Patients:
In this study,
72 patients with 86 HCCs of RFA high-risk group who underwent combined use of PEI and RFA in Dongsan medical center of Keimyung university between January 1,
2010,
and Aprial 31,
2013 were evaluated retrospectively with their medical records kept when they had visited our center and got the procedure.
The RFA high-risk group criteria were as follows: Tumors are located within 10mm away from liver vessels more than 3mm in diameter,
hepatic capsules or vital organs such as a gall bladder,
kidney,
diaphragm,
spleen,
or colon,
hardly treated with RFA alone.
And we excluded patients with extrahepatic metastasis at the time procedures performed.
Procedure techniques:
PEI followed by simultaneous RFA were performed.
One radiology specialist performed this procedure,
and decided patient's position considering accessibility to the lesion from skin.
Just before the procedure,
we confirmed the location of tumors by scanning a computed tomography(CT),
then we decided the angle and the depth of puncture by using geometrical relations between the target lesion shown on the CT scan and the skin puncture site.
To reduce pains of puncture,
we used 10ml of 2% lidocaine HCL as local anesthesia and injected fentanyl 1mL to patients suffering severe pains. Along the targeted puncture route,
we tried targeted punctures using 21 gauged or 22 gauged percutaneous ethanol injection needles with 3 or 6 holes on their lateral sides(Hakko,
Tokyo,
Japan).
We gradually inserted the needle forward in stages by a 2 to 3 cm,
then take a CT scan to check the direction and the tip of the needle,
and inserted again.
We located the tip of the needle inside the tumors of RFA high-risk group,
but into parts of tumors relatively nearby liver capsules,
vessels or vital organs. We injected 3-4 ml of ethanol each time until reaching the target amount of ethanol,
as much as possible up to 25 mL per each procedure,
and every time we injected ethanol,
took a CT scan to see if the ethanol diffused into tumors.
We ended up the procedure when all the tumor burden changed to hypoattenuation lesion,
considering that complete ablation of HCC.
After then,
we performed RFA as CT guided percutaneous procedure and used Cool-tip RF system.
We located the tip of Cool-tip RF system inside the tumors of RFA high-risk group,
but into parts of tumors relatively far from liver capsules,
vessels or vital organs.
And we maintained the temperature of the tip at 60℃ for 12 minutes.
If a tumor is more than 3 cm,
multiple overlapping ablationswere performedto cover the whole tumor plus a 5mm ablation margin around the tumor.
Patient characteristics: (see figure 1)
HCCs of high risk group included in this study were diagnosed based on typical findings by contrast enhanced abdomen CT scans,
MRI scans or α-fetoprotein tests.
The diagnosis also was made cytologically with liver biopsy.
The mean age of the patients was 65.6 years (range,
44–84 years).
Patients were male dominant,
52 male patients (72.2%) and 20 female ones(27.8%).
The causes of HCCs were as follows : 43 patients of hepatitis B virus (59.7%),
the most common cause in this study,
12 of hepatitis C virus(16.7%),
9 patients of alcohol(12.5%),
4 of coinfection of hepatitis B and C(5.5%),
and 4 of others(5.5%).
The mean concentration of a-FP of 86 HCCs on the high-risk group treated with the procedure was 541.3 ng/mL (1.0-27805.0 ng/mL).
Out of 86 cases,
72 cases(83.7%) were over 200 ng/mL and 14 case(16.3%) less than 200 ng/mL.
There were 73 Child-Pugh A patients(84.9%),
13 Child-Pugh B patients(15.1%) and no Child-Pugh C patients.
The mean tumor size was 2.4 cm,
consisted of 67 cases(77.9%) less than 3cm,
19 cases(22.1%) 3cm or larger than 3cm.
The distinct margin of tumor was defined as distinguish from liver parenchyme more than 50% of tumor margin at radiological imaging study.
The distinct margin of tumor was 61 case (70.9%),
indistinct margin of tumor was 25 case (29.1%).
At the time when we do procedure,
6 case was combined with portal vein tumor thrombosis (7.0%),
and 80 case had no portal vein tumor thrombosis (93.0%).
Causes of RFA high-risk group were as follows: 41 cases(47.7%) of HCCs abutting large vessels more than 3mm in diameter,
66 cases(76.7%) abutting liver capsules and 48 cases(55.8%) abutting vital organs and 63 cases(73.3%) with more than two factors.
In 12 cases(14.0%),
combination therapy were initial therapy for underlying HCC.
And 74 cases(86.0%) were initially treated by other therapy such as surgery,
TACE or other local therapy.
On the side of target HCC for this time procedure, 50 cases(58.1%) were initially treated by combination therapy and 36 cases(41.9%) were already treated by other therapy such as TACE or other local therapy.
Assessment of treatment efficacy:
We ran an enhanced CT scan on the first day and then a month after the procedure to evaluate the technical success rate and primary technical effectiveness.
And after that follow-up CT scans were performed every 3~6month to find out recurrences.
We judged the lesion as complete necrosis when low density ablated lesion included whole area of the tumor treated enough on the follow-up CT scans on the first day and then a month after the procedure.
And we judged the lesions as incomplete necrosis when it was enhanced around treatment area at an arterial phase and hypoattenuated mass remained at portal and venous phase.
Then if a new tumor was found contrast enhanced at arterial phase and hypoattenuated at portal and venous phases along the margin of local treatment area on the follow-up CT,
we judged it as a local recurrence.
Statistical analysis :
We used the program for statistical analysis that Window SPSS 18.0(SPSS Inc,
Chicago,
ILO,
USA),
and we calculated cumulative local recurrence - free survival rate by Kaplan-Meier method.
The time to recurrence after starting treatment was defined as detecting local recurrence at radiological image finding.
A univariate analysis of the survival curves were performed using the log-rank test.Differences with P < 0.05 were statistically significant.