Intraprocedural contrast-enhanced ultrasound-CT/MR fusion imaging assessment in HCC thermal ablation to reduce local tumor progression: compared with routine contrast-enhanced ultrasound

Figures & data

Figure 1. A case using CEUS-MR fusion imaging for intraprocedural treatment response assessment. (a) shows the co-registration process: a1 shows the overlapped US and MR images; the left branch of the portal vein is chosen as an anatomical landmark; a2 shows the corresponding MR image. (b) shows the first CEUS-MR fusion imaging assessment: b1 shows the overlapped CEUS and MR images after the administration of the contrast agent; AM is inadequate (arrow); b2 shows the corresponding MR image with the tumor outlined in blue and the AM in purple. (c) shows the process of supplementary ablation: c1 shows that the electrode is inserted to the site of inadequate AM (arrow) under the guidance of US-MR fusion imaging; c2 shows the corresponding MR image. (d) shows the second CEUS-MR fusion imaging assessment: d1 shows the overlapped CEUS and MR images; adequate AM is obtained (arrow) after the supplementary ablation; d2 shows the corresponding MR image.

Table 1. Reasons for failure in CEUS-CT/MR fusion imaging assessment.

Reasons	Number of patients, n (%)
Severe liver cirrhosis and limited acoustic window	1 (6.25)
Anatomical structure deformation	13 (81.25)
Hydrodissection	3 (18.75)
Open surgeries	7 (43.75)
Lateral position adopted in the procedure	3 (18.75)
Unknown reason (magnetic field interference suspected)	2 (12.5)
Total	16 (100)

‘Hydrodissection’ refers to the creation of artificial ascites or right pleural effusion. ‘Open surgeries’ includes liver lobe resection, gall bladder resection and para-liver adhesion separation.

Table 2. Baseline characteristics of study population.

Characteristic	Value		p value
	Fusion imaging group	Routine CEUS group
Age (years)	53.6 ± 10.4 (29–75)^a	53.8 ± 9.9 (30–71)^a	.935
Sex (male/female)	91/7	83/9	.513
HBV or HCV (yes/no)	97/1	90/2	.611
Liver cirrhosis (yes/no）	82/16	79/13	.674
Child-Pugh classification (A/B)	89/9	77/15	.140
AFP (<200 ng/ml/≥200 ng/ml)	88/10	76/16	.150
Number of lesion (single/multiple)	75/23	67/25	.557
Tumor diameter (mm)	19.6 ± 7.7 (10–52)^a	21.5 ± 10.3 (10–60)^a	.105
Tumor diameter ≥30 mm (yes/no)	17/109	21/99	.385
Tumor close to large vessels (yes/no)	32/94	38/82	.276
Ablation method (RFA/MWA)	94/4	90/2	.683
TACE (yes/no)	41/85	44/76	.496
History of HCC treatment (yes/no)	54/72	62/58	.166

^a Mean ± SD (range).

‘HBV’ refers to hepatitis B virus. ‘HCV’ refers to hepatitis C virus. ‘Liver cirrhosis’ was diagnosed according to biopsy, clinical presentation and imaging examination. ‘AFP’ refers to alpha-fetoprotein.

Table 3. Reasons for inadequate AM in CEUS-CT/MR fusion imaging group.

Reasons	Number of lesions, n (%)
The tumor was adjacent to large vessels	32 (74.4)
The tumor was adjacent to critical structures	7 (16.3)
Large tumor size or relatively insufficient hepatic function reserve	2 (4.6)
Others	2 (4.7)
Total	43 (100)

‘Large vessels’ refer to vessels in the liver with a diameter larger 3 mm. ‘Critical structures’ refer to diaphragm, gastrointestinal tract, gall bladder and first hepatic portal (for the protection of biliary system). ‘Others’: for one lesion (located in segment VIII, adjacent to the second hepatic portal), the long puncture path and the vessel obstacles on the path made the re-puncture difficult; for the other one, re-puncture was canceled because of the unstable vital signs of the patient during the operation.

Figure 2. Cumulative local tumor progression rate curves. (a) Cumulative local tumor progression rate curves of lesions with adequate and inadequate AM in fusion imaging group. The difference was significant by the first 21 months (p = .028) but was not significant as a whole (p = .447). (b) Cumulative local tumor progression rate curves of two groups. The difference was not significant as a whole (p = .316). (c) Cumulative local tumor progression rate curves of lesions of two groups that didn’t receive TACE therapy 1–2 weeks before ablation. The difference was not significant as a whole (p = .549). (d) Cumulative local tumor progression rate curves of lesions of two groups that received TACE therapy 1–2 weeks before ablation. The difference was significant as a whole (p = .032).

Table 4. Cumulative local tumor progression rate of each year.

	Lesions with adequate AM (%)	Lesions with inadequate AM (%)	p value	Fusion imaging group (%)	Routine CEUS group (%)	p value
1 year	2.6	13.6	.028	6.2	5.7	.881
2 years	4.3	13.6	.073	7.3	8.6	.795
3 years	6.3	13.6	.153	8.5	10.1	.748
4 years	6.3	13.6	.153	8.5	11.7	.558
5 years	13.0	13.6	.447	12.4	18.0	.399

Values are presented as cumulative local tumor progression rate of each year in different groups and subgroups; p values show difference between the corresponding groups and subgroups for each year.

Figure 3. Overall survival rate curves. (a) Overall survival rate curves of two groups. The difference was not significant as a whole (p = .892). (b) Overall survival rate curves of patients of two groups that received TACE therapy 1–2 weeks before ablation. The difference was not significant as a whole (p = .901).

Table 5. Overall survival rate of each year.

	Fusion imaging group (%)	Routine CEUS group (%)	p value
1 year	95.7	96.4	.843
2 years	93.5	93.8	.951
3 years	89.8	93.8	.422
4 years	88.4	91.9	.484
5 years	88.4	87.9	.892

Values are presented as overall survival rate of each year in different groups; p values show difference between the corresponding groups for each year.