Current status and future perspectives of radiomics in hepatocellular carcinoma

Table 5 Summary of the studies that assessed reproducibility of hepatocellular cholangiocarcinoma textural features

Ref.	Country	n	Imaging modality	Segmentation	Segmentation software	ROI/VOI	No. of readers	Intra-reader reproducibility	Inter-reader reproducibility	Other reproducibility
Duan et al[88], 2022	China	19	CT, MRI	Manual, intra- and peritumoral	3D-Slicer	ROI	2 (1 radiologist and 1 radiation oncologist)	Features with ICC ≥ 0.75 in both tumoral and peritumoral tissue greatest in MR	Features with ICC ≥ 0.75 in both tumoral and peritumoral tissue greatest in MR	N/A
Zhang et al[102], 2022	China	90 (31 HCC)	MRI	Manual, intratumoral	ITK-SNAP	ROI and VOI	2 radiologists	N/A	ICC > 0.8 used	N/A
Carbonell et al[89], 2022	United States	55 (16 HCC)	MRI	Manual, intratumoral and liver parenchyma	Olea sphere 3.0, Olea Medical	ROI for normal liver, VOI for HCC	2 radiologists	N/A	CCC: 0.80-0.99	For test-retest (same MRI system, 2 different MRI exams): ICC: 0.53-0.99; and in liver parenchyma: ICC: 0.53-0.73. For inter-platform reproducibility (MRI systems from 2 different vendors): CCC: 0.58-0.99
Park et al[103], 2022	South Korea	249	CT	Manual followed by automatic segmentation, intratumoral	MEDIP PRO	ROI and VOI	1 radiologist	For VOI: Manual: ICC 0.594-0.998 for FO, 0.764-0.997 for shape, and 0.190-0.926 for SO; DL-AS: ICC > 0.75 for all. For ROI: Manual: 0.698-0.997 for FO, 0.556-0.997 for shape, and 0.341-0.935 for SO; DL-AS ICC > 0.75 for all	N/A
Haniff et al[104], 2021	Malaysia	30	MRI	Manual and semi-automatic, intratumoral	3D-Slicer	VOI	Manual: 4 readers. Semi-automatic: 2 readers	N/A	Manual segmentation: ICC 0.897. Semi-automatic segmentation: ICC 0.952	NA
Ibrahim et al[90], 2021	Germany	61 patients, 104 lesions	CT	Manual, intratumoral	MIM software	ROI	1 nonradiologist revised by radiologist	N/A	N/A	Across different contrast imaging phases: 25% of extracted features had CCC > 0.9 across arterial and portal venous phases
Hu et al[105], 2021	China	30	CT	Manual, intratumoral	MaZda software	ROI	2 radiologists	ICC > 0.7	ICC > 0.7	N/A
Mao et al[32], 2020	China	30	CT	Manual, intratumoral	ITK-SNAP	ROI	2 radiologists	N/A	ICC ≥ 0.8	N/A
Hu et al[106], 2020	China	50	CT	Semi-automatic, peritumoral	Not mentioned	ROI	2 radiologists	N/A	ICC > 0.6	N/A
Qiu et al[107], 2019	China	26	CT	Manual and semi-automatic, intratumoral	GrowCut and GraphCut	ROI	Manual: 5 radiation oncologists. Semi-automatic: 2 radiation oncologists	N/A	ICC ≥ 0.75 in 69% of features extracted from manual segmentation, 73% from GraphCut, and 79% from GrowCut	Across different centers: Poor reproducibility of CT-based peritumoral-radiomics model
Zhang et al[108], 2019	China	46 (34 HCC)	MRI	Manual, intratumoral	MIM software	VOI	1 radiologist	N/A	N/A	Across different b-values: radiomic features extracted from b = 0, 20, 50, 100, 200 s/mm2 and b = 1000 s/mm2 and nearby b-values DWIs showed a high reproducibility (ICC ≥ 0.8)
Feng et al[40], 2019	China	160 (110)	MRI	Manual, intra- and peritumoral	ITK-SNAP	VOI	3 radiologists	85% ICC ≥ 0.8	82% ICC ≥ 0.8	N/A
Perrin et al[91], 2018	United States	38 (6 HCC)	CT	Semi-automatic, intratumoral and liver parenchyma	Scout Liver	VOI	1 research fellow under supervision of radiologist	N/A	N/A	Across different contrast injection rates, pixel resolutions, and scanner models: Number of reproducible radiomic features (CCC > 0.9) decreased with variations in contrast injection rate, pixel resolution, and scanner model

CT: Computed tomography; MRI: Magnetic resonance imaging; ROI: Region of interest; VOI: Volume of interest; TACE: Transarterial chemoembolization; ICC: Intraclass correlation coefficient; DWI: Diffusion-weighted imaging; CCC: Concordance correlation coefficient; HCC: Hepatocellular carcinoma; N/A: Not applicable; FO: First order; SO: Second order; DL-AS: Deep learning-based auto-segmentation.