Informations générales (source: ClinicalTrials.gov)
External Validation of a Quantitative Computer Aided Diagnostic (QCAD) System for Prostate mpMRI (DIJON-CAD)
Observational
Hospices Civils de Lyon (Voir sur ClinicalTrials)
juin 2018
octobre 2018
29 juin 2024
Multiparametric magnetic resonance imaging (mpMRI) of the prostate combines T2-weighted
imaging, diffusion-weighted imaging and dynamic contrast-enhanced imaging. Correlation
with radical prostatectomy specimens has demonstrated that mpMRI has excellent
sensitivity in detecting prostate cancers (PCa) with a Gleason score ≥7 and cancers with
a Gleason 6 and a volume ≥0.5 cc. Nevertheless, its specificity is poor and there is
large overlapping between the appearances of benign and malignant prostate lesions. As a
result, the use of a 5-point subjective score has been widely encouraged to describe the
level of suspicion of prostate lesions. This so-called 'Likert score' is a highly
significant predictor of the malignant nature of prostate focal lesions. However, because
there are no descriptions of specific criteria to be used in the scoring process, the
Likert score relies heavily on the reader's experience.
In an attempt to standardize mpMRI interpretation, the European Society of Urogenital
Radiology and the American College of Radiology recently endorsed the so-called Prostate
Imaging-Reporting and Data System (PIRADS) score. The second version of this scoring
system (PI-RADS v2 score) gave good results in characterizing prostate focal lesions.
However, Inter-reader agreement remains moderate at best, even after training, and there
is still a high-rate of false positives. These results have led some authors to suggest
that there might be structural limits to the ability of any score based on MR imaging to
allow detection of prostate cancer with high specificity.
Using quantitative magnetic resonance (MR) image features to characterize prostate
lesions seen on mpMRI could improve interpretation standardization, and recently, several
computer-aided diagnosis (CAD) systems combining various image features have shown
promising results in characterizing prostate tissues. However, most CAD systems have been
trained and evaluated on images from the same MR scanner. Unfortunately, quantification
in MR imaging is limited by substantial inter-manufacturer variability in the calculation
of quantitative image parameters. The quantitative thresholds defined for one
manufacturer may therefore not be valid for another manufacturer. Of the many reported
CAD systems, only few have shown robust results at cross-validation in datasets from
different manufacturers.
We developed in Lyon a mpMRI CAD system for discriminating Gleason ≥7 cancers in the
peripheral zone (PZ). That CAD system was trained using mpMRI from patients treated by
radical prostatectomy. It combines the 10th percentile of the apparent diffusion
coefficient (ADC_10th) and the time to the peak of enhancement (TTP) at dynamic
contrast-enhanced (DCE) imaging. It provided good results when cross-validated in two
datasets from two different manufacturers (General Electric and Philips). We then tested
the CAD on a cohort of 130 patients who underwent mpMRI (General Electric or Philips MR
unit) before prostate biopsy. Each MR lesion targeted at biopsy had prospectively
received a Likert score of likelihood of malignancy at the time of the biopsy.
Retrospective analysis of these MR lesions with the CAD showed that the stand-alone CAD
outperformed the Likert score in predicting the presence of Gleason ≥7 cancer at biopsy
(Area under the receiver operating characteristic curve (AUC): 0.94 (95% confidence
interval (95CI): 0.90-0.98 versus 0.81 (95CI: 0.75-0.88), p<0.0002)). These good results
encourage us to perform an external validation of the CAD testing its performance on
mpMRI from another manufacturer (Siemens) and another institution.
The principal objective of the DIJON-CAD study is to evaluate the performances of the
QCAD developed in Lyon (QCAD/Lyon) in a cohort of consecutive patients treated by
prostatectomy and who underwent preoperative mpMRI on a Siemens 3 Tesla MR imager at the
Dijon University Hospital center or at the Dijon Cancer Center (both institutions share
the same MR unit). This study is the first step of the external validation of the
QCAD/Lyon system. It is only aimed at verifying that the diagnostic performance of the
system is not very poor on external mpMRI (which is a substantial risk). If the results
are good, a proper multicentric prospective validation study will be planned.
Etablissements
Les établissements hors Île-de-France dont les données sont issues de ClinicalTrials.gov Origine et niveau de fiabilité des données | |||||
---|---|---|---|---|---|
Department of biostatistics, Université Joseph Fourrier - Grenoble - France | Contact (sur clinicalTrials) | ||||
Department of pathology, CHU de Dijon - Dijon - France | Contact (sur clinicalTrials) | ||||
Department of radiology and nuclear medicine, Centre anti-cancéreux Georges-François Leclerc, Dijon - Dijon - France | Contact (sur clinicalTrials) | ||||
Department of vascular and urinary imaging, hôpital Edouard Herriot, Hospices Civils de Lyon - 69003 - Lyon - France | Olivier ROUVIERE, Pr | Contact (sur clinicalTrials) | |||
LabTau, INSERM unit 1032, Lyon - Lyon - France | Contact (sur clinicalTrials) | ||||
Les établissements sans correspondance certaine dans le répertoire FINESS dont les données sont issues de ClinicalTrials.gov Origine et niveau de fiabilité des données | |||||
Department of radiology, CHU de Dijon - Dijon - France | Contact (sur clinicalTrials) | ||||
Department of urology, CHU de Dijon - Dijon - France | Contact (sur clinicalTrials) |
Critères
Homme
Inclusion Criteria:
- male over 18 year-old
- treated by prostatectomy for prostate cancer
- who undergone a preoperative mpMRI at 3 Tesla at the Dijon University Hospital or at
the Dijon Cancer center
- non opposition of the patient
- male over 18 year-old
- treated by prostatectomy for prostate cancer
- who undergone a preoperative mpMRI at 3 Tesla at the Dijon University Hospital or at
the Dijon Cancer center
- non opposition of the patient
- Patients who received prior treatment for prostate cancer (hormonotherapy, external
beam radiation therapy, brachytherapy)