Role of diffusion‐weighted magnetic resonance imaging as an imaging biomarker of urothelial carcinoma

Abstract

Abbreviations & Acronyms ADC = apparent diffusion coefficient BC = bladder cancer CCRCC = clear cell renal cell carcinoma CRT = chemoradiotherapy DCE-MRI = dynamic contrast-enhanced magnetic resonance imaging DW-MRI = diffusion-weighted magnetic resonance imaging G = grade Ki-67 LI = Ki-67 labeling index MIBC = muscle-invasive bladder cancer MRI = magnetic resonance imaging NMIBC = non-muscle invasive bladder cancer NR = not reported P = pelvis Pts = patients ROI = regions of interest T2W-MRI = T2-weighted magnetic resonance imaging TURB = transurethral resection of the bladder U = ureter U/C = urinary cytology UTUC = upper tract urothelial carcinoma Abstract: Diffusion-weighted magnetic resonance imaging is a type of functional imaging that is increasingly being applied in the management of upper tract urothelial carcinoma and bladder cancer. The image contrast is derived from differences in the Brownian motion of water molecules in tissues. The homogenous high signal intensity of upper tract urothelial carcinoma and bladder cancer on diffusion-weighted magnetic resonance imaging provides helpful diagnostic information for the presence of cancerous lesions in a non-invasive manner. Recently, growing evidence has emerged showing that diffusion-weighted magnetic resonance imaging can serve as an imaging biomarker for characterizing cancer pathophysiology, because the signal reflects biophysical information about the tissues. Quantitative analysis by evaluating the apparent diffusion coefficient values potentially reflects the histological grade and the biological aggressiveness of urothelial carcinoma. The apparent diffusion coefficient value could be a biomarker predicting the clinical course of upper tract urothelial carcinoma and bladder cancer. In addition, in chemoradiotherapy-based bladdersparing approaches against muscle-invasive bladder cancer, the role of diffusion-weighted magnetic resonance imaging for predicting the chemoradiosensitivity and for monitoring therapeutic response has been shown. Diffusion-weighted magnetic resonance imaging is expected to improve the diagnostic accuracy, and this qualitative information might allow individualized treatment strategies for patients with urothelial carcinoma.

Clinical staging of upper urinary tract urothelial carcinoma for T staging: Review and pictorial essay

“…Yoshida et al . found that the additional use of DWI to T1WI and T2WI increases sensitivity with excellent interobserver agreement, and that DWI could be a useful adjunct to preoperative assessment of histological grade . Consistent with previous results, Yoshida et al .…”

“…Recent studies reported that ADC inversely correlates with immunohistochemical and histological grading of upper UTUC and also that upper UTUC with lower ADC is more likely to have a metastatic potential . Therefore, ADC can be a biomarker that can predict the clinical course and prognosis of patients with upper UTUC . However, other studies reported that correlation between histological grade and ADC was controversial .…”

Utility of intravoxel incoherent motion MRI derived parameters for prediction of aggressiveness in urothelial bladder carcinoma

“…Diffusion‐weighted MR imaging (DWI) with apparent diffusion coefficient (ADC) has shown value for characterizing the aggressiveness of bladder cancer . Nevertheless, the conventional DWI‐derived ADC calculated with monoexponential model contains water molecular diffusion and microcirculation perfusion information.…”

Potential Utility of Diffusion-Weighted Magnetic Resonance Imaging in Diagnosis of Residual Bladder Cancer before Second Transurethral Resection

“…In bladder cancer management, DW-MRI has been reported to be useful in detection, characterization of histopathological features, prediction of therapeutic sensitivity, and therapeutic assessment [8,10,13,20,[22][23][24][25][26] . Recently, a high accuracy of DW-MRI has been reported during year- ly follow-up after TURB.…”

“…Bladder cancers generally show a hyperintense signal because of their higher cellularity and tissue disorganization [8,9] . Since the first report showing the usefulness of DW-MRI in the detection of bladder cancer in 2007, DW-MRI has been increasingly applied in the management of bladder cancer [10][11][12][13][14] .…”