| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 All authors: Third Department of Internal Medicine, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
Received March 16, 2000;
accepted after revision April 3, 2001.
Address correspondence to K. Numata.
Abstract
 Top Abstract IntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
SUBJECTS AND METHODS. Forty-six patients with 65 HCC lesions were examined with contrast-enhanced sonography with direct injection of CO2 into the proper hepatic artery during arteriography. We performed percutaneous ethanol injection guided by CO2-enhanced sonography for the treatment of hypervascular HCC lesions that could not be treated with conventional percutaneous ethanol injection or with transcatheter arterial embolization.
RESULTS. CO2-enhanced sonography detected five additional small HCC lesions before treatment (p<0.05) and 14 new lesions during follow-up (p<0.01), than conventional sonography detected. CO2-enhanced sonography showed positive enhancement of residual lesions after initial treatment (n = 3) and incomplete local treatment (n = 5) that were not detected on conventional sonography. These 27 lesions were successfully treated with percutaneous ethanol injection using a mixture of iodized oil and ethanol and guided by CO2-enhanced sonography.
CONCLUSION. CO2-enhanced sonography is a sensitive method for detecting residual viable lesions and small new HCC lesions that cannot be detected with conventional sonography. Percutaneous ethanol injection guided by CO2-enhanced sonography can treat hypervascular HCC lesions that cannot be treated with conventional percutaneous ethanol injection or transcatheter arterial embolization.
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
CO2-enhanced sonography is a sensitive means of detecting small HCC lesions [4,5,6,7,8]. Kudo et al. [5] reported that the detection rate of tumor hypervascularity on CO2-enhanced sonography (86%) showed that it was more sensitive than digital subtraction arteriography (70%) and CT with iodized oil (82%). Imari et al. [6] reported that CO2-enhanced sonography is useful for the detection of hypervascular HCC and the treatment by percutaneous ethanol injection of lesions not detected using conventional sonography. After direct intraarterial injection of CO2, enhancement of the tumor lasts approximately 10-60 min. This enhancement provides sufficient time to perform percutaneous ethanol injection with a mixture of iodized oil and ethanol, a maneuver that enables detection of the HCC lesions on conventional sonography [6].
In this study, we evaluated the usefulness of CO2-enhanced sonography and percutaneous ethanol injection under CO2-enhanced sonography for the detection and treatment of the viable portion and of small lesions that are not detected with conventional sonography in patients who underwent combined transcatheter arterial embolization and percutaneous ethanol injection, or percutaneous ethanol injection therapy alone.
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
The study included 34 men and 12 women who were 42-79 years old (mean, 64 years). All lesions were the nodular type by gross anatomic classification. A total of 46 patients had 65 HCC lesions; 29 patients had a solitary tumor, 15 patients had two lesions, and two patients had three lesions. HCC was diagnosed by microscopic examination of specimens obtained at biopsy or autopsy. The size of the hepatic lesions was assessed by CO2-enhanced sonography or CT. The mean maximum diameter (±SD) of the HCC lesions was 2.7 ± 1.8 cm. All patients had cirrhosis, and the diagnosis was based on histologic or clinical examinations or both. The pathogenesis of the cirrhosis was alcohol in two patients; hepatitis B in five; hepatitis C in 35; hepatitis B and C in one; and non-B, non-C hepatitis in three. According to Child's classification [9], 30 patients had Child's class A cirrhosis, 15 had class B, and one had class C. Informed consent was obtained from all patients and their relatives.
Preprocedural Imaging Workup and Findings
The preprocedural diagnostic imaging workup of all patients included
conventional sonography, unenhanced and contrast-enhanced CT, arteriography,
and CO2-enhanced sonography.
CT was performed after a bolus administration of 100 mL of iohexol contrast material (Omnipaque; Sanofi Winthrop Pharmaceuticals, New York, NY). Selective hepatic arteriography and superior mesenteric arteriography were performed in all patients. If the HCC lesions were supplied by extrahepatic arteries, microcatheters were selectively introduced into the arteries. In the sinusoidal phase, the presence or absence of tumor staining of HCC lesions was evaluated using digital subtraction arteriography [10]. When the maximum diameter of the HCC lesion was less than 2 cm, CT during arterial portography and CT hepatic arteriography were performed. Findings of CT and arteriography were evaluated subjectively by two observers who were unaware of the findings of CO2-enhanced sonography.
