Page 247 - Read Online

As reported by the authors, the study has some limitations. Financial support and sponsorship
First, it is a retrospective non-randomized study. Second, all Nil.
the treatments were performed by using MWA. Therefore, a
comparison with other thermal techniques is not possible. Conflicts of interest
Finally, long-term outcome would also require longer follow- There are no conflicts of interest.
up times. However, as stated by the authors, this study was
intended to be a pilot report on the treatment of larger HCC REFERENCES
by using MWA.
Surgical resection and RFA can actually achieve the same 1. Bruix J, Sherman M; Practice Guidelines Committee, American
Association for the Study of Liver Disease. Management of
good results in the treatment of very-early HCC (≤ 2 hepatocellular carcinoma. Hepatology 2005;42:1208-36.
cm). Surgical resection remains the gold standard for the 2. Yao FY, Bass NM, Nikolai B, Davern TJ, Kerlan R, Wu V, Ascher NL,
treatment of early (< 3 cm) HCC, although RFA represents Roberts JP. Liver transplantation for hepatocellular carcinoma: analysis
an effective alternative in patients who are not eligible for of survival according to the intention-to-treat principle and dropout from
surgery. Based on the BCLC guidelines, single nodules from 3 3. the waiting list. Liver Transplant 2002;8:873-83.
Gervais DA, Goldberg SN, Brown DB, Soulen MC, Millward SF,
to 5 cm are classified as intermediate HCC, and transarterial Rajan DK. Society of Interventional Radiology position statement on
chemoembolisation (TACE) is recommended as the best percutaneous radiofrequency ablation for the treatment of liver tumors.
treatment option. Nevertheless, most experts consider J Vasc Interv Radiol 2009;20:S342-7.
[5]
surgery the very best option for the treatment of resectable 4. McCarley JR, Soulen MC. Percutaneous ablation of hepatic tumors.
large nodules with curative intent. However, most patients 5. Semin Intervent Radiol 2010;27:255-60.
Bruix J, Sherman N; American Association for the Study of Liver
with intermediate HCC are not eligible for surgery because Diseases. Management of hepatocellular carcinoma: an update.
of inadequate liver function, anatomic limitations, multifocal Hepatology 2011;53:1020-2.
disease, or medical comorbidities. This group of patients 6. Peng ZW, Lin XJ, Zhang YJ, Liang HH, Guo RP, Shi M, Chen MS.
can benefit from TACE, or combined treatments including Radiofrequency ablation versus hepatic resection for the treatment of
RFA plus TACE. RFA alone is frequently unable to obtain an hepatocellular carcinoma 2 cm or smaller: a retrospective comparative
adequate safety margin in nodules > 3 cm, particularly when 7. study. Radiology 2012;262:1022-33.
Tombesi P, Di Vece F, Sartori S. Resection vs. thermal ablation of
the tumor is strictly close to large vessels, because thermal small hepatocellular carcinoma: what’s the first choice? World J Radiol
energy is partially shunted away by the cooler blood (the so- 2013;5:1-4.
called heat-sink effect). [9,10] Moreover, the treatment of large 8. Thamtorawat S, Hicks R, Yu J, Siripongsakun S, Lin WC, Raman S,
nodules require multiple overlapping insertions of the needle McWilliams JP, Douek M, Bahrami S, Lu DSK. Preliminary outcome
electrode, and it is known that the insertions following the of microwave ablation of hepatocellular carcinoma: breaking the 3-cm
barrier? J Vasc Interv Radiol 2016;27:623-30.
first or second ones can be inaccurate owing to the steam 9. Mulier S, Jamart J, Ruers T, Marchal G, Michel L. Local recurrence
generated during the procedure. As a consequence after hepatic radiofrequency coagulation: multivariate meta-analysis
[11]
of these limitations, at present the use of RFA alone with and review of contributing factors. Ann Surg 2005;242:158-71.
curative intent is limited to nodules up to 3 cm. 10. Lu DS, Raman SS, Limanond P, Aziz D, Economou J, Busuttil R, Sayre
J. Influence of large peritumoral vessels on outcome of radiofrequency
Several studies demonstrated that last generation MWA ablation of liver tumors. J Vasc Interv Radiol 2003;14:1267-74.
systems enable to achieve larger ablation volumes than RFA, 11. Di Vece F, Tombesi P, Ermili F, Maraldi C, Sartori S. Coagulation areas
with comparable safety and survival rates. [12-16] A randomized produced by cool-tip radiofrequency ablation and microwave ablation
prospective comparison of MWA and RFA in the treatment using a device to decrease back-heating effects: a prospective pilot
study. Cardiovasc Intervent Radiol 2014;37:723-9.
of HCC did not demonstrate any difference in the rates of 12. Lu MD, Xu HX, Yin XY, Chen JW, Kuang M, Xu ZF, Liu GJ,
residual or untreated disease, and the capability of MWA Zheng YL. Percutaneous microwave and radiofrequency ablation
[17]
to produce larger coagulation areas could result particularly for hepatocellular carcinoma: a retrospective comparative study. J
useful in the treatment of tumors ≥ 3 cm. Reported mortality Gastroenterol 2005;40:1054-60.
and major complication rates using the most recent MWA 13. Simon CJ, Dupuy DE, Mayo-Smith WW. Microwave ablation principles
and applications. Radiographics 2005;25 Suppl 1:S69-83.
devices are similar to RFA. Complication rates reported 14. Boutros C, Somasundar P, Garrean S, Saied A, Espat NJ. Microwave
[18]
by Thamtorawat et al. agree with the data reported by coagulation therapy for hepatic tumors: review of the literature and
[8]
other authors, despite the larger size of the treated nodules. critical analysis. Surg Oncol 2010;19:e22-32.
Moreover, although MWA appears less feasible than RFA in 15. Lubner MG, Brace CL, Ziemlewicz TJ, Hinshaw JL, Lee FT Jr.
the treatment of high-risk located and subcapsular nodules, Microwave ablation of hepatic malignancy. Semin Intervent Radiol
2013;30:56-66.
no difference in local tumor progression rate was found for 16. Qian GJ, Wang N, Shen YH, Zhao JQ, Kuang M, Liu GJ, Wu MC.
subcapsular nodules in the study of Thamtorawat et al. [8] Efficacy of microwave versus radiofrequency ablation for treatment of
small hepatocellular carcinoma: experimental and clinical studies. Eur
In conclusion, in our opinion this article could be considered Radiol 2012;22:1983-90.
the starting point for breaking the 3-cm barrier in the 17. Shibata T, Iimuro Y, Yamamoto Y, Ametani F, Itoh K, Konishi J.
treatment of non surgical HCC. Our preliminary experience Small hepatocllular carcinoma: comparison of radio-frequency
in the treatment of large nodules supports the efficacy ablation and percutaneous microwave coagulation therapy. Radiology
of MWA for HCC up to 5 cm (unpublished data), and we 2002;223:331-7.
hopefully expect further studies with longer follow-up aimed 18. Livraghi T, Meloni S, Solbiati L, Zanus G; Collaborative Italian Group
using AMICA System. Complications of microwave ablation for liver
at extending the dimensional barrier of thermal ablation tumors: results of a multicenter study. Cardiovasc Intervent Radiol
with curative intent. 2012;35.868-74.
238 Hepatoma Research | Volume 2 | August 25, 2016