OBJECTIVE: The purpose of our study was to assess the feasibility of using C-arm CT to detect incomplete accumulation of iodized oil in hepatocellular carcinoma immediately after transarterial chemoembolization (TACE). MATERIALS AND METHODS: This retrospective study included 80 hepatocellular carcinoma lesions in 55 patients (41 men and 14 women; mean age, 69.2 years; mean tumor size, 18.1 mm [range, 5-55 mm]) who underwent TACE with a flat-detector C-arm angiographic system. C-arm CT images were acquired at the end of each session, and unenhanced MDCT images were obtained 7 days later. Two independent observers scored both sets of images, using a predefined detection scale for incomplete iodized oil accumulation. The accuracy for predicting residual lesions was compared using the area under the receiver-operating characteristic curve (A(z)). Contrast-enhanced CT findings obtained 1 month after TACE served as reference standards. RESULTS: Viable lesions were observed in 18 of the 80 study lesions by contrast-enhanced CT. The accuracy of the C-arm CT (A(z) = 0.816) was not significantly different (p = 0.449) from that of the MDCT (A(z) = 0.841). Sensitivity, specificity, and positive and negative predictive values for C-arm CT (80.5%, 74.2%, 47.5%, and 92.9%, respectively) and MDCT (86.1%, 75.0%, 50.0%, and 94.9%, respectively) did not differ significantly. CONCLUSION: C-arm CT is nearly equivalent to MDCT for detecting incomplete iodized oil accumulation after TACE, suggesting that the immediate assessment of iodized oil accumulation with C-arm CT without the need to perform follow-up unenhanced MDCT is likely feasible.
OBJECTIVE: The purpose of our study was to assess the feasibility of using C-arm CT to detect incomplete accumulation of iodized oil in hepatocellular carcinoma immediately after transarterial chemoembolization (TACE). MATERIALS AND METHODS: This retrospective study included 80 hepatocellular carcinoma lesions in 55 patients (41 men and 14 women; mean age, 69.2 years; mean tumor size, 18.1 mm [range, 5-55 mm]) who underwent TACE with a flat-detector C-arm angiographic system. C-arm CT images were acquired at the end of each session, and unenhanced MDCT images were obtained 7 days later. Two independent observers scored both sets of images, using a predefined detection scale for incomplete iodized oil accumulation. The accuracy for predicting residual lesions was compared using the area under the receiver-operating characteristic curve (A(z)). Contrast-enhanced CT findings obtained 1 month after TACE served as reference standards. RESULTS: Viable lesions were observed in 18 of the 80 study lesions by contrast-enhanced CT. The accuracy of the C-arm CT (A(z) = 0.816) was not significantly different (p = 0.449) from that of the MDCT (A(z) = 0.841). Sensitivity, specificity, and positive and negative predictive values for C-arm CT (80.5%, 74.2%, 47.5%, and 92.9%, respectively) and MDCT (86.1%, 75.0%, 50.0%, and 94.9%, respectively) did not differ significantly. CONCLUSION: C-arm CT is nearly equivalent to MDCT for detecting incomplete iodized oil accumulation after TACE, suggesting that the immediate assessment of iodized oil accumulation with C-arm CT without the need to perform follow-up unenhanced MDCT is likely feasible.