Current Clinical Applications of PSMA-PET for Prostate Cancer Diagnosis, Staging, and Treatment

Over the past decade, prostate-specific membrane antigen positron emission tomography (PSMA-PET) has revolutionized prostate cancer (PCa) imaging, offering greater sensitivity and specificity compared to conventional imaging modalities such as CT, MRI, and bone scintigraphy. PSMA-PET is particularly valuable in staging newly diagnosed patients with intermediate- and high-risk disease, detecting biochemical recurrence, and evaluating metastatic cases. By utilizing radiotracers that accumulate specifically in PSMA-expressing cells, even small metastases can be detected, offering a detailed assessment of cancer extent and enabling more targeted diagnostic evaluations. Among the most utilized radiotracers, [$^{68}$Ga]- and [$^{18}$F]-labeled PSMA tracers enable precise imaging even with low disease burden. This diagnostic precision also supports advanced therapeutic approaches, including metastasis-directed therapy for oligometastatic cases and systemic treatment options, such as radioligand therapy, which presents new treatment perspectives for metastatic, castration-resistant PCa. This review examines the evolution of PSMA-PET in the diagnostics and therapy of PCa while comparing the current recommendations from leading clinical guidelines. The integration of PSMA-PET into clinical practice has redefined the management of PCa, improving diagnostic accuracy and enabling personalized treatment strategies, while lacking prospective long-term outcome data. As PSMA-PET continues to expand in clinical application, this review highlights its significant advancements while critically addressing limitations to ensure balanced and evidence-based implementation in prostate cancer care

Retrospective analysis of the uptake of active surveillance for low-risk prostate cancer in Zurich, Switzerland

OBJECTIVES Active surveillance for low-risk prostate cancer closely monitors patients conservatively instead of the pursuit of active treatment to reduce overtreatment of insignificant disease. Since 2009, active surveillance has been recommended as the primary management option in the European Association of Urology guidelines for low-risk disease. The present study aimed to investigate the use and uptake of active surveillance over 10 years in our certified prostate cancer centre (University Hospital of Zurich) compared with those derived from the cancer registry of the canton of Zurich, Switzerland. MATERIALS AND METHODS We retrospectively identified all men diagnosed with low-risk prostate cancer at our institution and from the cancer registry of the canton of Zurich from 2009 to 2018. The primary treatment of each patient was recorded. Descriptive statistics were used to analyze the use of different treatments in our centre. The results were compared with those derived from the cancer registry. RESULTS A total of 3393 men with low-risk prostate cancer were included in this study (University Hospital of Zurich: n = 262; cancer registry: n = 3131). In the University Hospital of Zurich and cancer registry cohorts, 146 (55.7%) and 502 (16%) men underwent active surveillance, respectively. The proportions of local treatment [115 (43.9%) vs 2220 (71%)] and androgen deprivation therapy [0 (0%) vs 43 (1.4%)] were distinctly lower in the University Hospital of Zurich cohort than in the cancer registry cohort. The uptake of active surveillance over the years was high in the University Hospital of Zurich cohort (35.4% in 2009 and 88.2% in 2018) but only marginal in the cancer registry cohort (12.2% in 2009 and 16.2% in 2018). CONCLUSION Despite clear guideline recommendations, active surveillance for low-risk prostate cancer is still widely underused. Our analysis showed that access to a certified interdisciplinary tumour board significantly increases the use of active surveillance

Prognostic value of pretreatment inflammatory markers in localised prostate cancer before radical prostatectomy