Using a real-time convex scanner or linear array scanner with 3.5-MHz probes (SSD 650 or 650CL; Aloka, Tokyo, Japan), we performed CO2-enhanced sonography during each arteriography study in all patients to detect hypervascular lesions [5, 6, 8]. A total of 5-10 mL of CO2 was directly injected into the proper hepatic artery [6]. This method of CO2-enhanced sonography provides longer nodular enhancement than the microbubble injection method [11]. Whenever a hepatic artery showed severe stenosis or occlusion because of repeated transcatheter arterial embolization, the CO2 was injected into the extrahepatic feeding artery of the HCC lesion (inferior phrenic artery, gastric artery, renal artery, and so on).
Study Design
Figure 1 shows our study
design. Combined transcatheter arterial embolization and conventional
percutaneous ethanol injection treatment or percutaneous ethanol injection
alone was performed as the initial treatment of HCC lesions detected on
conventional sonography. The criteria for entry into the group receiving
combined transcatheter arterial embolization and percutaneous ethanol
injection therapy were met if the patient had three or fewer hypervascular
lesions; the largest dimension of the largest tumor exceeded 2 cm; no evidence
existed of advanced cirrhosis (serum bilirubin values of 
2.0 mg/dL and
indocyanine green test 40%); and no evidence existed of portal thrombosis,
extrahepatic metastasis, or ascites. The criteria for entry into the group
receiving conventional percutaneous ethanol injection therapy alone were met
if the patient had three or fewer lesions; the largest dimension of the
largest tumor did not exceed 2 cm; and no evidence was seen of portal
thrombosis, extrahepatic metastasis, or ascites.
|
The histologic diagnosis of small lesions detected on CO2-enhanced sonography and not on conventional sonography was made by 21-gauge fine-needle aspiration biopsy (Sonopsy; Hakko, Tokyo, Japan) under CO2-enhanced sonography. We performed percutaneous ethanol injection guided by CO2-enhanced sonography only after this biopsy. The criteria for entry to the group having percutaneous ethanol injection under guidance with CO2-enhanced sonography were met if the patient had a hypervascular HCC lesion on CO2-enhanced sonography and had poor liver function caused by advanced cirrhosis (total bilirubin >2.0 mg/dL or indocyanine green test >40%), or if the patient had a hypovascular lesion or faint tumor stain on digital subtraction arteriography, or if transcatheter arterial embolization was difficult because of stenosis or occlusion of the hepatic artery as a result of repeated transcatheter arterial embolization.
In HCC lesions that were diagnosed as hypervascular, conventional sonography, contrast-enhanced CT, arteriography, and CO2-enhanced sonography were also performed to detect residual tumor 1 or 2 weeks after initial treatment. If we detected positive enhancement in a lesion (the residual portion of tumor) on CO2-enhanced sonography, additional percutaneous ethanol injection guided by CO2-enhanced sonography was performed.
During the long-term follow-up, conventional sonography and contrast-enhanced CT were performed every 3 months after treatment to detect incomplete local treatment and new lesions. Arteriography and CO2-enhanced sonography were also performed every 6 months after treatment to detect incomplete treatment and new lesions. Whenever viable portions of treated lesions (incomplete treatment) and new lesions not detected on conventional sonography were detected on CO2-enhanced sonography, we performed percutaneous ethanol injection guided by CO2-enhanced sonography.
Therapeutic Techniques
Combined transcatheter arterial embolization and percutaneous ethanol
injection.—Combined transcatheter arterial embolization and
percutaneous ethanol injection were performed as described previously
[12,13,14].
We performed transcatheter arterial embolization by selectively introducing a
microcatheter into the right or left hepatic artery or a segmental branch of
the hepatic artery and injecting a mixture of an iodized oil (Lipiodol; Andre
Guerbet, Aulnay-sous-Bois, France) and styrene maleic acid neocarzinostatin
(1.0-6.0 mg per patient; SMANCS; Yamanouchi Pharmaceutical, Tokyo, Japan),
followed by a gelatin sponge (1 x 1 x 2 mm) (Gelfoam; Upjohn,
Kalamazoo, MI). SMANCS iodized oil was prepared by suspending 1 mg of SMANCS
in 1 mL of iodized oil. SMANCS in iodized oil exerts a more favorable focal
therapeutic effect in the initial treatment of HCC than epirubicin in iodized
oil [15].
