International Journal of Modern Cancer Therapy (2000) Vol.3
|The Treatment of Irresectable Liver
Percutaneous Targeted Ar-He Cryoablation
|Senming Wang, Jiren Zhang, Qiuping Peng,
Yan Zhao, Guoqang Chen, Hongqing Wu
Oncology Center, Zhujiang Hospital, First Military Medical University,
Guangzhou 510282, China
ABSTRACT The aim of this investigation was to evaluate the results
and safety of percutaneous targeted Ar-He (argon-helium) cryoablation
in irresectable malignant Liver tumors. Between Oct 1999 and
Feb 2000, 30 patients with irresectable hepatocellular carcinoma
(13 patients) and irresectable metastases form colorectal cancer
(17 patients) were selected to be treated with CRYOcare surgical
system. Double freeze-thaw cycles were performed with 15-20
minutes freezing. Follow-up monitoring was performed at 1 week,
1 month and then every 3 months after cryoablation. There were
no intraoperative or postoperative complications. The first
CT study suggested complete destruction of all liver tumors
smaller than 3 cm, and no local recurrence within a follow-up
interval. The tumors with a diameter of more than 3cm were 90
percent destroyed. The serum levels of AFP or CEA decreased
within various extents and half of them returned to normal over
a period of 1 month to 3 months. The postoperative CD3+, CD4+,
CD8+ T lymphocytic subsets, CD3--/CD56+/CD16+ NK cell of the
peripheral blood had been found to be increased significantly
(p<0`05). We concluded that Percutaneous targeted Ar-He cryoablation
in treatment of the patients with irresectable liver tumors
is an advantageous, effective and safe cryotherapy. The CRYOcare
surgical system is the powerful and easy to be useful cryosurgery
KEYWORDS cryotherapy, Percutaneous cryoablation, liver tumors.
Cryoablation of liver tumors is more used in oncological clinical
when hepatic resection cannot be performed, or clearance is
restricted by anatomical limitation. Advances in the technology
of cryomachines and the experience gained in the open cryoablation
of liver tumors have allowed todevelop a new percutaneous targeted
Ar-He (argon-helium) cryoablation for treatment of the patients
with irresectable liver tumor. The aim of this investigation
was to evaluate the results and safety of this new cryotherapy.
PATIENTS AND METHODS
Between Oct 1999 and Feb 2000, 30 patients with irresectable
malignancy liver tumors were selected for percutaneous targeted
Ar-He cryoablation, including 13 patients with hepatocellular
carcinoma (HCC) and 17 patients with colorectal liver metastases.
Only patients with liver tumors that could be visualized clearly
by ultrasonography were included .The median age of these patients
was 55 (range 30-65) years and 18 were men .The mean diameter
of liver tumors was 4.7 (range 2-10) cm.
Cryoablation was performed with CRYOcare surgical system (Endocare
corporation, USA). The CRYOcare system provided various ultrasound-guided
probes(2, 3, 5, 8mm diameter) and continuous temperature monitoring
of targeted tissue. Ultrasonography (US) or computed tomograpy(CT)
were used to target the lesion, and to monitor iceball during
the percutaneous targeted Ar-He cryoablation.
Under local anesthesia, the cryoprobe was inserted into tumor
with US or CT guidance. Liquid argon was delivered to the tip
of probe and the temperature of the targeted lesion reached
-150℃ within 10 second. The formation of an iceball had to exceed
the tumor margin by 1 cm, achieving a temperature of -40℃ at
the tumor edge. The temperature in target tissue was increased
to be 20-40℃ by delivering liquid helium to frozen zone for
5 minutes. Then the second freeze-thaw cycle was performed.
Patients were kept in hospital for at least 2 days after percutaneous
targeted Ar-He (argon-helium) cryoablation. Follow-up monitoring
consisted of CT, US and determination of AFP or CEA at 1 week,
1 month and then every 3 months after cryoablation, also the
CD3+, CD4+, CD8+ T lymphocytic subsets, CD3--/CD56+/CD16+ NK
cell of the peripheral blood were evaluated with the flow cytometry.
The probes of 2, 3, 5 mm produced iceballs of 2.5×4.5, 3.5×6,
6×7 cm respectively after 15-20 minutes freezing. Lesion was
surrounded by the low-density iceball (Fig 1). The contrast
enhanced CT demonstrated there was low-density lesion in the
central portion of the cryolesion at 1 week later (Fig 2). The
first CT study suggusted complete destruction of all liver tumors
smaller than 3cm (n=11) and no local recurrence within a follow-up
interval (range 1-3 months). The tumors with diameter of more
than 3cm (n=19) were 90 percent destroyed. Pathologic specimen
1-week post freezes showed necrosis of the frozen tumor tissue(Fig
The postoperative CD3+, CD4+, CD8+ T lymphocytic subsets, CD3--/CD56+/CD16+
NK cell of the peripheral blood increased significantly (p<0`05).
There were no intraoperative or postoperative complication,
such as cracking of the lesions, bile fistula, bleeding. All
patients recovered quickly. The mean hospital stay after the
procedure was 2 (range 1-4) days.
Table. The level of T lymphocyte and NK cell (x±s,%)
|Postoperative (1 week)
Cryoablation is now a widely accepted modality for dealing with
irresectable liver tumors, in particular
for patients with lesion in multiple lobes, tumors in locations
that are difficult to resect and for patients with limited hepatic
functional reserve . Cryoablation may increase the number
of patients with irresectable liver tumors. Rather than an alterative
to resection, cryoablation is to be regarded as a complement
to hepatectomy and as an additional means to achieve tumor eradication
. Cryoablation may achieve complete tumor destruction by
very low temperature and increase immune function after procedure.
Cryosurgery is mainly employed via laparotomy. Some study suggests
that percutaneous cryoablation is an effective alterative to
open cryoablation [3,4]. In the initial experience with percutaneous
cryoablation, suitable lesions were selected, namely solitary
tumors that were readily accessible with a percutaneous probe
and easily visible on ultrasonography before and during the
In our study, Endocare`s CRYOcare surgical system, a new argon-based
CRYOcare system can create an iceball faster with steeper internal
temperature gradients than liquid nitrogen-based cryomachines
. Furthermore, helium gas rapidly can increase the temperature
of frozen tissue, which led to further tumor destruction. Liver
tumors smaller than 3 cm were completely destroyed and others
were 90 percent destroyed. The level of T lymphocyte and NK
cell of the peripheral blood increased after the procedure,
which suggests immune function of the patients were enhanced.
With ultrasound-guided probes and continuous temperature monitoring
of targeted tissue, the CRYOcare system provides the highest
levels of precision and control to avoid damage to surrounding
tissue. There were no introperative or postoperative complication.
The CRYOcare system is small and easy to use. The technical
feasibility of the procedure (i.e. reaching the lesion and monitoring
the iceball by US) was no more difficult than with open cryoablation.
Acknowledging that the number of patients was small and the
length of follow-up was short, the series suggests that percutaneous
targeted Ar-He cryoablation in irresectable liver tumors is
an advantageous, effective and safe alternative to open cryoablation
and the CRYOcare surgical system is the powerful and easy to
use cryosurgery system available.
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