Multibipolar radiofrequency vs single needle microwave ablation for the treatment of newly diagnosed hepatocellular carcinoma

Table 1 Baseline characteristics of the patient cohort (n = 362) used for analysis of secondary outcomes and the nodules cohort (n = 436) used to assess local tumor progression, n (%)

Characteristics	Patients (n = 362)			Nodules (n = 436)
	MWA (n = 120)	Mbp-RFA (n = 242)	P value	MWA (n = 147)	Mbp-RFA (n = 289)	P value
Age in years (IQR)	65.52 (59.1-71.7)	66.33 (59.3-72.2)	P = 0.81
Male	97 (80.8)	211 (87.2)	P = 0.11
Cirrhosis	117 (97.5)	226 (93.4)	P = 0.1
Cirrhosis aetiologies
Viral hepatitis	19 (15.8)	44 (18.2)	P = 0.91
NASH	23 (19.2)	44 (18.2)
Alcoholic	41 (34.2)	74 (30.6)
Other/mixed	20 (16.7)	39 (16.1)
Child Pugh
Child Pugh A	99 (82.5)	211 (87.2)	P = 0.23
Child Pugh B	21 (17.5)	31 (12.8)
Platelet count
< 100 G/L	47 (39.2)	82 (33.9)	P = 0.32
≥ 100 G/L	73 (60.8)	160 (66.1)
AFP
< 10 ng/mL	86 (71.7)	159 (65.7)	P = 0.39
10-100 ng/mL	27 (22.5)	60 (24.8)
> 100 ng/mL	7 (5.8)	23 (9.5)
Number of nodules treated per patient	1.41	1.34	P = 0.16
Histological proof	41 (34.2)	198 (81.8)	P < 0.005
Size
< 20mm				69 (46.9)	93 (32.2)	P < 0.001
20-30 mm				55 (37.4)	108 (37.4)
≥ 30 mm				23 (15.6)	88 (30.4)
Tumour near large vessel				20 (13.6)	36 (12.5)	P = 0.735
Subcapsular tumour				74 (50.3)	167 (57.8)	P = 0.139
Proximity to the gallbladder				4 (2.7)	18 (6.2)	P = 0.114
Segmental portal thrombosis				0	3 (1)	P = 0.554
Operator experience (months)				107 (38-360)	303 (105-331)	P = 0.026
Guidance modality
By ultrasound alone				49 (33.3)	288 (99.7)	P < 0.001
By scanner alone				7 (4.8)	1 (0.3)
Mixed guidance (ultrasound + scanner)				91 (61.9)	0
Nodules treated per center						P < 0.001
Institution A				35 (23.8)	289 (100)
Institution B				112 (76.2)	0 (0)

Mbp-RFA: Multibipolar radiofrequency ablation; MWA: Microwave ablation; IQR: Interquartile range; NASH: Non-alcoholic steatohepatitis; AFP: Alpha-fetoprotein.

Table 2 Residual tumor and local recurrence rates as a function of lesion size and treatment group, n (%)

	Residual tumor (n = 491 nodules)		Local tumor progression (n = 436 nodules)
Total	MWA (n = 168)	21 (12.5)	MWA (n = 147)	37 (25.2)
	Mbp-RFA (n = 323)	19 (5.9)	Mbp-RFA (n = 289)	33 (11.4)
	P value	0.01	P value	0.002
< 30 mm	MWA (n = 141)	17 (12.1)	MWA (n = 124)	23 (18.5)
	Mbp-RFA (n = 227)	15 (6.6)	Mbp-RFA (n = 201)	17 (7)
	P value	0.071	P value	< 0.002
≥ 30 mm	MWA (n = 27)	4 (14.8)	MWA (n = 23)	14 (60.9)
	Mbp-RFA (n = 96)	4 (4.2)	Mbp-RFA (n = 88)	19 (21.6)
	P value	0.069	P value	0.04

Mbp-RFA: Multibipolar radiofrequency ablation; MWA: Microwave ablation.

