Real-time Fluorescence Microscopy for Intraoperative Assessment of Prostate Biopsy Cores (FLASH) (FLASH)

September 23, 2026 updated by: Shanghai East Hospital

Fluorescence Microscope for Localized Assessment and Sparing of Histology in Prostate Cancer (FLASH): An International, Multicentre, Prospective Diagnostic Accuracy and Clinical Utility Study With Blinded Index-Test and Reference-Standard Readers

Current prostate cancer diagnosis relies on MRI-targeted biopsy combined with a 12-core systematic biopsy. The systematic component is a major driver of overdiagnosis of insignificant cancer and biopsy-related morbidity, and conventional pathology takes 1-2 weeks, causing significant patient anxiety. The EndoScell system is a handheld, real-time fluorescence microscope that can display the microscopic structure of a fresh biopsy core within minutes, without damaging the tissue.

In this study, every biopsy core from men undergoing standard combined (targeted plus systematic) prostate biopsy will be scanned with this device immediately after removal, and the result will be compared with the final conventional pathology report of the very same core. The device result will not be used to guide any patient care. The study will measure how accurate the device is and simulate how many systematic biopsies could safely be avoided in the future if a positive device reading were used to stop further sampling.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

FLASH is an investigator-initiated, international, multicentre, prospective diagnostic-accuracy and clinical-utility study with a within-patient paired design, conducted and reported in accordance with STARD 2015. Biopsy-naïve men with suspected prostate cancer (serum PSA >4 ng/mL and/or abnormal digital rectal examination) and at least one MRI-visible lesion (PI-RADS v2.1 score 3-5) will undergo standard-of-care combined targeted and systematic prostate biopsy.

Immediately after extraction, every core will undergo ex vivo dual staining (fluorescein sodium for 30 seconds followed by methylene blue for 30 seconds) and contact-mode scanning with the EndoScell real-time fluorescence microscope (model MES-1000P), completed within 5 minutes per core by certified technicians. Each core is assigned to a three-tier category (0 = negative/suspected low-grade; 1 = suspected clinically significant prostate cancer; 2 = equivocal). The interval from core extraction to formalin fixation will not exceed 15 minutes. All cores then undergo routine formalin-fixed paraffin-embedded (FFPE) histopathology with haematoxylin and eosin staining, with immunohistochemistry as clinically indicated, reported by senior uropathologists.

Bidirectional blinding is enforced throughout: technicians are blinded to all clinical data, MRI findings, and core origin; device results are withheld from the treating team and never enter the medical record; uropathologists are blinded to all device data; the statistician works with coded variables until database lock. Central pathology review is performed for discordant and equivocal cases.

The primary outcome is patient-level diagnostic accuracy (sensitivity, specificity, positive and negative predictive values with exact 95% confidence intervals) of the device for clinically significant prostate cancer (ISUP grade group >=2) against FFPE histopathology in the intention-to-diagnose population. Secondary outcomes include core-level concordance with cluster adjustment, inter-reader reproducibility, tissue-integrity assessment, operational metrics, and a prespecified decision-analytic simulation of a "Positive-then-Stop" biopsy-sparing pathway, which is hypothesis-generating and does not alter patient care. The accuracy and utility estimates are intended to inform the design of a future randomised de-implementation trial.

Study Type

Observational

Enrollment (Estimated)

450

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

40 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Sampling Method

Probability Sample

Study Population

patients who suspected to have prostate cancer

Description

Inclusion Criteria:

  1. Age >= 40 years;
  2. Serum total PSA > 4.0 ng/mL and/or abnormal digital rectal examination;
  3. Biopsy-naïve;
  4. Pre-biopsy 3.0-T multiparametric MRI demonstrating at least one suspicious lesion (PI-RADS v2.1 score 3-5);
  5. Fit for transperineal or transrectal prostate biopsy under local, regional, or general anaesthesia;
  6. Written informed consent.

Exclusion Criteria:

  1. Prior treatment for prostate cancer (surgery, radiotherapy, focal therapy, or androgen-deprivation therapy), or use of 5-alpha-reductase inhibitors within the preceding 6 months;
  2. Acute prostatitis or active urinary tract infection;
  3. Contraindications to MRI (e.g., incompatible implants, severe claustrophobia);
  4. Severe coagulation disorders or uncorrectable bleeding tendency;
  5. History of major anorectal surgery precluding safe insertion of the endorectal ultrasound probe (where transrectal guidance is used);
  6. Any other condition that, in the investigator's judgement, makes the participant unsuitable for the trial.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: COHORT
  • Time Perspectives: PROSPECTIVE

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Biopsy-naïve men with suspected prostate cancer

Men undergoing standard-of-care combined targeted plus systematic prostate biopsy; every core undergoes ex vivo EndoScell fluorescence microscopy (index test) followed by FFPE histopathology (reference standard). Device results are not used for patient care.
Diagnostic test: Ex vivo real-time fluorescence microscopy of prostate biopsy cores (EndoScell system, model MES-1000P)

Fresh biopsy cores are stained with fluorescein sodium (30 s) and methylene blue (30 s), scanned in contact mode within 5 minutes per core, and categorised on a three-tier scale; the tissue then proceeds to routine FFPE histopathology unchanged. The test is performed on excised tissue only and does not influence clinical management.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Patient-level sensitivity of the EndoScell system for clinically significant prostate cancer
Time Frame: Index test on Day 0; reference standard completed Day 7-14

