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feasible than RFA in the treatment of high-risk located and difficult, particularly if more than two fibers are needed and
subcapsular nodules. In addition, MWA is more expensive should be performed by very skilled operators. The efficacy of
than RFA and LTA. LTA can be limited by the heat-sink effect.

LASER ABLATION FINAL CONSIDERATIONS

LTA utilizes laser devices that convert electrical into light Surgical resection is the treatment of choice for LM,
energy, which determines tissue heating and cellular death and liver transplantation, whenever possible, is the best
by coagulative necrosis. Neodymiun: Yttrium aluminum curative option for HCC. However, in recent years thermal
garnet (wavelength of 1,064 nm) and diode (wavelength of ablation therapies have become more and more central in
800-980 nm) lasers are most commonly used, as penetration the treatment of liver lesions, as the majority of patients
of light is optimal in the near infrared spectrum. Light is are not eligible for surgery. Moreover, some recent studies
delivered via flexible bare tip fibers with a diameter from suggested that RFA is as effective as surgical resection, or
300 to 600 μm. A bare-tip fiber provides an almost spherical even preferable in selected patients, in the treatment of
thermal lesion of 12-15 mm in diameter, and a beam-splitting small HCC lesions. [11,12] Good local tumor control and survival
device or a multi-source device allows the use of up to four comparable with surgical resection were also reported in
fibers, simultaneously delivering the light into each single subgroups of patients with LM from colorectal and breast
fiber. [15-17] The optical and thermal characteristics of the tissue, cancer. [18,19] Thermal ablation of HCC in patient waiting
as well as the proximity of blood vessels, determine the for liver transplantation can be performed as a bridge to
thermal diffusion of the light energy and define the ablation the transplantation. Likewise, thermal ablation combined
area. Bare tip fibers are inserted through 21-gauge needles with resection and/or systemic chemotherapy has been
into the lesions. Usually, one to two fibers are used to treat demonstrated to improve the survival in patients with LM.
nodules up to 1.5 cm in diameter, three fibers to treat nodules
from 1.5 to 2.5 cm, and four fibers with tips arranged in a Thermal therapies are minimally invasive, well tolerated, and
square configuration to treat nodules > 2.5 cm. In addition, demonstrate a very low rate of major complications. Although
the pullback technique can be used to treat larger nodules. RFA represents the “historical” and more experienced
thermal ablation technique, both MWA and LTA have been
LTA has been investigated less vigorously than the other demonstrated to be as effective and safe as RFA when
ablation techniques, but it seems to show the same efficacy performed by skilled operators. [13-16] Therefore, to date in most
and safety profile than RFA, with a shorter treatment time per centers of interventional oncology or interventional radiology
session. [16,17,41-43] Most of the studies on LTA are focused on the choice of the ablation technique usually depends on the
the treatment of HCC. Using from one to four fibers on the physicians’ preference and experience. However, when all the
basis of tumor size, the reported complete response rates three “hot” ablation techniques are available in a single center,
range from 82% to 97%. [44-46] Mortality rate is < 1%, and major which thermal treatment should be preferred?
complication rate ranges from 0.1% to 3.5%. [47]
Each thermal modality presents peculiar technical
Advantages of LTA characteristics, advantages, and limitations. Likewise,
The main advantage of LTA is its feasibility, as LTA utilizes patients can have some contraindications to some ablation
very fine needles to insert the fibers into the lesion. Such a technique (for instance, the presence of a pacemaker is a
characteristic makes LTA particularly safe for the treatment of relative contraindication to RFA), and tumors can differ in
nodules with difficult location. Furthermore, the possibility number, size, and location. It follows that, in our opinion,
to use from one to four fibers allows to achieve ablation the choice should be based on the characteristics of the
areas different in size, enabling to treat lesions different in patient, tumor, and ablation techniques. For this purpose,
size or multiple small lesions in the same session, sparing we suggest the algorithm adopted in our Section of
the normal parenchyma as far as possible. In our experience, Interventional Ultrasound, aimed at tailoring the thermal
LTA is the cheapest ablation technique when up to three treatment on the single patient to achieve the best
fibers are used, and it is cheaper than MWA when four outcome [Figures 1 and 2].
fibers are used.
In short, a single nodule 2 cm or smaller in size can efficaciously
Limits of LTA be ablated using all the thermal modalities. Both RFA and LTA
The correct placement of the fibers can result technically are cheaper than MWA and should be preferred unless the

54 Hepatoma Research | Volume 1 | Issue 2 | July 15, 2015