Application of intravoxel incoherent motion diffusion-weighted imaging in hepatocellular carcinoma

Table 1 Summary of locoregional therapy studies

Ref.	Country	Subject number	Key findings
Juan et al[46], 2019	China	20	After TACE, the ADC and Dslow values of HCC increased significantly, and the value of Dfast decreased significantly; the f value did not change markedly.
Wu et al[47], 2019	China	55	Compared with nonresponders, the mean, median, and 25th percentile of the PF, ADC, and ADCtotal were higher in responders, while the skewness and kurtosis of PF, kurtosis of ADC and ADCtotal were lower
Lin et al[48], 2016	China	118	Before TACE, significant differences in ADC, Dslow and Dfast were observed between the effective and ineffective groups. After TACE, the effective group exhibited lower Dfast and higher ADC and Dslow values than the ineffective group. The tumor regression rate was negatively correlated with Dfast but positively correlated with ADC and Dslow
Park et al[50], 2014	Korea	44	The preoperative D* value was significantly increased in the good lipiodol uptake group compared with the poor uptake group after TACE, while the ADC, D, and f values were not significantly different between these two groups
Jia F et al[51], 2020	China	56	ROC curve analyses revealed that the combined model including APT SIs and D values was better able to predict the tumor response to TACE than the individual parameters
Wu L et al[52], 2017	China	30	The ADCtotal ratio and D ratio measured 24-48 h after TACE were independent predictors of the response to TACE of patients with HCC and showed stronger associations with PFS than mRECIST criteria
Hectors et al[53], 2020	United States	24	The ADC and D values of HCC were significantly increased at six weeks after radioembolization, while the D* values were significantly reduced, with no significant change in f values
Server et al[54], 2019	Turkey	15	The ADC and D values after LRT were significantly higher than those measured before treatment, while the f values were significantly lower than those recorded before LRT. In the responder group, the ADC and D values were significantly increased after LRT, whereas the f values were significantly reduced

TACE: Transarterial chemoembolization; ADC: Apparent diffusion coefficient; HCC: Hepatocellular carcinoma; PF: Perfusion fraction; ROC: Receiver operating characteristic; APT: Amide proton transfer; SIs: Signal intensities; PFS: Progression-free survival; LRT: Locoregional therapy.

Table 2 Summary of systemic therapy studies

Ref.	Country	Subject number	Key findings
Joo et al[55], 2014	Korea	21	The D* and f values of the treatment group were significantly decreased at four hours. The sizes of the decreases in f and fD* at four hours were negatively correlated with the tumor size at 7 d of follow-up
Wagner et al[56], 2012	France	48	The D values of viable tumor regions in malignant liver tumors were significantly lower than those of necrotic tumor tissue but higher than those of fibrotic tumor regions
Yang et al[57], 2017	China	35	Compared with the values at baseline and those recorded in the control group, the ADC and D values in the treatment group were significantly higher at each time point, whereas the f values decreased significantly at 7 d and increased at 21 d
Lewin et al[58], 2011	France	12	The f values increased significantly in responder patients at two weeks and two months after treatment but decreased in nonresponder patients. The f value was useful as a reliable marker to evaluate sorafenib treatment efficacy in patients with advanced HCC
Shirota et al[59], 2016	Japan	9	The D values at baseline were significantly higher in the responder group than in the nonresponder group. The sensitivity and specificity of the D values for evaluating treatment response were 100% and 67%, respectively

ADC: Apparent diffusion coefficient; HCC: Hepatocellular carcinoma.