Percutaneous ultrasound-guided radiofrequency ablation for patients with liver metastases from gastrointestinal stromal tumors

Figures & data

Figure 1. Patient selection flow chart. RFA: radiofrequency ablation, GIST: gastrointestinal stromal tumor.

Table 1. The basic characteristics of 34 patients with liver metastasis from GIST.

Characteristics	Patients(n = 34)
Age	52.74 ± 12.8(25-72)
<60	20(58.8%)
≥60	14(41.2%)
Sex
Male	16(47%)
Female	18(53%)
Tumor diameter(cm)	2.4 ± 1.0(1.1-5.2)
≤3	27(79.4%)
>3	7(20.6%)
Tumor number	3.2 ± 2.5(1-12)
≤3	22(64.7%)
>3	12(35.3%)
Primary GIST location
Stomach	19(55.9%)
Non-stomach	15(44.1%)
Metastases location
Difficult	31(91.2%)
No difficult	3(8.8%)
Metastases distribution
Unilobar	18(52.4%)
Multilobar	16(47.6%)
Serum CEA
Detection	24(70.6%)
Normal level	24
Abnormal level	0
No detection	10(29.4%)
Serum CA199
Detection	27(79.4%)
Normal level	26
Abnormal level	1
No detection	7(20.6%)
Extrahepatic metastasis before RFA
Yes	5(14.7%)
No	29(85.3%)
Timing of liver metastasis
Synchronous	15(44.1%)
Metachronous	19(55.9%)
Hepatic resection
Yes	13(38.2%)
No	21(61.8%)
TKI therapy before RFA
Yes	30(88.2%)
PD/SD	11
PR	19
No	4(11.8%)
Mutation analysis
Detection	22(64.7%)
C-KIT mutation	21
Without C-KIT mutation	1
No detection	12(35.3%)
Radical ablation for liver lesions
Yes	23(67.6%)
No	11(32.4%)

Notes: GIST: gastrointestinal stromal tumor; CEA: carcinoembryonic antigen; RFA: radiofrequency ablation; TKI: Tyrosine kinase inhibitors.

Figure 2. Hepatic progression-free survival curves for different tumor number (p = 0.045).

Figure 3. Hepatic progression-free survival curves for patients with or without TKI therapy before RFA (p = 0.014).

Table 2. Univariable and multivariable analyses of the risk factors for HPFS.

	Hepatic-progression-free survival
	1-year	3-year	5-year	univariate analysis
Age				0.659
<60	65.5%	65.5%	13.1%
≥60	68.6%	34.3%	34.3%
Sex				0.159
male	51.9%	51.9%	0%
female	81.5%	67.9%	45.3%
Primary GIST location				0.166
Stomach	71.6%	71.6%	35.8%
Non-stomach	61.9%	49.5%	0%
Maximum dimension of the largest metastasis				0.092
≤3cm	68.9%	68.9%	23.0%
>3cm	50.0%	0%	0%
Number of metastatic tumors				0.045
≤3	58.4%	50.1%	10.0%
>3	100%	100%	100%
Metastases location				0.559
Difficult	69.1%	61.5%	12.3%
No difficult	50.0%	50.0%	50.0%
Metastases distribution				0.150
Unilobar	60.0%	48.0%	0%
Multilobar	77.8%	77.8%	51.9%
Extrahepatic metastasis before RFA				0.109
Yes	33.3%	0%	0%
No	73.0%	64.9%	25.9%
Timing of liver metastasis				0.952
Synchronous	62.2%	62.2%	31.1%
Metachronous	70.7%	60.6%	15.2%
Hepatic resection				0.212
Yes	50.0%	50.0%	50.0%
No	73.7%	64.5%	25.8%
TKI therapy before RFA				0.014
Yes	76.7%	69.0%	23.0%
No	25.0%	25.0%	25.0%

Notes: GIST: gastrointestinal stromal tumor; RFA: radiofrequency ablation; TKI: Tyrosine kinase inhibitors.

Table 3. Multivariate analysis of HPFS factors with Cox proportional hazards in patients with liver metastasis from GIST after RFA.

	Hazard ratio	Standard error	Wald value	p value	95% confidence interval
TKI therapy before RFA	0.025	1.713	4.688	0.030	0.001-0.704

Notes: GIST: gastrointestinal stromal tumor; RFA: radiofrequency ablation; TKI: Tyrosine kinase inhibitors.

Figure 4. Overall survival curves for patients with or without extrahepatic metastasis before RFA (p = 0.044).

Figure 5. Images from a 60-year-old male with liver metastasis from GIST. (A) Ultrasound before RFA showed a 1.6 cm tumor in liver. (B) Contrast-enhanced ultrasound before RFA showed a 1.8 cm tumor with slight enhancement in liver. (C)MRI showed a 1.8 cm enhanced tumor (arrow) in liver. (D) with ultrasound guidance, two bipolar RFA electrodes (arrow) were inserted into the tumor (E)Contrast-enhanced CT one month after initial RFA showed ablation area showed ablation area had no viability. (F) Contrast-enhanced CT 6 months after initial RFA showed ablation area shrunk without local progression or new liver metastases.

Table 4. Univariable analyses of the risk factors for OS.

	Survival rate
	1-year	3-year	5-year	univariate analysis
Age				0.207
<60	94.4%	87.7%	68.2%
≥60	100%	57.1%	42.9%
Sex				0.810
Male	100%	75.0%	56.3%
Female	93.8%	79.8%	63.8%
Primary GIST location				0.906
Stomach	94.4%	83.0%	59.4%
Non-stomach	100%	62.2%	62.2%
Maximum dimension of the largest metastasis				0.333
≤3cm	100%	78.2%	68.4%
>3cm	85.7%	71.4%	42.9%
Number of metastatic tumors				0.439
≤3	100%	70.8%	70.8%
>3	90.9%	90.9%	22.7%
Metastases location				0.215
Difficult	96.6%	74.0%	53.8%
No difficult	100%	100%	100%
Metastases distribution				0.818
Unilobar	93.8%	76.7%	67.1%
Multilobar	100%	76.4%	50.7%
Extrahepatic metastasis before RFA				0.044
Yes	100%	86.2%	63.9%
No	100%	75.6%	56.0%
Timing of liver metastasis				0.523
Synchronous	100%	77.8%	41.5%
Metachronous	94.7%	75.8%	66.3%
Hepatic resection				0.372
Yes	100%	68.2%	36.4%
No	95.0%	83.1%	72.7%
TKI therapy before RFA				0.262
Yes	96.4%	72.8%	47.2%
No	100%	100%	100%

Notes: GIST: gastrointestinal stromal tumor; RFA: radiofrequency ablation; TKI: TYROSINE kinase inhibitors.

Table 5. Multivariate analysis of OS factors with Cox proportional hazards in patients with liver metastasis from GIST after RFA.

	Hazard ratio	Standard error	Wald value	p value	95% confidence interval
Extrahepatic metastasis before RFA	32.434	1.731	4.038	0.044	1.089–965.612

Data availability statement

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.