Diffusion-weighted MRI in bladder carcinoma: the differentiation between tumor recurrence and benign changes after...

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Distinguishing recurrent bladder cancer from post-surgical changes like inflammation and fibrosis is crucial for effective patient management.
• Conventional imaging techniques may have limitations in accurately differentiating these conditions.

Purpose of the Study:

• To evaluate the diagnostic performance of diffusion-weighted MRI (DWI) compared to dynamic contrast-enhanced MRI (DCE MRI) in identifying recurrent bladder tumors after surgical resection.
• To assess the utility of DWI in differentiating tumor recurrence from chronic inflammation and fibrosis post-cystectomy or transurethral resection.

Main Methods:

• A study involving eleven patients with suspected bladder cancer recurrence who underwent both DWI and DCE MRI.
• Histopathological confirmation of 27 lesions was obtained via transurethral or cystoscopic resection within two weeks of MRI examinations.

Main Results:

• DWI demonstrated higher accuracy (92.6%), sensitivity (100%), specificity (81.8%), and positive predictive value (88.9%) compared to DCE MRI.
• Normalized apparent diffusion coefficients were significantly lower in recurrent tumors (0.697 ± 0.219) than in postoperative inflammation/fibrosis (1.019 ± 0.143).
• DWI diagnostic accuracy showed no significant difference from histopathology, unlike DCE MRI.

Conclusions:

• Diffusion-weighted MRI is superior to dynamic contrast-enhanced MRI for differentiating recurrent bladder tumors from postoperative inflammation or fibrosis.
• DWI should be considered for inclusion in follow-up MRI protocols for patients who have undergone bladder cancer surgery.