Current oncologic applications of radiofrequency ablation therapies

Table 1 Radiofrequency ablation systems commercially available in the United States[4,8]

RFA system	Electrodes	Generator power/frequency	Control system	Algorithm used to maximize volumes
Boston scientific	14 gauge, 10-12 tines, umbrella shaped	200 W/460 kHz	Impedance controlled	Coaxial system
Valleylab (radionics)	17.5 gauge, single cooled needle or three cooled needles in triangular cluster	200 W/480 kHz	Impedance controlled	Cool-tip
RITA medical systems		250 W/460 kHz	Temperature controlled
Starburst XL	14 gauge, 9 tines, Christmas tree shape max diameter 5 cm			Expandable
Starburst XLi	14 gauge, 9 tines, max diameter 7 cm
Starburst Flex	13 gauge, flexible			Expandable, wet electrode
Berchtold	18-14 gauge	60 W/375 kHz	Impedance or temperature controlled	Wet electrode

Modified from[4,8]. Cool-tip: Cooled electrode achieved with chilled water flowing through electrode but not entering tissue; Wet-electrode: Saline infusion into tissue adjacent to electrode creates larger “virtual” electrode around metal electrode tip.

Table 2 Studies reporting survival after use of radiofrequency ablation for colorectal liver metastases

Ref.	Patients (tumors) n	Median tumor size (cm)	Extrahepatic disease		Chemotherapy	Method	% complete ablation	Local recurrence	Overall survival
									1 yr	3 yr	5 yr
Abdalla et al[26]	57 (110) for RFA	2.5	No	NR	0	NR	9% for RFA	NR	37% for RFA43% for HR + RFA		NR
	190 for HR						5% for HR + RFA		73% for HR
	101 for RFA + HR						2% for HR
Siperstein et al[27]	234 (665)	3.9 (mean)	Yes		80% before RFA	L	NR	NR	NR	20%2	18%2
Park et al[28]	30 for RFA	2.0 for RFA	No		73% after RFA	P	NR	23% for RFA	NR	NR	19%2 for RF1
	59 for HR	3.1 for HR			81% after HR			2% for HR			48%2 for HR
Abitabile et al[54]	47 (147)	2	Yes		After RFA	O, P	97%	9% for overall	88%1	57%1	21%1
								0%-5% for < 3 cm
Gillams et al[55]	167 (167)	3.9 (mean)	Yes		80% before RFA	P	NR	14.00%	99%1	58%1	30%1
									91%2	28%2	25%2
Jakobs et al[56]	68 (183)	2.28 (mean)	No		78% parallel or after	P	NR	18.00%	96%2	71%2
Machi et al[57]	100 (507)	3.0 (mean)	NR			O, L, P		7%	90%	42%	31%
Schindera et al[58]	14 (20)	1.8	No		NR	P	89%	15%	72%2	60%2	NR
White et al[59]	30 (56)	3.0 (0.8-7)	No		36% before, 50% after	P	89%	17%	75%2	45%2	NR
Solbiati et al[60]	117 (179)	2.6	Yes		72% parallel	P	98%	39%	93%2	46%2	NR

¹Calculated from time of diagnosis of liver metastases;

²Calculated after radiofrequency ablation (RFA) treatment of liver metastases. P, L, O: Percutaneous, laparoscopic, open; NR: Not reported; HR: Hazard ratio.

Table 3 Studies involving survival using radiofrequency ablation for primary lung tumors and metastases

