Near-infrared fluorescence lymph node template region dissection plus backup lymphadenectomy in open radical cystectomy for bladder cancer using an innovative handheld device: A single center experience.

BACKGROUND: The extent of pelvic lymphadenectomy (PLND) as part of radical cystectomy (RC) for bladder cancer (BC) remains unclear. Sentinel-based and lymphangiographic approaches could lead to reduced morbidity without sacrificing oncologic safety. OBJECTIVE: To evaluate the feasibility and diagnostic value of fluorescence-guided template sentinel region dissection (FTD) using a handheld near-infrared fluorescence (NIRF) camera in open radical cystectomy. DESIGN, SETTING, AND PARTICIPANTS: After peritumoral cystoscopic injection of indocyanine green (ICG) 21 patients underwent open RC with FTD due to BC between June 2019 and June 2021. Intraoperatively, the FIS-00 Hamamatsu Photonics® NIRF camera was used to identify and resect fluorescent template sentinel regions (FTRs) followed by extended pelvic lymphadenectomy (ePLND) as oncological back-up. OUTCOME MEASUREMENT AND STATISTICAL ANALYSIS: Descriptive analysis of positive and negative results per template region. RESULTS AND LIMITATIONS: FTRs were identified in all 21 cases. Median time (range) from ICG injection to fluorescence detection was 75 (55-125) minutes. On average (SD), 33.4 (9.6) lymph nodes were dissected per patient. Considering template regions as the basis of analysis, 67 (38.3%) of 175 resected regions were NIRF-positive, with 13 (7.4%) regions harboring lymph node metastases. We found no metastatic lymph nodes in NIRF-negative template regions. Outside the standard template, two NIRF-positive benign nodes were identified. CONCLUSION: The concept of NIRF-guided FTD proved for this group all lymph node metastases to be found in NIRF-positive template regions. Pending validation in a larger collective, resection of approximately 40% of standard regions may be sufficient and may result in less morbidity.

Retrograde Pyelography in the Presence of Urothelial Bladder Cancer Does Not Affect the Risk of Upper Tract Urothelial Cancer: A Retrospective Analysis of a Single-Centre Cohort.

OBJECTIVE: Patients with bladder cancer (BC) are at risk of developing upper tract urothelial carcinoma (UTUC). Therefore, CT urography is recommended for follow-up. To avoid intravenous contrast agents, retrograde pyelography (RPG) is an alternative. However, it is still unclear whether RPG increases the incidence of UTUC. The aim of this study was to investigate the impact of RPG in the presence of BC on the risk of developing UTUC. PATIENTS AND METHODS: Retrospectively analysing a total of 3,680 RPGs between 2009 and 2016, all patients with simultaneous BC (group 1) and those without synchronous BC (group 2) during RPG were compared. All patients were risk stratified according to the EORTC bladder calculator. In patients without BC during RPG, risk stratification was based on the worst prior tumour characteristics. RESULTS: A total of 145 patients with a history of BC were analysed. Of these, 112 patients underwent RPG with simultaneous BC. UTUC developed in 6 of 112 patients (5.4%) and 58.9% (66/112) had high-risk BC according to the EORTC bladder calculator. In the control group, one out of 33 (3%) patients with metachronous high-risk BC developed UTUC. CONCLUSIONS: Using RPG in the presence of BC did not increase the risk of UTUC. Due to the predominant number of high-risk/high-grade tumours, individual tumour biology appears to be the primary driver for the development of UTUC.

Comprehensive analysis of serum chromogranin A and neuron-specific enolase levels in localized and castration-resistant prostate cancer.

OBJECTIVES: To assess chromogranin A (CGA) and neuron-specific enolase (NSE) levels and changes in these at different stages of prostatic adenocarcinoma (PCA). METHODS: Overall, 1095 serum samples from 395 patients, divided into three treatment groups, were analysed; the radical prostatectomy (RP) cohort (n = 157) included patients with clinically localized PCA, while the docetaxel (DOC) and the abiraterone (ABI)/enzalutamide (ENZA) cohorts included 95 and 143 patients, respectively, with metastatic castration-resistant prostate cancer. CGA, NSE and total PSA levels were measured using the KRYPTOR method. RESULTS: Baseline CGA and NSE levels were higher in castration-resistant (DOC and ABI/ENZA cohorts) than in hormone-naïve, clinically localized PCA (P < 0.001). High baseline CGA levels were independently associated with poor overall survival in both the DOC and the ABI/ENZA cohorts, with a stronger association in the ABI/ENZA cohort. In the ABI/ENZA cohort, a > 50% CGA increase at 3 months was associated with poor survival, especially in patients with high baseline CGA levels. CONCLUSIONS: The two- to threefold higher neuroendocrine marker levels in castration-resistant compared to hormone-naïve PCA support the presence of neuroendocrine transdifferentiation under androgen deprivation therapy. Our results showed patients with high baseline CGA levels who experienced a further CGA increase during ABI and ENZA treatment had the poorest prognosis. Serum CGA levels could help in tailoring and monitoring therapy in advanced PCA.

