1. Radiofrequency ablation combined with hypertonic saline injection allows creation of coagulation zones similar to those created by microwave ablation
Quesada, R., Radosevic, A., Agustí. A., Sanchez, J., Trujillo, M., Berjano, E., Burdío, F.
Disclosures:
This work received financial support from the Spanish “Plan Nacional de I+D+I del Ministerio de Ciencia e Innovación” grant number TEC /TEC. The translation of this paper was funded by the Universidad Politécnica de Valencia, Spain.

2. Purpose
Tumor microwave ablation (MWA)  Coagulation zones larger than radiofrequency ablation (RFA) with internally cooled electrodes (IC) 1.
¿Could IC electrodes combined with hypertonic saline injection create coagulation zones comparable with MWA?

3. Methods and materials Randomized clinical trial: RFA vs MW
AEMPS Nº 438/13/EC, ISRCTN: 30590
Inclusion criteria
HCC or liver metastases (abdominal CT, MRI or biopsy.)
Initial imaging test > 30 days (50 days max)
Considered unresectable hepatic nodules in multidisciplinary and capable local treatment session.
Number of nodules: 1-3
Size of the nodules: cm.
Percutaneous, laparoscopic or open surgical access.
Exclusion criteria
ASA >III
Cardiac pacemaker.
Thrombocytopenia <50,000 / mL.
Suspicion of thrombosis portal by presence of tumor.
Child C
Previous biliodigestive anatomosis

4. Methods and materials
RF: Hybrid applicator: single IC electrode combined with hypertonic saline injection (20% NaCl) through two expandable insulated tubes
Low rate of infusion: 0.5 ml/needle prior and at 1,5 min of the total ablation time
Preclinical experience:
Ablation method:
MW: Amica TM (AGN 3.0 and REF del amica,

5. Results 70 nodules 27 nodules Exclusion: overlapping & pullback
Phase I: June 2014-March 2015; Phase II: April 2015-Feb 2016

6. Results Demographic and clinic description of the patients RF MW p Age
67 ± 2
69 ± 3 NS
Nº of ablations/session
1,4 ± 0,6
1,9 ± 1,3
Max diameter of the lesion (cm)
2,2 ± 0,1
2,2 ± 0,2
Nº of ablations/nodule
1,4 ± 0,1
1,5 ± 0,2
Nº of punctions/nodule
1,5 ± 0,1
1,4 ± 0,1
Type of lesion (HCC/MT)
24/22
19/9
Percutaneous acces ( % (n))
98% (45)
100% (11)
Ascitis ( % (n))
45,7% (21)
64% (18)

7. Results RF MW p Ablation time/nodule (min) 4,1 ± 0,8 4,8 ± 8,6 NS
Deposited energy (kJ) *
40,8 ± 5,1
19,9 ± 8,6
Axial diameter (mm, "D")
37,2 ± 11,8
27,6 ± 6,8
Maximum transverse diameter (mm, "d")
28,0 ± 6,9
Ratio D/d
0,8 ± 0,1
0,7 ± 0,1
* No roll-off case was observed during the RFA.
Similar ablation area in less time (Contrary to Lubner et al. 1)
No differences observed between the heat-sink effect (Contrary to Lloyd et al. 2,3)

8. Results RF MW
Videos of the segmentation process.

9. Results

10. Conclusions Preliminary results:
RF ablation conducted with IC electrode combined with hypersaline injection:
could create coagulation zones similar to MW (equal axial and max transverse diameter).
Similar sphericity of the lesions (ratio D/d)
No correlation between deposited energy and max transversal diameter.

11. References
Lubner MG. Microwave tumor ablation: mechanism of action, clinical results and devices. J Vasc Interv Radiol 2010
Lloyd,DM. International multicenter prospective study on microwave ablation of liver tumour: preliminary results . HBP (Oxford 2011).
Liang P. Microwave ablation of hepatocellular carcinoma. Oncology 2007.