Ref.	Patients (tumors) n	Mean tumor size (cm)	Tumor type	Median local progression free interval	Overall survival			Complications
					1 yr	2 yr	3 yr
Ambrogi et al[1]	54 (64)	2.4	40 for NSCLC	< 3 cm - 15.8 mo	72% for NSCLC1	46% for NSCLC1	30% for NSCLC1	6 for PTX
			24 for Mets	> 3 cm - 6.6 mo	88% for Met1	72% for Mets1	NR for Mets1	1 for chest wall hematoma
Kim et al[30]	8 for RFA	3.66 for RFA	All stage I NSCLC	NR	88% for RFA	50% for RFA	25% for RFA	1 for PTX
	14 for SR	3.99 for SR			93% for SR	77% for SR	67% for SR	4 for hemoptysis
Simon et al[35]	153 (189)	2.7	75 for stage I NSCLC	< 3 cm - 45 mo	78% for NSCLC	57% for NSCLC1	36% for NSCLC1	18 for PTX
			57 for Mets	> 3 cm - 12 mo	70% for Met	54% for Mets1	44% for Mets1	5 for hemoptysis
								4 for death
Chua et al[37]	148	4	108 for CRCM	11 mo	NR	NR	60%	66 for PTX
			Other					16 for pleural effusion
			40 for Mets					1 for vleeding
Lencioni et al[61]	106 (183)	3.5	33 for NSCLC	NR	70% for NSCLC	48% for NSCLC		27 for PTX
			73 for Mets		89% for CRCM	66% for CRCM		4 for effusion
					92% for Other	64% for Other
Yan et al[62]	55	2.1	All CRCM	NR	85%	64%	46%	16 for PTX/9 requiring drainage
								5 for hemoptysis
Hiraki et al[63]	20	2.4	All stage I NSCLC	9 mo	90%	84%	74%	13 for PTX/1 requiring drainage

¹Calculated based on Kaplan-Meier survival curves. NR: Not reported; NSCLC: Non-small cell lung cancer; CRCM: Colorectal cancer metastasis; Mets: Other tumor metastases; PTX: Pneumothorax; SR: Surgical resection; RFA: Radiofrequency ablation.

Table 4 Studies involving survival using radiofrequency ablation for primary lung tumors and metastases

Ref.	Patients	Range tumor size (cm)	Mean tumor size (cm)	Complete coagulation necrosis n (%)	Resection	Assessment of cell viability	Complications
Burak et al[38]	10	0.8-1.6	1.2	9 (90)	Delayed	HE CK8/18	None
Singletary et al[40]	29	≤ 2.0	-	25 (86)	Immediate	HE NADH-diaphorase	1 skin burn
Oura et al[41]	52	0.5-2.0	1.3	52 (100)	Delayed	NR	1 skin burn
Khatri et al[64]	15	0.8-1.5	1.28	13 (93)	Immediate	HE NADH-diaphorase	2 skin puckering
Noguchi et al[65]	10	0.5-2.0	1.1	10 (100)	Immediate	HE NADH-diaphorase	None
Fornage et al[66]	20	0.6-2.0	1.2	21 (100)	Immediate	HE NADH-diaphorase	None
Hayashi et al[67]	22	0.5-2.6	0.9 (median)	19 (86)	Delayed	HE NADH-diaphorase	1 skin burn
Izzo et al[68]	26	0.7-3.0	1.8	25 (96)	Immediate	HE NADH-diaphorase	1 skin burn

NR: Not reported; HE: Hematoxylin and eosin stain; NADH: Nicotinamide adenine dinucleotide.

Table 5 Studies involving survival after radiofrequency ablation for solid renal tumors

Ref.	Patients (tumors) n	Method	Mean tumor size (cm)	RCC	Complete first ablation	Recurrence free survival	Overall survival (yr)			Cancer specific survival (yr)		Complications
							1	3	5	3	5
Tracy et al[69]	208 (243)	P, L, O	2.4	79%	97%	90% at 3 yr2	99%1	93%1	85%	95% for RCC	99% for RCC	NR
Levinson et al[70]	31 (34)	P, L	2.1	58%	91%	80% at 5 yr2	NR	NR	63% for all358% for RCC4	NR	100% for all 100% for RCC	4 for perinephric hematoma ; 1 for liver burn; 1 for death from pneumonia
Zagoria et al[71]	41 (48)	P	2.6	100%	NR	88% at 5 yr	NR	NR	66%	NR	NR	2 for pneumothorax no drainage; 2 for ureteral strictures
Stern et al[72]	40	P, L	2.4	81%	97%	91% at 3 yr2	NR	NR	NR	100% for RCC	NR	2 for minor; 3 for major

¹Calculated based on Kaplan-Meier curve and life table;

²In biopsy proven renal cell carcinoma (RCC);

³80 mo overall survival;

⁴57 mo overall survival. P, L, O: Percutaneous, laparoscopic, open; NR: Not reported.