A fluoroscopic loopogram, in which water- soluble contrast is instilled into an ileal conduit in a retrograde fashion, can be used to evaluate for leak in the early postoperative period and to confirm patent ureteral anastomoses in the setting of hydronephrosis and declining renal function following urinary diversion. Abdominal radiography and fluoroscopic examinations are not useful for detection of tumor recurrence. MRI Abdomen and Pelvis MRI performs well for identifying metastatic disease within the abdomen and pelvis; however, nodal disease is largely based on size criteria. A recent meta-analysis evaluating nodal metastatic disease in the setting of bladder or prostate cancer demonstrated a pooled per-patient sensitivity of 56% and specificity of 94% [61]. There is no relevant literature regarding the use of MRI of the abdomen and pelvis without IV contrast in the evaluation of metastatic UC. Given the improved soft-tissue contrast of MRI compared with CT, MRI of the abdomen and pelvis without IV contrast may be acceptable for the identification of metastatic disease; however, MRI without and with IV contrast is preferred to improve sensitivity. Although MRI can be used for local staging of bladder cancer, the presence of inflammation and fibrosis affects the accuracy of MRI following neoadjuvant chemoradiation, when accuracy drops to only 30% [62]. However, DWI may help distinguish inflammation and fibrosis from tumor; in a small study of 20 patients who underwent low- dose neoadjuvant chemoradiation, MRI had an accuracy rate of 44% in determining pathologic response for T2- weighted imaging alone, 33% for dynamic contrast-enhanced imaging, and 80% for DWI [63]. MRU MRU is a primary imaging test for the comprehensive evaluation of the genitourinary tract and can be used to assess for metastatic disease and metachronous UTUC.
Post Treatment Surveillance of Bladder Cancer. A fluoroscopic loopogram, in which water- soluble contrast is instilled into an ileal conduit in a retrograde fashion, can be used to evaluate for leak in the early postoperative period and to confirm patent ureteral anastomoses in the setting of hydronephrosis and declining renal function following urinary diversion. Abdominal radiography and fluoroscopic examinations are not useful for detection of tumor recurrence. MRI Abdomen and Pelvis MRI performs well for identifying metastatic disease within the abdomen and pelvis; however, nodal disease is largely based on size criteria. A recent meta-analysis evaluating nodal metastatic disease in the setting of bladder or prostate cancer demonstrated a pooled per-patient sensitivity of 56% and specificity of 94% [61]. There is no relevant literature regarding the use of MRI of the abdomen and pelvis without IV contrast in the evaluation of metastatic UC. Given the improved soft-tissue contrast of MRI compared with CT, MRI of the abdomen and pelvis without IV contrast may be acceptable for the identification of metastatic disease; however, MRI without and with IV contrast is preferred to improve sensitivity. Although MRI can be used for local staging of bladder cancer, the presence of inflammation and fibrosis affects the accuracy of MRI following neoadjuvant chemoradiation, when accuracy drops to only 30% [62]. However, DWI may help distinguish inflammation and fibrosis from tumor; in a small study of 20 patients who underwent low- dose neoadjuvant chemoradiation, MRI had an accuracy rate of 44% in determining pathologic response for T2- weighted imaging alone, 33% for dynamic contrast-enhanced imaging, and 80% for DWI [63]. MRU MRU is a primary imaging test for the comprehensive evaluation of the genitourinary tract and can be used to assess for metastatic disease and metachronous UTUC.