined by immunohistochemistry. DU-145 and PC-3 cells displaying the highest FBP1 expression were selected for further analysis. The PCa cells treated with siRNA-FBP1 exhibited increased proliferation, migration rate and invasion, in addition to facilitated xenograft tumor growth. Notably, siRNA-FBP1 was identified to accelerate PCa cell EMT by elevating the expression of Vimentin and N-cadherin while diminishing E-cadherin expression via activation of the MAPK signaling pathway. The aforementioned results were reversed in PCa cells treated by pcDNA3.1-Flag-FBP1. Evidence has been provided in this study that FBP1 gene silencing activates the MAPK pathway, which ultimately promotes cell EMT, invasion and metastasis in PCa.

Feasibility of Dose Escalating [18F]fluciclovine Positron Emission Tomography Positive Pelvic Lymph Nodes During Moderately Hypofractionated Radiation Therapy for High-Risk Prostate Cancer

Purpose

The aim of this study was to report the treatment planning feasibility of dose escalation to suspicious lymph nodes (LNs) for a series of men who underwent pretreatment [¹⁸F]fluciclovine positron emission tomography (PET)/magnetic resonance imaging (MRI).

Methods and Materials

Cases of men with prostate cancer who enrolled in a clinical trial of pretreatment [¹⁸F]fluciclovine PET who had suspicious LNs were selected. Pelvic LNs <1 cm were defined as positive based on [¹⁸F]fluciclovine-PET if their maximum standardized uptake value (SUV_max) was ≥1.3-fold greater than the reference blood pool SUV_mean, and LNs ≥1 cm were defined as positive if the SUV was greater than the reference SUV bone marrow reference. For each case, a radiation treatment plan was generated to deliver 70 Gy to the prostate and proximal seminal vesicles, 60.2 Gy to the PET-positive LNs, and 50.4 Gy to the elective nodal regions, simultaneously in 28 fractions of 2.5 Gy, 2.15 Gy, and 1.8 Gy, respectively. Treatment planning goals were defined a priori. The resulting target volume and organ-at-risk dosimetry were compared with the original treatment plan.

Results

Four cases were identified, with between 1 and 5 [¹⁸F]fluciclovine PET–positive LNs each. Goals for the prostate and elective nodal target volumes were successfully met in all cases. The goal of covering more than 90% of the positive LN planning target volume by the prescription dose of 60.2 Gy was met in 3 of the 4 cases. This goal was not met in 1 case, but 100% of clinical target volume was covered by 60.2 Gy. The primary organ-at-risk tradeoff was that a small volume (0.5-8.2 cm³) of small bowel would receive ≥54 Gy in each case.

Conclusions

These preliminary results suggest that [¹⁸F]fluciclovine PET/MRI directed dose escalation of suspicious pelvic LNs is likely feasible in the setting of definitive radiation therapy. The potential clinical benefit of dose escalating [¹⁸F]fluciclovine PET–positive LNs should be investigated in a prospective clinical trial.

Direct comparison of choline PET/CT and MRI in the diagnosis of lymph node metastases in patients with prostate cancer

BACKGROUND

Lymph node detection in prostate cancer is challenging and critical to determine treatment policy. Choline PET/CT (positron emission tomography/computed tomography) and magnetic resonance imaging (MRI) have been used for the evaluation of lymph node metastasis in patients with prostate cancer for the past decade. However, only limited patients underwent direct comparison studies.

PURPOSE

To evaluate the diagnostic performance of choline PET/CT compared with MRI imaging for detecting lymph node metastases in prostate cancer patients.

MATERIAL AND METHODS

Relevant English-language articles published before February 2018 were searched in PubMed database, Embase database, and Cochrane Library databases search using the keywords: (Prostate Neoplasm OR Prostate Cancer OR prostate carcinoma) and (Lymph Node) and (PET/CT OR positron emission tomography/computed tomography) and (choline or 2-hydroxy-N,N,N-trimethylethanaminium) and (magnetic resonance imaging OR MRI). Articles were included that directly compare the diagnostic performance and clinical utility of choline PET/CT and MRI for detecting lymph node metastases in prostate cancer patients. Study quality was assessed with QUADAS criteria. Analyses were performed on a per patient and a per node basis. The pooled sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (LR+), and negative likelihood ratio (LR-) were calculated using Meta-Disc 1.4 software. Summary receiver-operating characteristic (SROC) curves constructed.

RESULTS

A total of 362 patients from 8 studies involving fulfilled the inclusion criteria. On patient-based analysis, the pooled sensitivity, specificity, and DOR with a 95% confidence interval (CI) for choline PET/CT imaging were 0.59 (95%CI, 0.50-0.67), 0.92 (95%CI, 0.87-0.96), 17.37 (95%CI, 4.42-68.33), and for MRI imaging, they were 0.52 (95%CI, 0.44-0.61), 0.87 (95%CI, 0.81-0.92), 6.05 (95%CI, 3.09-11.85), respectively. On node-based, the corresponding values for choline PET/CT imaging were 0.51 (95%CI, 0.46-0.57), 0.99 (95%CI, 0.98-0.99), 65.55 (95%CI, 23.55-182.45), and for MRI imaging, they were 0.39 (95%CI, 0.34-0.44), 0.97 (95%CI, 0.96-0.97), 15.86 (95%CI, 8.96-28.05), respectively.

