Hyunchul Rhim - Academia.edu (original) (raw)

Papers by Hyunchul Rhim

Korean Journal of Radiology, 2009

Objective The objective of this study was to evaluate the safety and therapeutic efficacy of perc... more Objective The objective of this study was to evaluate the safety and therapeutic efficacy of percutaneous radiofrequency (RF) ablation for the treatment of hepatocellular carcinomas (HCCs) adjacent to the gallbladder with the use of internally cooled electrodes. Materials and Methods We retrospectively assessed 45 patients with 46 HCCs (mean size, 2.2 cm) adjacent to the gallbladder (≤1.0 cm) treated with RF ablation using an internally cooled electrode system. An electrode was inserted into the tumor either parallel (n = 38) or perpendicular (n = 8) to the gallbladder wall. The safety and therapeutic efficacy of the procedures were assessed with clinical and imaging follow-up examinations. Follow-up with the use of CT ranged from four to 45 months (mean, 19 months). The association between variables (electrode direction, electrode type, tumor size, tumor location, lobar location) and the presence of a residual tumor or local tumor progression was also analyzed. Results There were n...

Korean Journal of Radiology, 2020

Objective: To evaluate the effect of perfluorobutane microbubbles (Sonazoid®, GE Healthcare) on s... more Objective: To evaluate the effect of perfluorobutane microbubbles (Sonazoid®, GE Healthcare) on steam popping during radiofrequency (RF) ablation for treating hepatocellular carcinoma (HCC), and to assess whether popping affects treatment outcomes. Materials and Methods: The institutional review board approved this retrospective study, which included 90 consecutive patients with single HCC, who received percutaneous RF ablation as the first-line treatment. The patients were divided into two groups, based on the presence or absence of the popping phenomenon, which was defined as an audible sound with a simultaneous sudden explosion within the ablation zone as detected via ultrasonography during the procedure. The factors contributing to the popping phenomenon were identified using multivariable logistic regression analysis. Local tumor progression (LTP) and disease-free survival (DFS) were assessed using the Kaplan-Meier method with the log-rank test for performing comparisons between the two groups. Results: The overall incidence of the popping phenomenon was 25.8% (24/93). Sonazoid® was used in 1 patient (4.2%) in the popping group (n = 24), while it was used in 15 patients (21.7%) in the non-popping group (n = 69). Multivariable analysis revealed that the use of Sonazoid® was the only significant factor for absence of the popping phenomenon (odds ratio = 0.10, p = 0.048). There were no significant differences in cumulative LTP and DFS between the two groups (p = 0.479 and p = 0.424, respectively). Conclusion: The use of Sonazoid® has a suppressive effect on the popping phenomenon during RF ablation in patients with HCC. However, the presence of the popping phenomenon may not affect clinical outcomes.

Journal of applied clinical medical physics, Sep 8, 2016

The purpose of this study was to examine the correlation of quantitative dynamic contrast-enhance... more The purpose of this study was to examine the correlation of quantitative dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) with microvessel density (MVD) in necrotic, partial necrotic, and viable tumors using a rabbit VX2 liver tumor model. Nine rabbits were used for this study. The complete necrotic area (CNA), partial necrotic area (PNA), and viable tumor area (VTA) of liver tumors were experimentally induced by radiofrequency ablation (RFA). DCE-MRI data were processed based on the extended Kety model to estimate Ktrans,ve and vp parameters. The boundaries among CNA, PNA, and VTA were delineated based on H&E stain images, and MVD was assessed for each subregion of each VX2 tumor based. There were no correlations between ph-parameters (Ktrans,ve, and vp) and MVD for CNA. For PNA, the Ktrans values were positively correlated with the MVD (r=0.8124,p<0.0001). For VTA, we found a positive correlation between Ktrans values and the MVD (r=0.5743,p<0.05). Measuring ...

