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Evaluation of the Performance of Glomerular Filtration Rate Measurement Using CT Urography in Patients With a GFR Below 60 mL/Min/1.73 m²

NCT07042698 · Status: NOT_YET_RECRUITING · Phase: NA · Type: INTERVENTIONAL · Enrollment: 70

Last updated 2025-06-29

No results posted yet for this study

Summary

Glomerular filtration rate (GFR), which is the main biomarker used in clinical practice to assess kidney function, is usually estimated from the serum concentration of endogenous markers such as creatinine and/or cystatin C. GFR estimation equations all share the disadvantage of imperfect accuracy due to non-GFR-related determinants of creatinine and cystatin C. When knowing the exact GFR value is necessary for clinical decision-making, measurement by clearance of an exogenous tracer is required. Various tracers are available, some of which are radioactive tracers (99mTc-DTPA and 51Cr-EDTA), while others are iodinated contrast agents (iohexol, iothalamate). GFR measurement procedures are time-consuming and require significant human resources (4 to 5 hours, or even 24 hours for plasma clearances at very low GFR values).Urinary clearance methods may be inaccurate in cases of inadequate voiding. Plasma clearance results may be inaccurate in cases of increased (overestimation) or decreased (underestimation) extracellular volume, low GFR (unless late sampling is performed), or glomerular hyperfiltration. Measuring tracers requires either warm labs for measuring radioactive markers or labs with HPLC (High Performance Liquid Chromatography) chains for iohexol, which are part of an external quality assurance program. The complexity and/or length of GFR measurement procedures, their cost, and laboratory constraints explain why measured GFR is underused in routine clinical practice. There is a critical need to develop GFR measurement methods that are simpler to implement, reliable across the entire GFR spectrum, and widely available. We have demonstrated that it is possible to measure GFR using 4-phase CT urography performed as part of the care of living kidney donor candidates (healthy individuals with normal GFR). The examination takes 10 minutes, requires no biological sampling, and is not subject to potential inaccuracies due to sodium overload or poor bladder emptying.

Conditions

Interventions

OTHER

Glomerular Filtration Rate measurement with iohexol clearance

After performing a 4-phase CT urography (or 3-phase CT scan, with the addition of a 4th phase for research purposes), performed for clinical indications as part of the patient's care, and using iohexol as a contrast agent, patients will undergo a biological measurement of iohexol clearance, based on serum and urine samples taken over 4 periods of 1 hour, between 3 and 7 hours after the CT scan. No iohexol will be reinjected to measure GFR. The CT scan images will be segmented by the investigator to determine the CT-measured GFR.

Sponsors & Collaborators

  • Assistance Publique - Hôpitaux de Paris

    lead OTHER

Study Design

Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Model
SINGLE_GROUP

Eligibility

Min Age
18 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2025-07-15
Primary Completion
2027-07-14
Completion
2027-07-15

Countries

  • France

Study Locations

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Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT07042698 on ClinicalTrials.gov