PURPOSE There is growing evidence of an association between inflammatory processes and cancer development and progression. In different solid tumor entities, a pronounced inflammatory response is associated with worse oncological outcome. In this study, we aim to evaluate the prognostic role of clinically established pretreatment inflammatory markers in patients with localised prostate cancer (PCa) before radical prostatectomy (RP). METHODS A total of 641 men met our inclusion criteria and were followed prospectively for a median of 2.85 years. Univariable logistic and Cox regression analysis were performed to analyse associations between preoperative inflammatory markers and tumor characteristics, and biochemical recurrence free survival (BRFS). RESULTS Median age at RP was 64 years. Gleason Score (GS) 7a (263, 41%) was the most prevalent histology, whereas high-risk PCa (≥ GS 8) was present in 156 (24%) patients. Lympho-nodal metastasis and positive surgical margin (PSM) were detected in 69 (11%) and 180 (28%) patients, respectively. No statistically relevant association could be shown between pretreatment inflammatory markers with worse pathological features like higher tumor stage or grade, nodal positive disease or PSM (for all p > 0.05). Additionally, pretreatment inflammatory markers were not associated with a shorter BRFS (p > 0.05). Known risk factors (tumor grade, tumor stage, nodal positivity and positive surgical margins) were all associated with a shorter BRFS (for all p < 0.0001). CONCLUSION In this large prospective cohort, preoperative inflammatory markers were not associated with worse outcome

Effect of Propofol Versus Sevoflurane on Erections during Narcosis in Transurethral Surgery: The PENIS Trial

Penile erection is unwanted during transurethral interventions as it may be associated with adverse events such as impaired access, prolonged operation time, abortion of the procedure, or a need for ancillary measures to reach penis flaccidity, such as intracorporeal injection of vasoactive drugs. In recent years, anesthesia with propofol has been favored over sevoflurane for environmental reasons. To the best of our knowledge, there have been no prospective randomized clinical trials evaluating the impact of general narcosis medications on the risk of such unwanted penile erections during transurethral surgery. To fill this gap, we have planned a prospective, double-blind (surgeon and patient), single-center, randomized controlled trial. The primary outcome is the occurrence of an intraoperative penile erection. The secondary outcomes are related to the impact of the primary outcome on the surgery, such as changes in operative strategy or operation duration, abortion of the procedure, and adverse events. The plan is to randomize 200 patients undergoing transurethral surgery to receive general anesthesia with either propofol or sevoflurane. The inclusion criteria are men aged <75 yr with an International Index of Erectile Function-5 score of ≥12 points. All men fulfilling the inclusion criteria will be asked to participate. Exclusion criteria are patient characteristics associated with a higher risk of complications with the use of either propofol or sevoflurane. Randomization and treatment allocation will occur after patients give consent. The results will be statistically analyzed using a logistic regression model. This research has received ethical clearance from the local ethics committee (KEK code 2023-01682). The trial is registered on the Swiss National Clinical Trials Portal (SNCTP000005681) and on ClinicalTrial.gov (NCT06378645)

External Validation and Comparison of Prostate Cancer Risk Calculators Incorporating Multiparametric Magnetic Resonance Imaging for Prediction of Clinically Significant Prostate Cancer

PURPOSE: To externally validate recently published prostate cancer risk calculators (PCa-RCs) incorporating multiparametric magnetic resonance imaging (mpMRI) for the prediction of clinically significant prostate cancer (csPCa) and compare their performance to mpMRI-naïve PCa-RCs. MATERIAL AND METHODS: Men without previous PCa diagnosis undergoing transperineal template saturation prostate biopsy with fusion-guided targeted biopsy between 11/2014 and 03/2018 in our academic tertiary referral center were identified. Any Gleason pattern ≥4 was defined to be csPCa. Predictors (age, PSA, DRE, prostate volume, family history, previous prostate biopsy and highest region of interest according to PIRADS) were retrospectively collected. Four mpMRI-PCa-RCs and two mpMRI-naïve PCa-RCs were evaluated for their discrimination, calibration and clinical net benefit using a ROC analysis, calibration plots and a decision curve analysis, respectively. RESULTS: Out of 468 men, 193 (41%) were diagnosed with csPCa. Three mpMRI-PCa-RCs showed similar discrimination with area-underneath-the-receiver-operating-characteristic-curves (AUC) from 0.83 to 0.85, which was significantly higher than the other PCa-RCs (AUCs: 0.69-0.74). Calibration-in-the-large showed minimal deviation from the true amount of csPCa by 2% for two mpMRI-PCa-RCs, while the other PCa-RCs showed worse calibration (11-27%). A clinical net benefit could only be observed for three mpMRI-PCa-RCs at biopsy thresholds ≥15%, while none of the six investigated PCa-RCs demonstrated clinical utility against a biopsy all strategy at thresholds <15%. CONCLUSIONS: Performance of the mpMRI-PCa-RCs varies, but they generally outperform mpMRI-naïve PCa-RCs in regard to discrimination, calibration and clinical usefulness. External validation in other biopsy settings is highly encouraged