Oncotarget, Jan 14, 2016

This study aimed to investigate the effect of oral antiviral treatment on the prognosis of hepati... more This study aimed to investigate the effect of oral antiviral treatment on the prognosis of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) after radiofrequency (RF) ablation. Between January 2003 and December 2010, 228 patients without a history of antiviral treatment were treated with RF ablation for a single HBV-related HCC. We divided the patients into two groups, patients who received (n=125) or did not receive antiviral treatment (n=103), based on whether oral antiviral treatment was administered after RF ablation. The median duration of antiviral treatment was 60.1 months. HCC recurrence and overall survival were compared in the two groups in the full cohort and the propensity score-matched cohort. In the matched cohort, the probability of HCC recurrence at 5 years was 43.8% for the non-antiviral treatment group and 14.7% for the antiviral treatment group (p<0.001). The probability of overall survival at 5 years was 77.2% for the non-antiviral treatment group...

Radiology, Jul 29, 2016

Purpose To compare the long-term therapeutic outcomes of radiofrequency (RF) ablation for hepatoc... more Purpose To compare the long-term therapeutic outcomes of radiofrequency (RF) ablation for hepatocellular carcinoma (HCC) in subcapsular versus nonsubcapsular locations by using propensity score matching. Materials and Methods RF ablation for subcapsular HCC is controversial because of a high risk of incomplete ablation or major complications. This retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Between April 2006 and December 2011, 508 consecutive patients (396 men, 112 women; age range, 30-80 years) with a single HCC (Barcelona Clinic Liver Cancer stage 0 or A) underwent ultrasonography-guided percutaneous RF ablation as a first-line treatment. The patients were divided into two groups according to tumor location: subcapsular (n = 227) and nonsubcapsular (n = 281). Subcapsular HCC was defined as an index tumor located within 0.1 cm of the liver capsule. The association of subcapsular location and therapeutic o...

Korean journal of radiology : official journal of the Korean Radiological Society

The aim of this study is to investigate the effects of cooperative training on the pretreatment a... more The aim of this study is to investigate the effects of cooperative training on the pretreatment assessment of the feasibility to perform Ultrasonography (US) guided percutaneous radiofrequency ablation for patients afflicted with hepatocellular carcinoma. In our prospective study, 146 patients with 200 hepatocellular carcinomas were referred for radiofrequency ablation after triage by hepatologists. Three radiologists with different levels of experience performed the planning US before (group I) and after (group II) cooperative training, to evaluate whether radiofrequency ablation was feasible. The feasibility rates considered eligible according to our criteria were evaluated. In addition, we analyzed the reasons for the lack of feasibility were analyzed. The interobserver agreement for the assessment of feasibility before and after training was also calculated. The overall feasibility rates for both groups was 73%. No significant difference in the feasibility rates was observed. Th...

Korean journal of radiology : official journal of the Korean Radiological Society

Percutaneous interventional procedures under image guidance, such as biopsy, ethanol injection th... more Percutaneous interventional procedures under image guidance, such as biopsy, ethanol injection therapy, and radiofrequency ablation play important roles in the management of hepatocellular carcinomas. Although uncommon, the procedures may result in tumor implantation along the needle tract, which is a major delayed complication. Implanted tumors usually appear as one or a few, round or oval-shaped, enhancing nodules along the needle tract on CT, from the intraperitoneum through the intercostal or abdominal muscles to the subcutaneous or cutaneous tissues. Radiologists should understand the mechanisms and risk factors of needle tract implantation, minimize this complication, and also pay attention to the presence of implanted tumors along the needle tract during follow-up.

Korean journal of radiology : official journal of the Korean Radiological Society

To assess the technical feasibility and local efficacy of biplane fluoroscopy plus US-guided perc... more To assess the technical feasibility and local efficacy of biplane fluoroscopy plus US-guided percutaneous radiofrequency ablation (RFA) for viable hepatocellular carcinoma (HCC) around retained iodized oil after transcatheter arterial chemoembolization (TACE). Our prospective study was approved by our institutional review board and informed consent was obtained from all participating patients. For patients with viable HCC around retained iodized oil after TACE, biplane fluoroscopy plus US-guided RFA was performed. We evaluated the rate of technical success and major complications on a post-RFA CT examination and local tumor progression with a follow-up CT. Among 40 consecutive patients, 19 were excluded due to one of the following reasons: poorly visible HCC on fluoroscopy (n = 13), high risk location (n = 2), RFA performed under monoplane fluoroscopy and US guidance (n = 2), and poorly identifiable new HCCs on US (n = 2). The remaining 21 patients with 21 viable HCCs were included....