Two weeks later, the therapeutic effect of transcatheter arterial embolization was assessed using CT. Then percutaneous ethanol injection of all lesions was performed, regardless of whether residual viable HCC was present on contrast-enhanced CT, because the rate of residual viable lesions has been shown to be high after transcatheter arterial embolization alone [12, 13, 16]. We used a real-time convex scanner or a linear-array scanner with 3.5-MHz probes and a lateral attachable apparatus for needle guidance (SSD 650 or 650CL). First, using sonographic guidance, we ascertained that a 15- or 20-cm long, 21-gauge puncture needle with a closed conical tip and three terminal side holes (PEIT needle; Hakko, Tokyo, Japan) was positioned correctly in the lesion; then a relatively large volume (1.2-75 mL) of 99.5% absolute ethyl alcohol was slowly injected. Care was taken to inject into the deepest portions of the lesion first, followed by the more central and superficial portions, to prevent any superficial spread of ethanol from masking the view for subsequent injections. In one treatment session, we commonly used one or more PEIT needles, and ethanol was injected into the tumor at one or more locations until the lesion was completely filled. The treatment was performed two times per week. Six or more treatment sessions were usually performed in one treatment series, and the total amount of ethanol administration varied according to the lesion volume, the texture of the tumor parenchyma, patient compliance, and the distribution of the ethanol.
Percutaneous ethanol injection guided by CO2-enhanced sonography.—We also used a real-time convex scanner or linear-array scanner with 3.5-MHz probes and a lateral attachable apparatus for needle guidance. Under guidance with CO2-enhanced sonography, we confirmed that the PEIT needle was positioned correctly in the lesion, and then we injected 0.4-6.0 mL of an iodized oil-ethanol mixture (1:1 or 1:2). If the HCC lesion was equal to or smaller than 2 cm in diameter, iodized oil-ethanol was prepared by suspending 1 mL of iodized oil in 1 mL of ethanol. In cases of lesions greater than 2 cm in diameter, iodized oil-ethanol was mixed with 2 mL of iodized oil in 1 mL of ethanol. After the lesions were marked in this manner, they usually became slightly hyperechoic rather than isoechoic and could then be treated with conventional percutaneous ethanol injection (Fig. 2A,2B,2C,2D,2E,2F). Additional percutaneous ethanol injection was performed two times per week. Four or more treatment sessions were usually performed in one treatment series. The total volume of ethanol injected during additional conventional percutaneous ethanol injection therapy ranged from 3.3 to 125 mL (mean ± SD, 15.7 ± 24.1 mL), and the volume used each session ranged from 0.7 to 50 mL (3.8 ± 7.1 mL).
|
|
|
|
|
|
Diagnosis of Therapeutic Effect
We evaluated the effect of percutaneous ethanol injection using
contrast-enhanced CT because this method can correctly depict percutaneous
ethanol injection-induced necrosis in HCC and is reliable for evaluating the
therapeutic effect of the injection
[17]. After percutaneous
ethanol injection, a necrotic area of HCC and the surrounding liver parenchyma
was characterized as hypoattenuating at both early and late phases of
contrast-enhanced CT. After percutaneous ethanol injection, if the necrotic
area depicted on contrast-enhanced CT was larger than the viable area depicted
by contrast-enhanced CT before treatment, the therapy was considered
technically successful (Fig.
3A,3B,3C,3D).
|
|
|
|
We also evaluated the effect of therapy using CO2-enhanced sonography for hypervascular lesions at the time of initial treatment, and for new lesions during the follow-up period that evaluation of residual tumor was difficult with contrast-enhanced CT because of the presence of iodized oil (Fig. 2A,2B,2C,2D,2E,2F). If a lesion that was positively enhanced on CO2-enhanced sonography before treatment exhibited negative enhancement after treatment, adequate tumoral necrosis or tumor destruction was inferred by combined transcatheter arterial embolization and percutaneous ethanol injection or by percutaneous ethanol injection therapy alone (Fig. 2A,2B,2C,2D,2E,2F).
Statistical Analysis
Data are expressed as the mean ± SD. Data were statistically
analyzed by one-way analysis of variance. Differences within groups were
evaluated using the paired t test. Relationships between categoric
variables were analyzed using the chi-square test. A p value of less
than 0.05 was considered statistically significant. Survival data were
evaluated using the Kaplan-Meier method
[18]. Survival was measured
from the date of the first treatment until death.
