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Della Corte et al. Hepatoma Res 2022;8:5 https://dx.doi.org/10.20517/2394-5079.2021.103 Page 7 of 15

characterized by abundant fibrous stroma, show higher rates of lymph node metastasis and poorer survival
[51]
outcomes than those with non-scirrhous type ICC .
[52]
A study by Pandey et al. assessing preoperative characteristics of ICC candidate to trans-arterial
chemoembolization demonstrated that overall survival (OS) was higher in patients with lower values of
baseline apparent diffusion coefficient, percentage of viable tumor volume > 90%, and viable tumor burden
> 6.6% independently from clinical confounders (age and sex). Data suggest that tumors characterized by
lower viable tumor burden, hence a greater degree of fibrosis and necrosis, are associated to a hostile tumor
microenvironment, where hypoxia, acidosis, and inadequate perfusion limit the efficacy of intra-arterial
drug delivery.

[53]
In peCC, a recent study by Yoo et al. on prognostic performance of preoperative MRI demonstrated that
imaging evidence of peritumoral fat stranding, common bile duct involvement, and Bismuth type III/IV
disease were independent predictors of residual disease after surgery, which was in turn associated to poorer
survival.

INTERVENTIONAL RADIOLOGY
Loco-regional treatments are gaining increasing interest in the field of ICC as technological advances
guarantee an effective disease control while maintaining the safety of a minimally invasive approach.
Knowledge of CC disease presentation as well as clinical characteristics of the patients are essential to select
the most appropriate interventional tool based on a personalized approach. Promising results from
combination of loco-regional treatments and systemic therapies of unresectable ICCs are also briefly
discussed in this article.

ABLATION
Ablation is the physical destruction of tumor cells via delivery of thermal energy through a percutaneous
needle placement. The low incidence of ICC compared to HCC, makes the availability of literature on the
efficacy of ablation scarce. First reported in 2002 by Slakey et al. for the treatment of non-resectable ICC,
[54]
ablation is now recognized by guidelines as a palliative option for non-resectable ICC measuring ≤ 3 cm
[16]
without evidence of extrahepatic disease . Kolarich et al. , through a population analysis of 4374 patients
[55]
undergoing non-surgical management of ICC, produced robust evidence in demonstrating that ablation
was associated with a statistically significant survival benefit over no local therapy only in stage I disease
(i.e., without extrahepatic disease).

Another setting where ablation has shown very interesting results is the management of post-surgical
intrahepatic recurrence of ICC. In a recent study by Xu et al. comparing repeated resection (n = 65) vs.
[56]
microwave ablation (n = 56) of recurrent ICC, with comparable tumor size among the two groups, ablation
had a similar efficacy in terms of overall survival and progression free survival with a much lower
complication rate.

Ablation can be performed under ultrasound or CT guidance as per local expertise, and several technical
options exist for reaching tumor tissue destruction. Among these, radiofrequency ablation is the most
extensively studied, with proven technique efficacy in tumors up to 5 cm . Microwave ablation have the
[57]
advantage of lower susceptibility to heat-sink effects, and with higher temperatures in a short time, it can
achieve larger ablation zones . However, these theoretical advantages have not effectively translated to an
[58]
improvement in prognosis , leaving the choice among radiofrequency ablation and microwave ablation to
[59]
local expertise and availability.