Prospective observational study of the role of the microbiome in BCG responsiveness prediction (SILENT-EMPIRE): a study protocol

INTRODUCTION The human microbiota, the community of micro-organisms in different cavities, has been increasingly linked with inflammatory and neoplastic diseases. While investigation into the gut microbiome has been robust, the urinary microbiome has only recently been described. Investigation into the relationship between bladder cancer (BC) and the bladder and the intestinal microbiome may elucidate a pathophysiological relationship between the two. The bladder or the intestinal microbiome or the interplay between both may also act as a non-invasive biomarker for tumour behaviour. While these associations have not yet been fully investigated, urologists have been manipulating the bladder microbiome for treatment of BC for more than 40 years, treating high grade non-muscle invasive BC (NMIBC) with intravesical BCG immunotherapy. Neither the association between the microbiome sampled directly from bladder tissue and the response to BCG-therapy nor the association between response to BCG-therapy with the faecal microbiome has been studied until now. A prognostic tool prior to initiation of BCG-therapy is still needed. METHODS AND ANALYSIS In patients with NMIBC bladder samples will be collected during surgery (bladder microbiome assessment), faecal samples (microbiome assessment), instrumented urine and blood samples (biobank) will also be taken. We will analyse the microbial community by 16S rDNA gene amplicon sequencing. The difference in alpha diversity (diversity of species within each sample) and beta diversity (change in species diversity) between BCG-candidates will be assessed. Subgroup analysis will be performed which will lead to the development of a clinical prediction model estimating risk of BCG-response. ETHICS AND DISSEMINATION The study has been approved by the Cantonal Ethics Committee Zurich (2021-01783) and it is being conducted in accordance with the Declaration of Helsinki and Good Clinical Practice. Study results will be disseminated through peer-reviewed journals and national and international scientific conferences. TRIAL REGISTRATION NUMBER NCT05204199

Immunohistochemical ERG positivity is associated with decreased PSMA expression and lower visibility in corresponding [68^{68}Ga]Ga-PSMA-11 PET scans of primary prostate cancer

PURPOSE: TMPRSS2:ERG gene fusion negatively regulates PSMA expression in prostate adenocarcinoma (PCa) cell lines. Therefore, immunohistochemical (IHC) ERG expression, a surrogate for an underlying ERG rearrangement, and PSMA expression patterns in radical prostatectomy (RPE) specimens of primary PCa, including corresponding PSMA-PET scans were investigated. METHODS: Two cohorts of RPE samples (total n=148): In cohort #1 (n=62 patients) with available RPE and preoperative [$^{68}$Ga]Ga-PSMA-11 PET, WHO/ISUP grade groups, IHC-ERG (positive vs. negative) and IHC-PSMA expression (% PSMA-negative tumour area, PSMA$_{\%neg}$) were correlated with the corresponding SUV$_{max}$. In the second cohort #2 (n=86 patients) including RPE only, same histopathological parameters were evaluated. RESULTS: Cohort #1: PCa with IHC-ERG expression (35.5%) showed significantly lower IHC-PSMA expression and lower SUV$_{max}$ values on the corresponding PET scans. Eight of 9 PCa with negative PSMA-PET scans had IHC-ERG positivity, and confirmed TMPRSS2::ERG rearrangement. In IHC-PSMA positive PCa, IHC-ERG positivity was significantly associated with lower SUV$_{max}$ values. In cohort #2, findings of higher IHC-PSMA$_{\%neg}$ and IHC-ERG expression was confirmed with only 0-10% PSMA$_{\%neg}$ tumour areas in IHC-ERG-negative PCa. CONCLUSION: IHC-ERG expression is significantly associated with more heterogeneous and lower IHC-PSMA tissue expression in two independent RPE cohorts. There is a strong association of ERG positivity in RPE tissue with lower [$^{68}$Ga]Ga-PSMA-11 uptake on corresponding PET scans. Results may serve as a base for future biomarker development to enable tumour-tailored, individualized imaging approaches