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
|
Therapeutic Usefulness of CO2-Enhanced Sonography During
Initial Therapy
Forty patients had 55 hypervascular lesions detected on conventional
sonography, and they were treated with transcatheter arterial embolization.
After this therapy, 21 (38%) of the 55 lesions showed residual early
enhancement on contrast-enhanced CT, and all 55 lesions were treated with
additional percutaneous ethanol injection. Two (5%) of the 40 patients each
had an additional small HCC lesion that was not identified on conventional
sonography but that showed positive enhancement on CO2-enhanced
sonography. These two lesions showed a faint tumor stain on digital
subtraction arteriography, and they were visualized as high-attenuation areas
on CT during arteriography. Both were treated by percutaneous ethanol
injection guided by CO2-enhanced sonography
(Table 2 and Fig.
3A,3B,3C,3D).
|
Five patients with five hypovascular HCC lesions received conventional percutaneous ethanol injection alone, and adequate tumoral necrosis or tumor destruction was shown on contrast-enhanced CT. One (20%) of the five patients had two additional small HCC lesions that were not identified on conventional sonography but that showed positive enhancement on CO2-enhanced sonography. On digital subtraction arteriography, however, these lesions appeared to be hypovascular. These lesions were visualized as high-attenuation areas on CT during arteriography and were treated by percutaneous ethanol injection guided by CO2-enhanced sonography (Table 2).
The remaining one patient had one small hypervascular HCC lesion detected on contrast-enhanced CT but not identified on conventional sonography that showed positive enhancement on CO2-enhanced sonography. This patient was found to have a hypervascular lesion on digital subtraction arteriography, but he had poor liver function because of advanced cirrhosis. The lesion was visualized as a high-attenuation area on CT during arteriography and was treated by percutaneous ethanol injection guided by CO2-enhanced sonography (Table 2).
Therefore, the initial treatment was a combination therapy consisting of transcatheter arterial embolization and percutaneous ethanol injection in 55 (85%) of the 65 lesions, percutaneous ethanol injection guided by CO2-enhanced sonography in five other lesions (7.5%), and conventional percutaneous ethanol injection alone in the remaining five lesions (7.5%).
Diagnostic and Therapeutic Usefulness of CO2-Enhanced
Sonography at the First Examination After the Completion of Therapy
After their initial treatment, 42 patients who had 60 hypervascular HCC
lesions were examined again with contrast-enhanced CT, digital subtraction
arteriography, and CO2-enhanced sonography. Fifty-six (93%) of the
60 lesions showed adequate tumor necrosis or destruction on these modalities.
Three (7%) of the 42 patients had four residual lesions. Three of four lesions
were detected on these three modalities; however, the remaining one lesion (a
satellite nodule) was not detected on contrast-enhanced CT. Two patients with
three lesions received percutaneous ethanol injection guided by
CO2-enhanced sonography to residual tumors (n = 2) and a
satellite nodule (n = 1) that were not detected on conventional
sonography (Table 2 and Fig.
4A,4B,4C,4D,4E).
The remaining one patient with one lesion received transcatheter arterial
embolization alone. The mean maximum diameter of these three primary HCC
lesions was 8.3 ± 3.0 cm.
|
|
|
|
|
Diagnostic Usefulness of CO2-Enhanced Sonography for
Long-Term Follow-Up
Table 3 shows the rate of
detection of incomplete local treatment or new HCC lesions that were detected
on conventional sonography, contrast-enhanced CT, digital subtraction
arteriography, and CO2-enhanced sonography. CO2-enhanced
sonography detected 14 more lesions (40%) of the 35 total lesions than
conventional sonography alone. CO2-enhanced sonography was a more
sensitive means of detecting incomplete local treatment or new HCC lesions
than conventional sonography or digital subtraction arteriography (p
< 0.01 and p < 0.05, respectively).
|
We observed all 46 patients for at least 6 months. The mean follow-up period of these patients was 20 months (range, 6-40 months). A total of 45 and 41 patients were observed for a follow-up period of 1 and 3 years, respectively, and the 1- and 3-year survival rates of all patients were calculated to be 97% and 77%, respectively. Of the 46 patients, the four patients with five hypovascular lesions treated by conventional percutaneous ethanol injection alone and the four patients with five lesions treated by percutaneous ethanol injection guided by CO2-enhanced sonography had no recurrences during the follow-up period. However, incomplete local treatment or new lesions were seen in 24 patients (52%) with 35 lesions recognized with early enhancement on contrast-enhanced CT, tumor staining on digital subtraction arteriography, or positive enhancement on CO2-enhanced sonography during the follow-up period. Incomplete local treatment was observed in nine patients (19.6%) during a 4- to 29-month period (including three patients with incomplete local treatment and new lesions), whereas new lesions alone were seen in 15 patients (32.6%) with 23 lesions during a 4- to 34-month period.