CONCLUSION

Choline PET/CT performed better than MRI imaging in evaluating the lymph nodes metastasis of prostate cancer patients and had the potential to be broadly applied in clinical practice.

Preoperative PET/CT 18F-FDG Standardized Uptake by Lymph Nodes as a Significant Prognostic Factor in Patients with Colorectal Cancer

Purpose

We evaluated the prognostic value of preoperative ¹⁸F-FDG uptake by suspected lymph nodes (LNs) using ¹⁸F-FDG PET/CT in colorectal cancer patients.

Methods

Patients with CRC underwent ¹⁸F-FDG PET/CT before radical surgery. We used Cox proportional hazards regression to examine the relationship between recurrence and the ¹⁸F-FDG maximum standardized uptake value (SUVmax) in the suspected LNs (SUV_LN) on ¹⁸F-FDG PET/CT.

Results

Clinical data, treatment modalities, and results from 90 CR C patients were reviewed. The median follow-up was 19 months (range 3 to 72 months). Receiver operating characteristic analysis identified SUV_LN 1.15 was the optimal cut-off value for predicting recurrence. SUV_LN correlated with tumour size (P=0.045), lymph node metastasis (P=0.03), and recurrence (P < 0.0001). Univariate analysis showed significant associations between recurrence and SUV_LN (P=0.017), and tumour grade (P=0.013). Multivariate analysis identified SUV_LN (P < 0.0001), and tumour grade (P=0.005) as independent risk factors for recurrence. Patients with SUV_LN ≤ 1.15 and SUV_LN > 0.15 differed significantly in terms of recurrence (P < 0.0001).

Conclusion

Preoperative SUV_LN measured by ¹⁸F-FDG PET/CT was significantly associated with recurrence and had significant prognostic value for recurrence-free survival in patients with colorectal cancer.

Developing a personalized template for lymph node dissection during radical prostatectomy

Lymph node dissection (LND) represents a critical step in order to determine lymph node invasion (LNI), not only for prognostic means but also as a therapeutic strategy in the management of patients with prostate cancer (CaP). Indications for performing LND are inconsistent with the American Urologic Association (AUA), European Association of Urology (EAU), and National Comprehensive Cancer Network (NCCN) recommendations differing. A thorough appreciation of lymph node drainage patterns and extent of LND has reshaped our understanding of this disease. Moreover, newer research into this field has directly resulted in refinements to current nomograms with utilization of various prostate-specific antigen (PSA) parameters and genomic medicine. Lastly, the application of newer imaging modalities in combination with molecular-guided robotic surgery has personalized the approach of LND espousing excellent safety, efficacy, and oncologic outcomes in these patients.

Clinical implications of PET/CT in prostate cancer management

Several imaging modalities exist for the investigation of prostate cancer (PCa). From ultrasound to computed tomography (CT) and magnetic resonance imaging (MRI), the role of imaging in detecting lesion foci, staging, and localizing disease after biochemical recurrence (BCR) is expanding. However, many of the conventional imaging modalities are suboptimal, particularly in the detection of metastasis. Positron emission tomography (PET) has recently emerged as a promising tool in PCa management. The ability to develop radiolabeled tracers for functional imaging based on characteristics of PCa cells can potentially provide more insight into management by utilizing key features of those cells, such as metabolic activity, increased proliferation, and receptor expression. 18-flurodeoxyglucose (FDG) is one of the earliest tracers used in PET imaging that takes advantage of increased metabolism of glucose. Its role in PCa has been somewhat limited due to poor resolution and confounders including noise resulting from the proximity of the prostate to the bladder. Choline, a precursor molecule for a major component of the cell membrane, phosphatidylcholine, shows increased uptake in cells with rapid proliferation. When compared to metabolic based imaging techniques with FDG, choline PET/CT was superior. Nevertheless, choline PET/CT was not equivocal to MRI in detection of local disease, but was superior to conventional imaging in localizing metastasis and lymph node metastasis (LNM). Fluciclovine is another novel marker that utilizes the increased proliferation seen in tumor cells. Studies have shown it to be superior to choline PET/CT in PCa management, particularly in patients with BCR. As with choline PET/CT, studies that have assessed the impact of fluciclovine on clinical practice have highlighted the impact of these new tracers on clinical decision making. Most recently, the newest molecular probe targeting prostate specific membrane antigen (PSMA) was developed. It offers higher detection rates compared to choline PET/CT and conventional imaging modalities and has shown promise in LNM and BCR. With the wide range of available PET tracers, this review aims to highlight the role of each in lesion foci detection, primary staging, disease recurrence and explore the potential clinical impact.