Journal article
Computed tomography-derived extracellular volume fraction is associated with high-grade recurrence in non-muscle-invasive bladder cancer treated with intravesical gemcitabine and docetaxel
BJU international
05/28/2026
DOI: 10.1111/bju.70319
PMID: 42206900
Abstract
To evaluate whether extracellular volume (ECV) fraction derived from contrast-enhanced computed tomography (CT) is associated with recurrence risk in patients with treatment-naïve high-risk non-muscle-invasive bladder cancer (HR-NMIBC) receiving intravesical gemcitabine/docetaxel (Gem/Doce) therapy.
This retrospective cohort study, conducted at a tertiary referral centre, included 103 patients with HR-NMIBC treated with intravesical Gem/Doce between 2012 and 2024. All patients underwent pre-resection contrast-enhanced CT with an equilibrium phase (~3 min post-injection). Tumour ECV fraction (%) was calculated using the formula: ECV = (ΔHUtumour/ΔHUaorta) × (1 - haematocrit) × 100, where Δ Hounsfield units (HU) represents the change in attenuation between non-contrast and equilibrium phases. Regions of interest were manually placed in the tumour and abdominal aorta, and haematocrit values obtained within ±10 days were used. Associations between clinical variables, ECV, and recurrence were evaluated using Cox proportional hazards models, with discrimination assessed by Uno's C-statistic.
The median (interquartile range) follow-up was 17 (10-25) months. High-grade recurrence-free survival (HG-RFS) was 76% at 12 months and 69% at 24 months. CT-derived ECV was the only variable significantly associated with HG-RFS (hazard ratio 1.05, 95% confidence interval 1.03-1.08), demonstrating strong discrimination (C-statistic, 0.81; P < 0.01). A 15% threshold offered the best sensitivity-specificity trade-off (~70% each) for predicting HG-RFS at 12 and 24 months. Patients with ECV ≤15% had markedly better HG-RFS than those with ECV >15% at 24 months (88% vs 41%).
The CT-derived ECV is a practical, first-of-its-kind imaging biomarker associated with recurrence risk and useful for risk stratification in patients with HR-NMIBC treated with intravesical Gem/Doce, a regimen increasingly used in the setting of global Bacillus Calmette-Guérin shortages and intolerance. ECV can be rapidly quantified from routine contrast-enhanced CT using standard picture archiving and communication system (PACS) tools, without additional imaging or proprietary software, making it a feasible metric for integration into risk-adapted management pending large-scale validation with extended follow-up.
Details
- Title: Subtitle
- Computed tomography-derived extracellular volume fraction is associated with high-grade recurrence in non-muscle-invasive bladder cancer treated with intravesical gemcitabine and docetaxel
- Creators
- Mohamad Abou Chakra - University of IowaIssa Alsamarah - University of Iowa Health CareHelen Y Hougen - University of IowaYousef Zakharia - Mayo Clinic in ArizonaJames A Brown - University of IowaAmanda A Myers - University of IowaKathryn A Marchetti - University of IowaGrant M Henning - University of IowaSarah L Mott - University of IowaIgor Duquesne - Hôpitaux Universitaires Henri-MondorBogdan Adrian Buhas - Groupe Hospitalier Diaconesses Croix Saint-SimonMichael A O'Donnell - University of Iowa Health Care
- Resource Type
- Journal article
- Publication Details
- BJU international
- DOI
- 10.1111/bju.70319
- PMID
- 42206900
- NLM abbreviation
- BJU Int
- ISSN
- 1464-410X
- eISSN
- 1464-410X
- Publisher
- Wiley
- Grant note
- John and Carol Walter Family Foundation
This work was supported by the John and Carol Walter Family Foundation.
- Language
- English
- Electronic publication date
- 05/28/2026
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Hematology, Oncology, and Blood & Marrow Transplantation; Urology; Internal Medicine
- Record Identifier
- 9985166870202771
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