Tumor Staging T of Bladder Tumours: Correlation of MRI and Anatomopathologic Analysis

This is a single center study comparing MRI report to anatomopathological report in participants who were diagnosed with an urinary bladder tumour, histologically confirmed in routine care.

Bladder tumours are frequent pathologies with 13,000 new cases per year in France. They can present various types of damage, from the most benign to the most serious stages, depending on the number, the extent of the lesions and their degree of infiltration (superficial or deeper). We also know that the shorter the treatment time, the better the final prognosis. An infiltrating lesion taken as soon as it is discovered considerably reduces the likelihood of progression. It is therefore necessary to improve patient care.

Currently, when a bladder lesion is visualized by the urologist during the cystoscopy (examination during which the urologist notes the presence or absence of bladder lesion(s)), the only way to know its stage (and its degree of infiltration if applicable) which will determine the follow-up care, consists in carrying out an intervention called Trans Urethral Resection of the Bladder (TURB), in order to remove the lesions which will be analyzed in the anatomopathological laboratory. This analysis is the best interpretation of the tumour stage, carried out in accordance with the international standards, and the only way to have a diagnosis of tumour lesions. Indeed, to date, no imaging technique (ultrasound, scanner, etc.) makes it possible to obtain it.

The CT scan of the urinary tract is currently only used to identify lesions of the upper urinary tract or lymph nodes.

However, in recent years, these techniques have evolved considerably, and studies have shown that MRI seems to have the ability to determine the tumour stage of bladder lesions.

Investigators propose to demonstrate the value of MRI in determining tumour infiltration compared to the anatomopathological analysis of samples taken during TURB. This would provide better patient care in human, pathological, economic and technical terms, by developing a more precise mapping of lesions in the bladder, reducing waiting times for results and therefore obtaining earlier diagnosis, a reduction in the number of consultations, hospitalizations, surgeries more or less morbid, examinations...

Finally, this would potentially :

• Reduce the number of cystoscopies (examination normally painless, but unpleasant and frequent) carried out before TURB but also throughout the monitoring following the TURB,
• Detect very early infiltrating lesions in order to limit their potential extension before the cystectomy.

Inclusion criteria

• Patient, male or female, aged >18ans
• Benefiting from Social Security
• Urinary bladder tumour confirmed on cystoscopy and requiring a TURB
• Understanding and reading French well
• Ability to give informed consent

Exclusion criteria

• Participation refusal
• MRI contraindication : pacemaker, heart valve, clips, stents, coils, non-MRI compatible defibrillators, neural or peripheral stimulator, cochlear implant, intraocular foreign body, claustrophobia
• Patient under guardianship, deprived of liberty, impaired understanding
• Pregnant/breastfeeding woman
• Allergy to gadolinium (contrast product necessary for carrying out the MRI), hypersensitivity to gadoteric acid or gadolinated contrast products, to meglumine
• Suspicion of an infectious disease such as schistosomiasis (differential diagnosis)
• Patient presenting with macroscopic clotting hematuria on the day of the MRI