Subtraction CT with Low-Flow-Rate Arterial Contrast Injection to Estimate Drug Distribution During Balloon-Occluded Arterial Chemotherapy Infusion for Bladder Cancer

Purpose: To simulate drug distribution during balloon-occluded arterial chemotherapy infusion (BOAI) for urinary bladder cancer using subtraction computed tomography (CT) with low-flow-rate arterial contrast injection (S-CTLA).Methods: Ten patients with bladder cancer underwent S-CTLA, and the distribution of contrast agent during BOAI into both internal iliac arteries simultaneously was evaluated in nine pairs of internal iliac arteries and one single artery. For S-CTLA, spiral CT data were acquired before and after 0.2 ml/sec intraarterial injection of contrast material. The enhancement of the urinary bladder wall, the gluteal muscles, and the pelvic bones was categorized using a 4-grade scale. The grades were compared in each of the three pelvic components and differences were tested for significance using the Wilcoxon test for paired groups.Results: S-CTLA revealed the distribution of the contrast agent clearly. Gluteal muscles grades were significantly higher than those of the other two assessed components.Conclusion: BOAI does not improve the concentration of contrast agent to the bladder wall over neighboring structures, suggesting that the balloon occlusion technique does not achieve its desired goal for chemotherapy targeting