Table 3 Predictive factors of local recurrence (n = 436 nodules)

	Univariable analysis		Multivariable analysis		Multivariable analysis (competing risks)
	HR (95%CI)	P value	HR (95%CI)	P value	HR (95%CI)	P value
Age (years)	1.03 (1.002-1.06)	0.037	1.02 (0.99-1.05)	0.192	1.02 (0.98-1.06)	0.15
Sex (male vs female)	0.62 (0.31-1.25)	0.182	-	-	-	-
Child Pugh (B vs A)	1.85 (0.94-3.65)	0.074	1.55 (0.75-3.2)	0.233	0.72 (0.27-1.95)	0.52
Platelet count (for 50.000 additional platelet)	1.09 (0.90-1.33)	0.376	-	-	-	-
AFP (for 100 ng/mL additional)	1.10 (1.08-1.13)	< 0.001	1.05 (0.99-1.11)	0.080	1 (0.94-1.01)	0.48
Tumor size (mm)	1.08 (1.06-1.11)	< 0.001	1.08 (1.05-1.11)	< 0.001	1.07 (1.05-1.1)	0.06
Subcapsular HCC	0.97 (0.60-1.57)	0.900	-	-	-	-
Proximity of HCC to large vessels	1.29 (0.68-2.42)	0.435	1.34 (0.69-2.59)	0.393	1.14 (0.59-2.2)	0.7
Number of HCC nodules	0.88 (0.71-1.08)	0.224	-	-	-	-
Treatment by ultrasound guidance alone	0.40 (0.10-1.59)	0.193	-	-	-	-
Treatment by ultrasound and CT guidance	0.92 (0.22-3.79)	0.908	-	-	-	-
Operator experience (per additional month)	1.00 (0.998-1.002)	0.963	1.00 (0.999-1.002)	0.702	1.00 (0.999-1)	0.9
Thermoablation technique (MWA vs mbp-RFA)	2.41 (1.48-3.90)	< 0.001	2.85 (1.69-4.81)	< 0.001	2.35 (1.3-4.3)	0.005

HR: Hazard ratio; CI: Confidence interval; AFP: Alpha-fetoprotein; HCC: Hepatocellular carcinoma; CT: Computed tomography; MWA: Microwave ablation; mbp-RFA: Multibipolar radiofrequency ablation.

Table 4 Major complications according to the society of interventional radiology classification (n = 362 patients)

Society of interventional radiology classification	Treatment group
	MWA, n = 9 (7.5%)	Mbp-RFA, n = 23 (9.5%)
Grade C	4 (3.3%): 2 patients with portal thrombus requiring anticoagulation; 2 patients with symptomatic undrained pleural effusion	9 (3.7%): 3 patients with portal thrombus requiring anticoagulation; 2 patients with symptomatic undrained pleural effusion; 1 patient with ascitic decompensation treated with diuretics; 2 patients with pneumopathy treated with antibiotics; 1 patient with soft tissue hematoma with pain
Grade D	4 (3.3%): 2 patients with symptomatic pleural effusion with indication for pleural drainage; 1 patient with cessation of the procedure after treatment of the first nodule for dyspnea, transfer to intensive care; 1 patient with drained pneumothorax	13 (5.4%): 8 patients with symptomatic pleural effusion with indication for pleural drainage; 2 patients with reactive cholecystitis (1 operated, 1 medically treated); 1 patient with an arterio-portal fistula requiring remote embolization; 2 patients with an infection of the surgical site (one with pre-hepatic collection, on with intra-hepatic collection in contact with the scar)
Grade E	1 (0.8%): 1 patient with necrosis of the left lobe with stay in intensive care	1 (0.4%): 1 biliopleural fistula requiring drainage and thoracoscopy
Grade F	0	0

MWA: Microwave ablation; Mbp-RFA: Multibipolar radiofrequency ablation.