The mean maximum tumor diameter in patients with incomplete local treatment was significantly greater than that in patients with new lesions (p < 0.01). The maximum diameter of the nine lesions with progressive tumor growth (incomplete local treatment) ranged from 1.5 to 10 cm (mean±SD, 3.3 ± 2.4 cm), and the maximum diameter of the 26 new lesions ranged from 0.8 to 3 cm (mean, 1.7 ± 0.9 cm). The period in which this progressive tumor growth was recognized after these therapies ranged from 4 to 34 months (mean, 14.8 ± 10.5 months).
Therapeutic Usefulness of CO2-Enhanced Sonography and
Marking of the Lesions for Retreatment
Of the 24 patients with incomplete local treatment or new lesions, six
patients (25%) with six lesions received combined transcatheter arterial
embolization and percutaneous ethanol injection therapy, four patients (17%)
with five lesions received percutaneous ethanol injection alone, and two
patients (8%) with five lesions received transcatheter arterial embolization
alone. The remaining 12 patients (50%) with 19 lesions received percutaneous
ethanol injection guided by CO2-enhanced sonography
(Table 2).
CO2-enhanced sonography detected more new lesions than any of the
other three modalities. All 14 new lesions showed positive enhancement on
CO2-enhanced sonography and were not detected on conventional
sonography. Therefore, these new lesions could not be treated with
percutaneous ethanol injection guided by conventional sonography. Almost all
these new lesions were located in the deep portion or the surface of the
liver, or near the heart or the diaphragm. After marking with an iodized
oil-ethanol mixture, these 19 lesions could be treated with additional
conventional percutaneous ethanol injection. Contrast-enhanced CT revealed
adequate tumor necrosis or tumor destruction in all cases.
Outcome for Patients Who Were Treated with Percutaneous Ethanol
Injection Guided by CO2-Enhanced Sonography
We observed 18 patients with 27 lesions treated with percutaneous ethanol
injection guided by CO2-enhanced sonography. The follow-up period
of these patients was 7.8 ± 2.1 months. After percutaneous ethanol
injection guided by contrast-enhanced sonography, four of 18 patients had new
lesions. One patient died of sepsis resulting from pneumonia. Two of the three
patients with large HCC lesions who had residual tumors and who received
additional treatment had recurrences with new lesions (Fig.
4A,4B,4C,4D,4E).
One patient died as a result of the tumor, and another died of liver
failure.
Complications
No serious complications occurred during or after percutaneous ethanol
injection guided by CO2-enhanced sonography.
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
Conventional sonography can identify large or treated HCC lesions but cannot clearly distinguish viable from nonviable portions of these lesions. It is almost impossible to evaluate the necrotic area produced with percutaneous ethanol injection using conventional sonography because of the similar appearance of necrosis and viable tumor tissue [19]. It is also difficult to detect small HCC lesions located in the deep portion or the surface of the liver, or those located near the heart or the diaphragm. However, CO2-enhanced sonography is a more sensitive technique for detecting small hypervascular HCC lesions and the viable portion of treated HCC lesions than conventional sonography, CT, and digital subtraction arteriography [5, 8, 19]. In this study, we have shown that CO2-enhanced sonography can detect more small HCC lesions before initial treatment than conventional sonography, contrast-enhanced CT, or digital subtraction arteriography. This method can also detect both the viable portion in lesions treated with percutaneous ethanol injection and new HCC lesions not detected with conventional sonography. CO2-enhanced sonography is especially useful for detecting small hypervascular HCC lesions that cannot be seen on conventional sonography. This easy and safe method clearly increased the detection rate of small HCC lesions. CO2-enhanced sonography will likely be beneficial in patients with hypervascular HCC lesions on contrast-enhanced CT to detect other small hypervascular HCC lesions not detected on conventional sonography. However, in our study, only two small additional hypervascular HCC lesions not detected on conventional sonography were detected on CO2-enhanced sonography in one of the five patients with hypovascular HCC lesions on contrast-enhanced CT (Tables 1,2,3). We do not think that angiographic examinations, including CO2-enhanced sonography, necessarily need to be performed in HCC patients who have hypovascular lesions on contrast-enhanced CT.