External validation of novel magnetic resonance imaging-based models for prostate cancer prediction.

OBJECTIVES: To validate, in an external cohort, three novel risk models, including the recently updated European Randomized Study of Screening for Prostate Cancer (ERSPC) risk calculator, that combine multiparametric magnetic resonance imaging (mpMRI) and clinical variables to predict clinically significant prostate cancer (PCa). PATIENTS AND METHODS: We retrospectively analysed 307 men who underwent mpMRI prior to transperineal ultrasound fusion biopsy between October 2015 and July 2018 at two German centres. mpMRI was rated by Prostate Imaging Reporting and Data System (PI-RADS) v2.0 and clinically significant PCa was defined as International Society of Urological Pathology Gleason grade group ≥2. The prediction performance of the three models (MRI-ERSPC-3/4, and two risk models published by Radtke et al. and Distler et al., ModRad and ModDis) were compared using receiver-operating characteristic (ROC) curve analyses, with area under the ROC curve (AUC), calibration curve analyses and decision curves used to assess net benefit. RESULTS: The AUCs of the three novel models (MRI-ERSPC-3/4, ModRad and ModDis) were 0.82, 0.85 and 0.83, respectively. Calibration curve analyses showed the best intercept for MRI-ERSPC-3 and -4 of 0.35 and 0.76. Net benefit analyses indicated clear benefit of the MRI-ERSPC-3/4 risk models compared with the other two validated models. The MRI-ERSPC-3/4 risk models demonstrated a discrimination benefit for a risk threshold of up to 15% for clinically significant PCa as compared to the other risk models. CONCLUSION: In our external validation of three novel prostate cancer risk models, which incorporate mpMRI findings, a head-to-head comparison indicated that the MRI-ERSPC-3/4 risk model in particular could help to reduce unnecessary biopsies.

Circulating and tissue IMP3 levels are correlated with poor survival in renal cell carcinoma.

Tissue protein expression of IMP3 is emerging as a promising prognostic factor in renal cell carcinoma (RCC). The most commonly used immunohistochemical (IHC) antibody has been criticized for its low specificity. In addition, blood levels of IMP3 have not yet been analyzed in RCC. Therefore, we compared the prognostic performance of two different IMP3 IHC antibodies and assessed the prognostic relevance of IMP3 plasma levels in RCC. IMP3 levels were assessed in an overall number of 425 RCC (344× clear cell [ccRCC], 63× papillary [pRCC], 18× chromophobe [chRCC]) patients in three partly overlapping cohorts. Plasma IMP3 concentrations were determined by ELISA in 98 RCC (79× ccRCC, 15× pRCC, 4× chRCC) patients and 20 controls. IMP3 mRNA expression levels were analyzed in 73 frozen tissue samples (55× ccRCC, 12× pRCC, 6× chRCC), while protein expressions were assessed in 366 FFPE samples (294× ccRCC, 56× pRCC, 16× chRCC) using the M3626 and N-19 antibodies. IMP3 plasma and mRNA expression levels were significantly higher in patients compared to controls and in high-grade compared to low-grade tumors. In addition, IMP3 plasma and tissue protein levels (by M3626) were higher and IMP3 mRNA expression levels tended to be higher in patients with distant metastasis. Multivariate analyses in clear cell RCC revealed high IMP3 plasma concentration and mRNA expression as independent predictors of disease-specific survival. IMP3 immunostainings by M3626 but not by N-19 were independently associated with poor overall and disease-specific survival. High plasma and tissue levels of IMP3 are independently associated with poor RCC prognosis. The applied antibody significantly impacts the prognostic performance of analysis. IMP3 analysis may improve risk-stratification of RCC patients and therefore could help to optimize therapeutic and follow-up decisions.

The current role of pentafecta in the reporting of radical cystectomy outcomes: a scoping review.

