Quantitative Assessment of Lipiodol Deposition after Chemoembolization: Comparison between Cone-Beam CT and Multidetector CT

Purpose: To evaluate the ability cif cone-beam computed tomography (CBCT) performed directly after transarterial chemoembolization to assess,ethiodized oil (Lipiodol) deposition in hepatocellular carcinoma (HCC) and compare it with unenhanced multidetector Computed tomography (CT). Materials and Methods: Conventional transarterial chemoembolization was used to treat 15 patients with HCC, and CBCT was performed to-assess Lipiodol deposition directly after transarterial chemoembolization. Unenhanced multidetector CT was-performed 24 hours after transarterial chemoembolization. Four patients were excluded because the margin of tumor or area of Lipiodol deposition-was unclear. The image enhancement density of the entire tumor and liver parenchyma was measured by ImageJ software, and tumor-to-liver contrast (TLC) was calculated. In addition, volumetric measurement of tumor and Lipiodol was performed by semiautomatic three-dimensional volume segmentation and compared using linear regression to evaluate consistency between the two imaging modalities. Results: The mean value of:TLC on CBCT was not significantly different from TLC on multidetector CT (337.7 HU +/- 233.5 vs 283.0 HU +/- 152.1, P =.103). The average volume of the whole tumor and of only the regions with Lipiodol deposition and the calculated. average percentage-of Lipiodol retention on CBCT Were not Significantly different compared with multidetector CT (tumor volume, 9.6 cm(3) +/- 11.8 vs 10.8 cm(3) +/- 14.2, P = .142; Lipiodol volume, 6.3 cm(3) +/- 7.7 vs 7.0 cm(3) +/- 8.1, P = .214; percentage of Lipiodol retention, 68.9% +/- 24.0% vs 72.2% +/- 23.1%, P = .578). Additionally, there was a high correlation in the volume of tumor and Lipiodol between. CBCT and multidetector CT (R-2 = 0.919 and 0.903). Conclusions: The quantitative image enhancement and volume analyses demonstrate that CBCT is similar to multidetector CT in assessing Lipiodol deposition in HCC after transarterial chemoembolization.