Chen et al. [20] reported that CO2-enhanced sonography is a highly reliable method for detecting the viable part of treated HCC lesions; when CO2-enhanced sonography shows enhancement, further therapy is necessary. In our study, three large HCC lesions had residual lesions after transcatheter arterial embolization and percutaneous ethanol injection therapy. Therefore, CO2-enhanced sonography may be an important examination in patients with large HCC lesions before and after treatment as part of a strict follow-up.
Transcatheter arterial embolization has been widely used in the treatment of patients with nonresectable HCC [1, 2]. However, the efficacy of transcatheter arterial embolization mainly depends on the vascularity of HCC lesions [8, 21,22,23]. In cases of hypovascular HCC on digital subtraction arteriography, transcatheter arterial embolization is not effective. The effectiveness of transcatheter arterial embolization is also limited if small HCC lesions have extracapsular invasion or are formed by several small contiguous tumor nodules [24]. Even after successful transcatheter arterial embolization, the tumor frequently recurs [25, 26]. Therefore, additional treatment is needed to obtain adequate tumor necrosis of even small HCC lesions.
Percutaneous ethanol injection has been used as a potentially curative treatment that is performed mainly in patients with poor liver function, three or fewer lesions, and tumors equal to or less than 3 cm in diameter [27]. Survival and incomplete local treatment or new lesion rates of patients treated with percutaneous ethanol injection are similar to those who undergo surgical resection [27, 28]. Therefore, we performed percutaneous ethanol injection guided by CO2-enhanced sonography for treatment of hypervascular HCC lesions on CO2-enhanced sonography that could not be treated with conventional percutaneous ethanol injection or transcatheter arterial embolization. After these lesions were marked with an iodized oil-ethanol mixture, they could all be visualized on conventional sonography and could be treated with additional conventional percutaneous ethanol injection.
In this study, we directly injected 5-10 mL of CO2 into the proper hepatic artery [6]. This method is simple and leaves sufficient time for percutaneous ethanol injection with a mixture of iodized oil and ethanol. In this method of CO2-enhanced sonography, enhancement of the tumor continued for 15-60 min (mean, 19.6 ± 13.5 min), which was longer than that in the microbubble injection method (4.0 ± 2.3 min) [10].
Some earlier studies have also evaluated the viable portion of HCC using color Doppler sonography, power Doppler sonography, and contrast-enhanced color Doppler sonography after transcatheter arterial embolization or percutaneous ethanol injection treatments [29,30,31,32]. Contrast-enhanced color and power Doppler sonography with IV contrast material has recently been reported to be useful in evaluating the therapeutic effect of radiofrequency ablation therapy for malignant liver tumors [33, 34]. However, it is difficult to evaluate the tumor vascularity of HCC lesions located deep in the liver or near the heart using these methods. In our follow-up period, the recurrence of small new HCC lesions not detected on conventional sonography increased. Even using contrast-enhanced Doppler sonography with IV sonographic contrast agents such as Levovist (Schering, Berlin, Germany), it is difficult to detect these new lesions and to evaluate the viability of the lesions not detected with conventional sonography. Therefore, percutaneous ethanol injection guided by CO2-enhanced sonography is especially useful for treating lesions that cannot be detected with conventional sonography. Other thermal therapies, including radiofrequency ablation (and microwave and laser) therapy guided by CO2-enhanced sonography, may also be useful for the treatment of lesions that cannot be detected on conventional sonography if the lesion is suitable for treatment by other thermal therapies.
Solbiati et al. [33] used contrast-enhanced CT as the gold standard to evaluate residual tumor after radiofrequency ablation therapy, and our results suggest that CO2-enhanced sonography may be more sensitive than contrast-enhanced CT. Thus, the use of their imaging gold standard may have been less than ideal. In any event, the lack of a pathologic gold standard in both their study and ours may limit comparison of the findings between studies. Nevertheless, any technique such as CO2-enhanced sonography that detects additional lesions should prove useful in clinical practice.