Background: Pentafecta has recently been validated for reporting radical cystectomy (RC) outcomes in open, laparoscopic and robotic series. We aim in this review to explore the current role of pentafecta in the reporting of RC outcomes. Methods: A comprehensive literature search was performed in the PubMed database to identify relevant articles. The pentafecta achievement (PA) was defined originally as negative soft tissue surgical margin (NSTSM), lymph node (LN) dissection (LND) with removal of ≥16 LNs, absence of 90-days grade ≥3 Clavien-Dindo (CD) complications, a time interval of less than 3 months between the last transurethral resection of bladder tumor (TURBT) with evidence of muscle invasive bladder cancer (MIBC) and RC, and absence of local pelvic recurrence within 1 year. The definition was later modified and the last two criteria were replaced by absence of urinary diversion (UD) related complications and any clinical recurrence at one year. Results: Twelve studies with 4,946 patients were enrolled in the present review. All the studies were retrospective except one recently published randomized study comparing open and robotic-assisted RC. Pentafecta was totally achieved in 34% and main causes of missing pentafecta were the number of resected LNs and 90-days major complications. Type of UD, increasing age, advanced tumor stage, and decreasing surgical experience were the factors most commonly associated with a lower likelihood of PA. A positive correlation was seen between PA and long-term oncological outcome and quality of life. The main limitations in the present studies are their retrospective nature, relatively small sample size, and short median follow-up, most of which was less than 3 years. Conclusions: The new pentafecta definition provides a comprehensive tool for reporting RC outcomes by including measures of postoperative morbidity, functional outcomes and local cancer control. Pentafecta include standards that could be useful for improving surgical quality, surgical education and comparing different techniques. However, pentafecta is not yet suitable for perioperative risk stratification and patient counseling.

The impact of double-J ureteral stenting before radical cystectomy on the development of upper tract urothelial carcinoma.

BACKGROUND: It is controversial whether the use of a double-J stent (DJ) in patients with bladder cancer before radical cystectomy (RC) increases the risk of tumour seeding in the upper tract and thus the risk of metachronous upper tract urothelial carcinoma (UTUC). The aim of our study is to investigate the risk of upper tract recurrence after RC in patients previously managed with a DJ stent. METHODS: A total of 699 patients who had undergone RC between January 2003 and March 2022 with complete perioperative data and pathological outcome were included in our study. Patients treated preoperatively with a DJ stent were identified and compared for development of metachronous UTUC with those who did not receive prior internal stenting. Multivariable Cox regression analysis was used to determine predictors of UTUC occurrence among the possible pathological features; risk factors for mortality after RC were also examined. RESULTS: Of 699 patients, 117 (16.7%) were managed preoperatively with a DJ stent. The overall probability of metachronous UTUC was 1%, 4% and 6% at 1, 3 and 5 years, respectively. The groups with and without DJ stenting were comparable regarding their clinicopathologic features, except for the higher incidence of hydronephrosis in the DJ group. At similar follow-up periods (median follow-up 32 months), metachronous UTUC was detected in four (3.4%) patients in the DJ group and in 13 (2.2%) in the non-stented group (P=0.44). The median interval (IQR) from cystectomy to UTUC was 40.5 (20-49) months in the DJ group and 37 (24-82) in the non-stented group (P=0.7). In the multivariable analysis, only presence of CIS (HR 3.83, 95% CI 1.19-12.29, P=0.024) and positive ureteral margin (HR=5.2, 95% CI 1.38-19.57, P=0.015) were predictors of metachronous UTUC. The study is limited by the retrospective nature and relatively short follow-up. CONCLUSIONS: Ureteral stenting for management of hydronephrosis in patients with bladder cancer undergoing RC is a viable option, without higher risk for UTUC or mortality. Patients with positive ureteral margin and CIS are considered high-risk groups for upper tract recurrence and should receive long-term, rigorous follow-up.

Cumulative sum analysis (CUSUM) for evaluating learning curve (LC) of robotic-assisted laparoscopic partial nephrectomy (RALPN).