Instrumental dead space and proximal working channel connector design in flexible ureteroscopy: a new concept

OBJECTIVE The objective of this study was to evaluate a new concept in flexible ureteroscopy: instrumental dead space (IDS). For this purpose, various proximal working channel connector designs, as well as the impact of ancillary devices occupying the working channel were evaluated in currently available flexible ureteroscopes. DESIGN AND METHODS IDS was defined as the volume of saline irrigation needed to inject at the proximal connector for delivery at the distal working channel tip. Because IDS is related to working channel diameter and length, proximal connector design, as well as occupation of working channel by ancillary devices, these parameters were also reviewed. RESULTS IDS significantly varied between flexible ureteroscope models, ranging from 1.1 ml for the Pusen bare scopes, to 2.3 ml for Olympus scopes with their 4-way connector (p < 0.001). Proximal connector designs showed a high degree of variability in the number of available Luer locks, valves, seals, angles, and rotative characteristics. The measured length of the working channel of bare scopes ranged between 739 and 854 mm and significantly correlated with measured IDS (R$^{2}$ = 0.82, p < 0.001). The coupling of scopes with an alternative ancillary proximal connector and the insertion of ancillary devices into the working channel significantly reduced IDS (mean IDS reduction of 0.1 to 0.5 ml; p < 0.001). CONCLUSIONS IDS appears as a new parameter that should be considered for future applications of flexible ureteroscopes. A low IDS seems desirable for several clinical applications. The main factors impacting IDS are working channel and proximal connector design, as well as ancillary devices inserted into the working channel. Future studies should clarify how reducing IDS may affect irrigation flow, intrarenal pressure, and direct in-scope suction, as well as evaluate the most desirable proximal connector design properties

Illumination matters part IV: blackout and whiteout in flexible ureteroscopy - first report on a phenomenon observed by PEARLS

PURPOSE: To date, no study has evaluated effects of varying brightness settings on image quality from flexible ureteroscopes submerged in saline. The aim was to evaluate blackout and whiteout occurrences in an in-vitro kidney calyx model. MATERIAL AND METHODS: We evaluated a series of contemporary flexible ureteroscopes including the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, as well as OTU WiScope using a 3D-printed enclosed pink in-vitro kidney calyx model submerged in saline. Endoscopic images were captured with ureteroscope tip placed at 5 mm,10 mm and 20 mm distances. The complete range of brightness settings and video capture modes were evaluated for each scope. Distribution of brightness on a grayscale histogram of images was analyzed (scale range 0 to 255). Blackout and whiteout were defined as median histogram ranges from 0 to 35 and 220 to 255, respectively (monitor image too dark or too bright for the human eye, respectively). RESULTS: Blackout occurred with the P7, Pusen 7.5F, 9.2F and WiScope at all distances, and V3 at 20 mm - with lowest brightness settings. Whiteout occurred with Flex-X2s, V3 and P7 at 5 mm and 10 mm, as well as with V3 and P7 at 20 mm - mostly with highest brightness settings. The Flex-Xc had neither blackout nor whiteout at all settings and distances. CONCLUSION: Blackout or whiteout of images is an undesirable property that was found for several scopes, possibly impacting diagnostic and therapeutic purposes during ureteroscopy. These observations form a guide to impact a urologist's choice of instruments and settings