April 16, 2020
Lipiodol Evaluated as an Imaging Biomarker of Tumor Response After cTACE
April 16, 2020—Findings from a single-center, single-arm study support the use of Lipiodol (Guerbet LLC) as an imaging biomarker of tumor response after conventional transarterial chemoembolization (cTACE) for both primary and secondary liver cancer.
Milena A. Miszczuk, MD, et al found that Lipiodol deposition in liver tumors can be predicted using quantitative baseline imaging characteristics and correlates with tumor response. The study is available online in Translational Oncology.
As summarized in Translational Oncology, the prospective clinical trial enrolled a total of 39 patients with primary or secondary liver malignancy (hepatocellular carcinoma [HCC], n = 22; non-HCC, n = 17).
Patients were treated with cTACE according to a standardized protocol. They underwent multimodality imaging at baseline (MRI/CT/positron emission tomography [PET]); at 24 hours post-TACE (CT); and at 30, 90, and 180 days post-TACE (MRI/CT/PET).
Image data analysis included a quantitative assessment of tumor characteristics, Lipiodol deposition, fluorodeoxyglucose uptake, and tumor-response assessment. Statistical analysis included linear regression, Student's t-tests, Wilcoxon rank-sum and signed-rank test, Chi-square test, and Fisher's exact test.
In Translational Oncology, the investigators reported the following findings:
- Image analysis demonstrated that baseline tumor diameter (R2 = 0.4; P = .0001), area R2 = 0.45; P < .0001), volume R2 = 0.3; P < .002), and enhancing volume (cm3; R2 = .23; P < .002) at baseline correlated inversely with Lipiodol tumor coverage and response rates.
- Baseline tumor enhancement in percent of the total tumor was the only parameter to positively correlate with Lipiodol coverage (R2 = .189; P = .0456).
- Patients with high lipiodol coverage of the tumors showed a higher tumor quantitative European Association for the Study of the Liver response rate at 30-day follow-up (P = .004).
- Lipiodol retention in both primary and secondary liver tumors was sustained over time but nontarget hepatic deposits demonstrated near-complete elimination at 30-day follow-up (P < .001).
Julius Chapiro, MD, PhD, Co-Director of the Yale Interventional Oncology Research Laboratory in New Haven, Connecticut, ran the trial with Dr. Miszczuk, as well as Jean-Francois H. Geschwind, MD, and Todd Schlachter, MD.
Explaining the key findings to Endovascular Today on behalf of the research team, Dr. Chapiro stated, “Our quantitative multimodality image analysis confirms the previously suggested unique function of lipiodol as a theranostic imaging biomarker for tumor response in cTACE. Interestingly, we observed tumor-specific deposition and longitudinal retention of Lipiodol predominantly in patients with hepatocellular carcinoma, an effect that was much less prevalent in metastatic lesions. At the same time, we demonstrated that nontumorous liver parenchyma did not retain deposited Lipiodol at all which again underlined the tumor-specific functions of Lipiodol as an injectable imaging biomarker for cancer.”
Additionally, Dr. Chapiro advised, “Those clinical findings correlate well with our previously published experimental data from animal studies, which hinted at lysosomal processing and breakdown of Lipiodol within the mononuclear phagocyte system as the possible route of elimination (Theranostics; 2019;9:3674–3686).”