Robotic-assisted laparoscopic partial nephrectomy (RALPN) is becoming a standard treatment for localized renal tumors worldwide. Data on the learning curve (LC) of RALPN are still insufficient. In the present study, we have attempted to gain further insight in this area by evaluating the LC using cumulative summation analysis (CUSUM). A series of 127 robotic partial nephrectomies were performed by two surgeons at our center between January 2018 and December 2020. CUSUM analysis was used to evaluate LC for operative time (OT). The different phases of surgical experience were compared in terms of perioperative parameters and pathologic outcomes. In addition, multivariate linear regression analysis was used to confirm the results of the CUSUM analysis by adjusting the phases of surgical experience for the other confounding factors that may affect OT. The median age of patients was 62 years, mean BMI was 28, and mean tumor size was 32 mm. Tumor complexity was classified as low, intermediate, and high risk according to the PADUA score in 44%, 38%, and 18%, respectively. The mean OT was 205 min, and trifecta was achieved in 72.4%. According to the CUSUM diagram, the LC of OT was divided into three phases: initial learning phase (18 cases), plateau phase (20 cases), and mastery phase (subsequent cases). The mean OT was 242, 208, and 190 min in the first, second, and third phases, respectively (P < 0.001). Surgeon experience phases were significantly associated with OT in multivariate analysis considering other preoperative and operative parameters. Surgical outcome was comparable between the three phases in terms of complications and achievement of trifecta; hospital stay was shorter in the mastery phase than in the first 2 phases (4 days vs 5 days, P = 0.02). The LC for RALPN is divided into 3 performance phases with CUSUM. Mastery of surgical technique was achieved after performing 38 cases. The initial learning phase of RALPN has no negative impact on surgical and oncologic outcomes .

18F-PSMA Cerenkov Luminescence and Flexible Autoradiography Imaging in a Prostate Cancer Mouse Model and First Results of a Radical Prostatectomy Feasibility Study in Men.

Intraoperative identification of positive resection margins (PRMs) in high-risk prostate cancer (PC) needs improvement. Cerenkov luminescence imaging (CLI) with 68Ga-PSMA-11 is promising, although limited by low residual activity and artificial signals. Here, we aimed to assess the value of CLI and flexible autoradiography (FAR) with 18F-PSMA-1007. Methods: Mice bearing subcutaneous PSMA-avid RM1-PGLS tumors were administered 18F-PSMA-1007, and PET/CT was performed. After the animals had been killed, organs were excised and measured signals in CLI and FAR CLI were correlated with tracer activity concentrations (ACs) obtained from PET/CT. For clinical assessment, 7 high-risk PC patients underwent radical prostatectomy immediately after preoperative 18F-PSMA PET/CT. Contrast-to-noise ratios (CNRs) were calculated for both imaging modalities in intact specimens and after incision above the index lesion. Results: In the heterotopic in vivo mouse model (n = 5), CLI did not detect any lesion. FAR CLI detected a distinct signal in all mice, with a lowest AC of 7.25 kBq/mL (CNR, 5.48). After incision above the index lesion of the prostate specimen, no increased signal was observed at the cancer area in CLI. In contrast, using FAR CLI, a signal was detectable in 6 of 7 patients. The AC in the missed index lesion was 1.85 kBq/mL, resulting in a detection limit of at least 2.06 kBq/mL. Histopathology demonstrated 2 PRMs, neither of which was predicted by CLI or FAR CLI. Conclusion: 18F-PSMA FAR CLI was superior to CLI in tracer-related signal detectability. PC was could be visualized in radical prostatectomy down to 2.06 kBq/mL. However, the detection of PRMs was limited. Direct anatomic correlation of FAR CLI is challenging because of the scintillator overlay.

Detection of Clinically Significant Prostate Cancer Using Targeted Biopsy with Four Cores Versus Target Saturation Biopsy with Nine Cores in Transperineal Prostate Fusion Biopsy: A Prospective Randomized Trial.

