Advanced imaging techniques in the therapeutic response of transarterial chemoembolization for hepatocellular carcinoma

Abstract

Hepatocellular carcinoma (HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization (TACE) can significantly improve the survival rate of patients with HCC and is the first treatment choice for patients who are not suitable for surgical resections. The evaluation of the response to TACE treatment affects not only the assessment of the therapy efficacy but also the development of the next step in the treatment plan. The use of imaging to examine changes in tumor volume to assess the response of solid tumors to treatment has been controversial. In recent years, the emergence of new imaging technology has made it possible to observe the response of tumors to treatment prior to any morphological changes. In this article, the advances in studies reporting the use of computed tomography perfusion imaging, diffusion-weighted magnetic resonance imaging (MRI), intravoxel incoherent motion, diffusion kurtosis imaging, magnetic resonance spectroscopy, magnetic resonance perfusion-weighted imaging, blood oxygen level-dependent MRI, positron emission tomography (PET)/computed tomography and PET/MRI to assess the TACE treatment response are reviewed.

Keywords: Blood oxygen level-dependent; Chemoembolization; Computed tomography perfusion imaging; Diffusion kurtosis imaging; Diffusion-weighted imaging; Hepatocellular carcinoma; Intravoxel incoherent motion; Magnetic resonance perfusion-weighted imaging; Magnetic resonance spectroscopy.

Figure 1

Seventy-year-old male patient with hepatocellular carcinoma. Axial perfusion images of the tumor before transarterial chemoembolization were created by maximum slope method. The tumor showed an increased hepatic arterial perfusion and decreased hepatic portal perfusion compared with the normal parenchyma. The values of hepatic arterial perfusion, hepatic portal perfusion, total liver perfusion and hepatic arterial perfusion index were 0.512 mL/min.mL, 0.226 mL/min.mL, 0.738 mL/min.mL and 69.4%, respectively. A: Image of hepatic arterial perfusion; B: Image of hepatic portal perfusion; C: Image of total liver perfusion; D: Image of hepatic arterial perfusion index.

Figure 2

Fifty-three-year-old female patient with hepatocellular carcinoma in the right lobe of the liver. A: Axial T1-weighted image shows a hypointense mass lesion; B: Axial T2-weighted image shows a hyperintense mass lesion; C: Contrast-enhanced MRI during the arterial phase showing lesion enhancement; D: Mapping of the estimated value of the D parameter. The average value in the lesion ROI was D = 1.22 × 10^-3 mm²/s; E: Mapping of the estimated value of the D* parameter. The average value in the lesion ROI was D* = 20.6 × 10^-3 mm²/s; F: Mapping of the perfusion fraction (f) with a value of 19.6%.