Virtual Histology of the Bladder Wall for Bladder Cancer Staging

Overview

This is a phase Ib study of the safety and performance of a novel intravesical contrast-enhanced Magnetic Resonance Imaging protocol for determination of bladder cancer stage prior to transurethral resection of bladder tumor (21 subjects) or prior to radical cystectomy for muscle invasive disease (21 subjects). Subjects will undergo a single MRI study: a pre-contrast, single breath hold image followed by sterile placement of a temporary urethral catheter for instillation of a 50mL solution containing Gadobutrol (4 mM) plus ferumoxytol (5 mM) and then a second, post-contrast image. Images will be reviewed by two dedicated abdominal radiologists, who are blinded to the pathologic staging, for determination of tumor presence and depth of bladder wall penetration.

Twenty one patients with at least one cystoscopically confirmed papillary bladder tumor, who have been scheduled for Transurethral Resection of Bladder Tumor (TURBT) for surgical extirpation and staging, and twenty-one patients with histologically confirmed, muscle invasive transitional cell carcinoma of the bladder who have been scheduled for definitive radical cystectomy with curative intent will be recruited for a single study Magnetic Resonance Imaging to be performed between 1 and 6 days prior to their scheduled procedure. Magnetic Resonance Imaging of all the enrolled patients will be performed on a 60-cm, wide-bore, 3T scanner (Siemens AG, Erlangen, Germany) with a 32-channel pelvic phased-array coil placed over the bladder using radial k-space sampling technique for volumetric free breathing acquisition with NCM enhanced StarVIBE57. Un-enhanced fast spoiled gradient-echo images with fat suppression will be obtained prior aseptic instillation of 50cc of a novel contrast mixture (NCM) of Gadobutrol (4 mM) plus Ferumoxytol (5 mM) in sterile water through a temporary urethral catheter. The catheter will then be removed and the patient repositioned in the scanner to obtain post-contrast images. All the image datasets will be linearly registered to the subject to ensure that regions of interest represent the same anatomical location at all time points. Post-contrast T1, pre-contrast T1 and deltaT1 will be measured from the acquired images. Two radiologists blinded to the pathologic findings will evaluate the Magnetic Resonance images to assign a radiologic tumor stage that will be compared with the subsequent pathologic stage determined at time of surgery. Following the MRI study, subjects will proceed with their surgical procedure as scheduled per standard of care.