BACKGROUND: Multiparametric magnetic resonance imaging (mpMRI) and targeted biopsy (TB) facilitate accurate detection of clinically significant prostate cancer (csPC). However, it remains unclear how targeted cores should be applied for accurate diagnosis of csPC. OBJECTIVE: To assess csPC detection rates for two target-directed MRI/transrectal ultrasonography (TRUS) fusion biopsy approaches, conventional TB and target saturation biopsy (TS). DESIGN, SETTING, AND PARTICIPANTS: This was a prospective single-center study of outcomes for transperineal MRI/TRUS fusion biopsies for 170 men. Half of the men (n = 85) were randomized to conventional TB with four cores per lesion and half (n = 85) to TS with nine cores. Biopsies were performed by three experienced board-certified urologists. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: PC and csPC (International Society of Urological Pathology grade group ≥2) detection rates for systematic biopsy (SB), TB, and TS were analyzed using McNemar's test for intrapatient comparisons and Fisher's exact test for TS versus TB. A combination of targeted biopsy (TS or TB) and SB served as the reference. RESULTS AND LIMITATIONS: According to the reference, csPC was diagnosed for 57 men in the TS group and 36 men in the TB group. Of these, TS detected 57/57 csPC cases and TB detected 33/36 csPC cases (p = 0.058). Detection of Gleason grade group 1 disease was 10/12 cases with TS and 8/17 cases with TB (p = 0.055). In addition, TS detected 97% of 63 csPC lesions, compared to 86% with TB (p = 0.1). Limitations include the single-center design, the limited generalizability owing to the transperineal biopsy route, the lack of central review of pathology and radical prostatectomy correlation, and uneven distributions of csPC prevalence, Prostate Imaging-Reporting and Data System (PI-RADS) 5 lesions, men with two or more PI-RADS ≥3 lesions, and prostate-specific antigen density between the groups, which may have affected the results. CONCLUSIONS: In our study, rates of csPC detection did not significantly differ between TS and TB. PATIENT SUMMARY: In this study, we investigated two targeted approaches for taking prostate biopsy samples after observation of suspicious lesions on prostate scans. We found that the rates of detection of prostate cancer did not significantly differ between the two approaches.

Radiation Protection and Occupational Exposure on 68Ga-PSMA-11-Based Cerenkov Luminescence Imaging Procedures in Robot-Assisted Prostatectomy.

Cerenkov luminescence imaging (CLI) was successfully implemented in the intraoperative context as a form of radioguided cancer surgery, showing promise in the detection of surgical margins during robot-assisted radical prostatectomy. The present study was designed to provide a quantitative description of the occupational radiation exposure of surgery and histopathology personnel from CLI-guided robot-assisted radical prostatectomy after the injection of 68Ga-PSMA-11 in a single-injection PET/CT CLI protocol. Methods: Ten patients with preoperative 68Ga-PSMA-11 administration and intraoperative CLI were included. Patient dose rate was measured before PET/CT (n = 10) and after PET/CT (n = 5) at a 1-m distance for 4 patient regions (head [A], right side [B], left side [C], and feet [D]). Electronic personal dosimetry (EPD) was used for intraoperative occupational exposure (n = 10). Measurements included the first surgical assistant and scrub nurse at the operating table and the CLI imager/surgeon at the robotic console and encompassed the whole duration of surgery and CLI image acquisition. An estimation of the exposure of histopathology personnel was performed by measuring prostate specimens (n = 8) with a germanium detector. Results: The measured dose rate value before PET/CT was 5.3 ± 0.9 (average ± SD) µSv/h. This value corresponds to a patient-specific dose rate constant for positions B and C of 0.047 µSv/h⋅MBq. The average dose rate value after PET/CT was 1.04 ± 1.00 µSv/h. The patient-specific dose rate constant values corresponding to regions A to D were 0.011, 0.026, 0.024, and 0.003 µSv/h⋅MBq, respectively. EPD readings revealed average personal equivalent doses of 9.0 ± 7.1, 3.3 ± 3.9, and 0.7 ± 0.7 µSv for the first surgical assistant, scrub nurse, and CLI imager/surgeon, respectively. The median germanium detector-measured activity of the prostate specimen was 2.96 kBq (interquartile range, 2.23-7.65 kBq). Conclusion: Single-injection 68Ga-PSMA-11 PET/CT CLI procedures are associated with a reasonable occupational exposure level, if kept under 110 procedures per year. Excised prostate specimen radionuclide content was below the exemption level for 68Ga. Dose rate-based calculations provide a robust estimation for EPD measurements.

[Local and metastasis-directed therapy for oligometastatic prostate cancer]. / Lokale und Metastasen -gerichtete Therapieoptionen beim oligometastasierten Prostatakarzinom.

New developments of systemic therapy concepts for metastatic prostate carcinoma have led to a significant improvement in the prognosis in the recent past. It has long been unclear to what extent local and/or metastasis-directed therapies have an additional oncologic benefit in addition to palliation, local control and functional maintenance. For local therapy of the prostate, the highest evidence currently exists for radiotherapy and shows a significantly increased overall survival in "low- burden" oligometastatic patients. Metastasis-directed surgical or radio-oncological concepts may also improve prognosis but have not yet been sufficiently investigated and should therefore be discussed, documented and established on an individual and interdisciplinary basis.

Detection of Significant Prostate Cancer Using Target Saturation in Transperineal Magnetic Resonance Imaging/Transrectal Ultrasonography-fusion Biopsy.