The introduction of CO2-enhanced sonography was expected to reduce incomplete local treatment or new lesions during the follow-up period and to improve the survival rate of patients. An earlier study on the same subject, in which transcatheter arterial embolization and percutaneous ethanol injection were used, yielded 1-, 3-, and 5-year survival rates for the 83 patients of 100%, 68%, and 35%, respectively; but the rates of incomplete local treatment and new lesions remained high (77%) [14]. the incomplete local treatment rate was 24% during the 3-37 months after treatment, and new lesions appeared in 53% of patients during a 3- to 62-month period after treatment [14]. In our study, the overall cumulative survival rates were 97% and 77% at 1 and 3 years, respectively. The percentage of lesions that required further therapy during the course of follow-up in our patient population was 52%. Specifically, the incomplete local treatment rate was 19.5% during a 4- to 29-month period after treatment, and new lesions appeared in 32.5% of patients during a 4- to 34-month period after treatment. Short-term survival rates and incomplete local treatment or new lesion rates may have improved since the introduction of CO2-enhanced sonography, but further studies are needed to clarify whether CO2-enhanced sonography improves long-term survival rates.
CO2-enhanced sonography is a sensitive method for detecting the residual viable portion of primary HCC lesions and for finding small new HCC lesions that could not be found with conventional sonography. Percutaneous ethanol injection guided by CO2-enhanced sonography could be an option for patients for whom transcatheter arterial embolization is contraindicated. Furthermore, this therapy can treat small hypervascular HCC lesions that cannot be treated with conventional percutaneous ethanol injection, and it may improve the survival rate of patients with HCC.
|
TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
|---|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  S. Nagaoka, S. Itano, H. Nagamatsu, J. Akiyoshi, J. Kurogi, N. Tajiri, M. Kajiwara, and M. Sata Temporary Indwelling Catheter System via the Left Brachial Artery: Evaluation in 83 Patients with Hepatic Tumors Am. J. Roentgenol., March 1, 2007; 188(3): 652 - 658. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Minami, M. Kudo, H. Chung, T. Kawasaki, Y. Yagyu, T. Shimono, and H. Shiozaki Contrast Harmonic Sonography-Guided Radiofrequency Ablation Therapy Versus B-Mode Sonography in Hepatocellular Carcinoma: Prospective Randomized Controlled Trial Am. J. Roentgenol., February 1, 2007; 188(2): 489 - 494. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Hirooka, H. Iuchi, T. Kumagi, S. Shigematsu, A. Hiraoka, T. Uehara, K. Kurose, N. Horiike, and M. Onji Virtual Sonographic Radiofrequency Ablation of Hepatocellular Carcinoma Visualized on CT but Not on Conventional Sonography. Am. J. Roentgenol., May 1, 2006; 186(5 Suppl): S255 - S260. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Minami, M. Kudo, T. Kawasaki, H. Chung, C. Ogawa, and H. Shiozaki Treatment of Hepatocellular Carcinoma with Percutaneous Radiofrequency Ablation: Usefulness of Contrast Harmonic Sonography for Lesions Poorly Defined with B-Mode Sonography Am. J. Roentgenol., July 1, 2004; 183(1): 153 - 156. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Minami, M. Kudo, T. Kawasaki, H. Chung, C. Ogawa, and H. Shiozaki Percutaneous Radiofrequency Ablation Guided by Contrast-Enhanced Harmonic Sonography with Artificial Pleural Effusion for Hepatocellular Carcinoma in the Hepatic Dome Am. J. Roentgenol., May 1, 2004; 182(5): 1224 - 1226. [Full Text] [PDF]
|
|
|
|
|
|
M. Kitamoto, M. Imagawa, H. Yamada, C. Watanabe, M. Sumioka, O. Satoh, M. Shimamoto, M. Kodama, S. Kimura, K. Kishimoto, et al. Radiofrequency Ablation in the Treatment of Small Hepatocellular Carcinomas: Comparison of the Radiofrequency Effect With and Without Chemoembolization Am. J. Roentgenol., October 1, 2003; 181(4): 997 - 1003. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Numata, T. Isozaki, Y. Ozawa, T. Sakaguchi, T. Kiba, T. Kubota, A. Ito, K. Sugimori, K. Shirato, M. Morimoto, et al. Percutaneous Ablation Therapy Guided by Contrast-Enhanced Sonography for Patients with Hepatocellular Carcinoma Am. J. Roentgenol., January 1, 2003; 180(1): 143 - 149. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