Proportion of reference-positive participants (any core with ISUP grade group >=2 on FFPE histopathology) with at least one core read as Category 1 (suspected clinically significant prostate cancer) on the index test; reported with exact (Clopper-Pearson) 95% confidence interval in the intention-to-diagnose population.
Index test on Day 0; reference standard completed Day 7-14
Patient-level negative predictive value (NPV) of the EndoScell system
Time Frame: Index test on Day 0; reference standard completed Day 7-14

Proportion of participants with no Category 1 core who are reference-negative; exact 95% CI.
Index test on Day 0; reference standard completed Day 7-14
Patient-level positive predictive value (PPV) of the EndoScell system
Time Frame: Index test on Day 0; reference standard completed Day 7-14

Proportion of participants with at least one Category 1 core who are reference-positive (ISUP grade group >=2 on FFPE); exact 95% CI.
Index test on Day 0; reference standard completed Day 7-14
Patient-level specificity of the EndoScell system for clinically significant prostate cancer
Time Frame: Index test on Day 0; reference standard completed Day 7-14

Proportion of reference-negative participants with no core read as Category 1; equivocal (Category 2) readings are grouped with test-negative in the primary analysis, with worst-case/best-case/exclusion sensitivity analyses prespecified; exact 95% CI.
Index test on Day 0; reference standard completed Day 7-14

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Core-level diagnostic concordance
Time Frame: Index test on Day 0; reference standard completed Day 7-14

Per-core sensitivity, specificity, PPV and NPV of the index test against FFPE histopathology, overall and stratified by core origin (targeted vs systematic), with cluster-robust 95% CIs from a generalised estimating equation (logit link, exchangeable correlation) accounting for within-patient clustering.
Index test on Day 0; reference standard completed Day 7-14
Biopsy-sparing rate of the simulated "Positive-then-Stop" pathway
Time Frame: Simulation performed after database lock (estimated December 2028)

Proportion of participants in whom systematic biopsy would have been omitted (any targeted core read as Category 1), and the corresponding proportion of systematic cores avoided; prespecified deterministic simulation, exact 95% CIs. Hypothesis-generating; does not alter patient care.
Simulation performed after database lock (estimated December 2028)
Overdiagnosis reduction in the simulated pathway
Time Frame: Simulation performed after database lock (estimated December 2028)

Number and proportion of ISUP grade group 1 diagnoses that would have been averted by omitting systematic biopsy after a positive intraoperative reading; exact 95% CI.
Simulation performed after database lock (estimated December 2028)
Clinically significant prostate cancer miss rate in the simulated pathway
Time Frame: Simulation performed after database lock (estimated December 2028)

Number and proportion of reference-positive participants who would have been missed under the simulated pathway (targeted cores negative on both index test and FFPE, with csPCa found only in systematic cores); exact 95% CI.
Simulation performed after database lock (estimated December 2028)
Net benefit of the simulated pathway (decision-curve analysis)
Time Frame: Simulation performed after database lock (estimated December 2028)

Decision-curve analysis with patient-level bootstrap (1000 resamples) comparing three strategies (combined biopsy for all; targeted biopsy alone; Positive-then-Stop) across threshold probabilities.
Simulation performed after database lock (estimated December 2028)
Inter-reader agreement of index-test readings
Time Frame: Video re-reading after completion of enrolment (estimated 2028)

Cohen's kappa (three-tier scale and dichotomised Category 1 vs 0/2) and percent agreement between two blinded technicians re-interpreting a random 20% subset of archived scan videos (~900-1200 cores).
Video re-reading after completion of enrolment (estimated 2028)
Tissue-integrity (tissue-compromise) rate
Time Frame: Day 7-14 (pathology reporting)

Proportion of cores flagged by uropathologists as degraded, unreadable, or inadequate for definitive H&E/IHC evaluation attributable to the staining/scanning procedure; one-sided upper 95% confidence bound compared against the 1% acceptability benchmark.
Day 7-14 (pathology reporting)
Operational performance of the index test
Time Frame: Day 0

Per-core scanning time, extraction-to-fixation interval, equivocal (Category 2) rate, and device/scan failure rate, summarised descriptively by centre and calendar quarter.
Day 0

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Shanghai East Hospital

Investigators

  • Study Chair: haifeng wang, Changhai Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

December 1, 2026

Primary Completion (Estimated)

December 1, 2028

Study Completion (Estimated)

January 1, 2029

Study Registration Dates

First Submitted

September 23, 2026

First Submitted That Met QC Criteria

September 23, 2026

First Posted (Actual)

September 29, 2026

Study Record Updates

Last Update Posted (Actual)

September 29, 2026

Last Update Submitted That Met QC Criteria

September 23, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2026304

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified participant-level data and the signed statistical analysis plan will be made available on reasonable request to the corresponding author, subject to a methodologically sound proposal and a signed data-access agreement.

IPD Sharing Time Frame

Beginning 12 months after publication of the primary results, for a period of 5 years.

IPD Sharing Access Criteria

Proposals will be reviewed by the Trial Steering Committee; access requires approval and a data-access agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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