BACKGROUND: Multiparametric magnetic resonance imaging (mpMRI) and targeted biopsies (TBs) facilitate accurate detection of significant prostate cancer (sPC). However, it remains unclear how many cores should be applied per target. OBJECTIVE: To assess sPC detection rates of two different target-dependent magnetic resonance imaging (MRI)/transrectal ultrasonography (TRUS)-fusion biopsy approaches (TB and target saturation [TS]) compared with extended systematic biopsies (SBs). DESIGN, SETTING, AND PARTICIPANTS: Retrospective single-centre outcome of transperineal MRI/TRUS-fusion biopsies of 213 men was evaluated. All men underwent TB with a median of four cores per MRI lesion, followed by a median of 24 SBs, performed by experienced urologists. Cancer and sPC (International Society of Urological Pathology grade group ≥2) detection rates were analysed. TB was compared with SB and TS, with nine cores per target, calculated by the Ginsburg scheme and using individual cores of the lesion and its "penumbra". OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Cancer detection rates were calculated for TS, TB, and SB at both lesion and patient level. Combination of SB + TB served as a reference. Statistical differences in prostate cancer (PC) detection between groups were calculated using McNemar's tests with confidence intervals. RESULTS AND LIMITATIONS: TS detected 99% of 134 sPC lesions, which was significantly higher than the detection by TB (87%, p = 0.001) and SB (82%, p < 0.001). SB detected significantly more of the 72 low-risk PC lesions than TB (99% vs 68%, p < 0.001) and 10% (p = 0.15) more than that detected by TS. At a per-patient level, 99% of men harbouring sPC were detected by TS. This was significantly higher than that by TB and SB (89%, p = 0.03 and 81%, p = 0.001, respectively). Limitations include limited generalisability, as a transperineal biopsy route was used. CONCLUSIONS: TS detected significantly more cases of sPC than TB and extended SB. Given that both 99% of sPC lesions and men harbouring sPC were identified by TS, the results suggest that this approach allows to omit SB cores without compromising sPC detection. PATIENT SUMMARY: Target saturation of magnetic resonance imaging-suspicious prostate lesions provides excellent cancer detection and finds fewer low-risk tumours than the current gold standard combination of targeted and systematic biopsies.

Prostate specific membrane antigen-radio guided surgery using Cerenkov luminescence imaging-utilization of a short-pass filter to reduce technical pitfalls.

BACKGROUND: Intraoperative Cerenkov luminescence imaging (CLI) is a novel technique to assess surgical margins in patients undergoing nerve sparing radical prostatectomy (RP). Here, we analyze the efficacy of a 550-nm optical short-pass filter (OF) to improve its performance. METHODS: In this prospective single-center feasibility study ten patients with prostate cancer (PC) were included between December 2019 and April 2020, including three patients without tracer injection as a control group. After preoperative injection of 68-Ga-prostate-specific membrane antigen (PSMA)-11 followed by RP, CLI of the excised prostate and the incised index lesion was performed to visualize the primary tumor lesion. We compared the findings on intraoperative CLI to postoperative histopathology. Furthermore, CLI-intensities determined as tumor to background ratio (TBR) and contrast to noise ratio (CNR) were measured. RESULTS: Histopathology proved positive surgical margins (PSM) in 3 patients with corresponding findings in CLI. After magnetic resonance imaging (MRI)-informed incision above the index lesion 2 out of 3 prostates demonstrated elevated CLI signals with histopathological confirmation of PC cells. The use of the OF enabled a significant reduction of the area of the regions of interest from a median of 1.80 to 0.15 cm2 (reduction by 85%, P=0.005) leading to increased specificity. Signals due to PSMs were not suppressed by the 550-nm OF. The median TBR was reduced from 3.33 to 2.10. In all three patients of the control group elevated CLI intensities were detected at locations with diathermal energy deposition during surgery. After application of the 550-nm OF these were almost totally suppressed with a TBR of 1.10. Measurements of Cerenkov luminescence intensity with the 550-nm OF showed a significant Pearson's correlation of 0.82 between PSM and the elevated TBR (P=0.003) and a significant Pearson's correlation of 0.66 between PSM and elevated CNR (P=0.04). Measurements without the OF did not correlate significantly. CONCLUSIONS: Intraoperative 68-Ga-PSMA CLI in PC is a tool that warrants further investigation to visualize PSM especially in intermediate and high-risk PC. Intraoperative CLI benefits from usage of a 550-nm OF to reduce false-positive signals.