Percutaneous thermal ablation for the treatment of colorectal liver metastases and hepatocellular carcinoma: a comparison of local therapeutic efficacy

Figures & data

Figure 1. Flow chart of the present study. Random assignment was performed using SPSS version 19.0. MLC: metastatic liver carcinoma; TACE: transcatheter arterial chemoembolization; MWA: microwave ablation; RFA: radiofrequency ablation; CRLM: colorectal liver metastases; HCC: hepatocellular carcinoma.

Table 1. Clinical characteristics of CRLM and HCC patients.

Characteristic	CRLM group	HCC group	p values
Patient data
No. of cases	101	97
Sex (M/F)	64/37	84/13	<0.001
Age*	58.2 ± 12.4 (28.0 ∼ 83.0)	54.0 ± 11.6 (27.0 ∼ 81.0)	0.216
Prior liver resection (yes/no)	25/76	60/37	<0.001
Prior systemic chemotherapy(yes/no)	44/57	NA	NA
Lesion/tumour profile
Number	161	122	NA
Diameter (cm)*	2.1 ± 1.0 (0.7 ∼ 6.0)	2.3 ± 1.1 (0.8 ∼ 7.0)	0.089
No. of lesions ≤ 3 cm/> 3 cm	138/23	93/29	0.041
Follow-up time (months)*	21.1 ± 20.7 (1 ∼ 89.6)	22.1 ± 17.6 (1 ∼ 71.6)	0.612

CRLM: colorectal liver metastases; HCC: hepatocellular carcinoma; NA: not applicable.

* Values represent continuous data, presented as the means ± SDs. The numbers in parentheses are the ranges.

Table 2. Comparison of local therapeutic efficacy in the CRLM and HCC groups.

	Lesions ≤3 cm		Lesions >3 cm		All lesions
	CA rates	LTP rates	CA rates	LTP rates	CA rates	LTP rates
CRLM	90.0% (124/138)	20.2% (25/124)	82.6% (19/23)	57.9% (11/19)	88.8% (143/161)	25.2% (36/143)
HCC	97.9% (92/94)	17.4% (16/92)	82.1% (23/28)	17.4% (4/23)	94.3% (115/122)	17.4% (20/115)
p values	0.018	0.526	1.000	0.036	0.110	0.132

CRLM: colorectal liver metastases; HCC: hepatocellular carcinoma; CA: complete ablation; LTP: local tumour progression.

Figure 2. Curves of local tumour progression (LTP), calculated by the Kaplan–Meier method, according to tumour size (≤ 3 cm/> 3 cm). (a) The log-rank test demonstrates that over time, the presence of tumour size >3 cm was associated with a significantly higher rate of LTP in the CRLM group (p = 0.002). (b) The log-rank test demonstrates that over time, the presence of tumour size >3 cm was not associated with LTP in the HCC group (p = 0.979).

Figure 3. Curves of local tumour progression (LTP), calculated by the Kaplan–Meier method, according to safety margin (≤ 0.5 cm/> 0.5 cm). (a) and (b), The log-rank test demonstrates that over time, the presence of a safety margin ≤0.5 cm was associated with a significantly higher rate of LTP in the CRLM and HCC group (p < 0.001, p = 0.013).

Figure 4. HCC in a 57-year-old patient. (a) The image obtained by CECT before thermal ablation indicates a lesion diameter of 4.1 cm in segment VIII, with hyper-enhancement in the arterial period (arrow). (b) One month after thermal ablation, the ablated area did not exhibit enhancement in CECT (arrow), which confirms complete ablation of the tumour. The diameter of the ablated area was 4.2 cm. We calculated a safety margin of 0 cm. (c) and (d) Approximately 7.1 months after ablation, the arterial phase in CECT revealed nodular hyper-enhancement at the lateral margin of the ablated area, which indicates LTP (arrow); washout of this nodule was observed in the portal venous phase of CECT.

Table 3. Univariate analysis of risk factors for LTP in CRLM and HCC after ablation.

Variable	LTP in CRLMgroupp values	LTP in HCCgroupp values
Gender (male)	0.752	0.216
Age (> 65 years)	0.885	0.932
Hepatitis B/C virus (+/−)	0.002	0.881
Child-Pugh class (A/B)	0.832	0.326
Serum ALT level (>40 U/L)	0.825	0.284
Serum total bilirubin (>34.2 mg/dl)	0.956	0.945
Serum albumin (>40 g/l)	0.238	0.688
Prothrombin time (>14 s)	0.250	0.035
Tumour size (≤3 cm/>3 cm)	0.002	0.979
Prior liver resection (yes/no)	0.305	0.225
Prior systemic chemotherapy(yes/no)	0.111	NA
Systemic chemotherapy after ablation(yes/no)	0.413	NA
TACE after ablation (yes/no)	NA	0.791
Type of thermal ablation (MWA/RFA)	0.026	0.969
Safety margin (≤0.5 cm/>0.5 cm)	<0.001	0.013

ALT: alanine aminotransferase; CRLM: colorectal liver metastases; HCC: hepatocellular carcinoma; LTP: local tumour progression; NA: not applicable.

Table 4. Multivariate analysis of risk factors for LTP in CRLM and HCC after ablation.

Variables	p values	Risk ratio(95% confidenceinterval)
CRLM
Hepatitis B/C virus (+/−)	0.714	NA
Tumour size (≤3 cm/> 3 cm)	0.458	NA
Margin size (≤0.5 cm/> 0.5 cm)	0.018	0.066 (0.023–0.191)
Type of thermal ablation (MWA/RFA)	0.622	NA
HCC
Prothrombin time (>14 s)	0.982	NA
Tumour size (≤3 cm/>3 cm)	0.447	NA
Margin size (≤0.5 cm/>0.5 cm)	0.022	0.174 (0.052–0.579)

LTP: local tumour progression; CRLM: colorectal liver metastases; HCC: hepatocellular carcinoma; NA: not applicable