Clinical and Molecular Hepatology, 2014

Background/Aims: To determine the value of fusion imaging with contrast-enhanced ultrasonography ... more Background/Aims: To determine the value of fusion imaging with contrast-enhanced ultrasonography (CEUS) and computed tomography (CT)/magnetic resonance (MR) images for percutaneous radiofrequency ablation (RFA) of very-early-stage hepatocellular carcinomas (HCCs) that are inconspicuous on fusion imaging with B-mode ultrasound (US) and CT/MR images. Methods: This retrospective study was approved by our institutional review board and the requirement for informed consent was waived. Fusion imaging with CEUS using Sonazoid contrast agent and CT/MR imaging was performed on HCCs (<2 cm) that were inconspicuous on fusion imaging with B-mode US. We evaluated the number of cases that became conspicuous on fusion imaging with CEUS. Percutaneous RFA was performed under the guidance of fusion imaging with CEUS. Technical success and major complication rates were assessed. Results: In total, 30 patients with 30 HCCs (mean, 1.2 cm; range, 0.6-1.7 cm) were included, among which 25 (83.3%) became conspicuous on fusion imaging with CEUS at the time of the planning US and/or RFA procedure. Of those 25 HCCs, RFA was considered feasible for 23 (92.0%), which were thus treated. The technical success and major complication rates were 91.3% (21/23) and 4.3% (1/23), respectively. Conclusions: Fusion imaging with CEUS and CT/MR imaging is highly effective for percutaneous RFA of very-earlystage HCCs inconspicuous on fusion imaging with B-mode US and CT/MR imaging.

AIM: To evaluate the long-term results of radiofrequency ablation (RFA) compared to left lateral ... more AIM: To evaluate the long-term results of radiofrequency ablation (RFA) compared to left lateral sectionectomy (LLS) in patients with Child-Pugh class A disease for the treatment of single and small hepatocellular carcinoma (HCC) in the left lateral segments. METHODS: We retrospectively reviewed the data of 133 patients with single HCC (≤ 3 cm) in their left lateral segments who underwent curative LLS (n = 66) or RFA (n = 67) between 2006 and 2010. RESULTS: The median follow-up period was 33.5 mo in the LLS group and 29 mo in the RFA group (P = 0.060). Most patients had hepatitis B virus-related HCC. The hospital stay was longer in the LLS group than in the RFA group (8 d vs 2 d, P < 0.001). The 1-, 2-, and 3-year disease-free survival and overall survival rates were 80.0%, 68.2%, and 60.0%, and 95.4%, 92.3%, and 92.3%, respectively, for the LLS group; and 80.8%, 59.9%, and 39.6%, and 98.2%, 92.0%, and 74.4%, respectively, for the RFA group. The disease-free survival curve and overall survival curve were higher in the LLS group than in the RFA group (P = 0.012 and P = 0.013, respectively). Increased PIVKA-Ⅱ levels and small tumor size were associated with HCC recurrence in multivariate analysis. CONCLUSION: Liver resection is suitable for single HCC ≤ 3 cm in the left lateral segments.

Hepatology international, 2011

There are insufficient data comparing long-term prognoses after radiofrequency ablation (RFA) and... more There are insufficient data comparing long-term prognoses after radiofrequency ablation (RFA) and surgery. We compared the baseline characteristics and survival rates of patients (single, ≤3 cm, and Child-Pugh class A) treated surgically (n = 215) and with RFA (n = 255) from January 2000 to December 2007 at our institution. The surgery group was characterized by younger age, higher prevalence of HBsAg, less cirrhosis, and an increased chance of Child-Pugh score of 5 and CLIP score of 1, compared to the RFA group. During the median follow-up period of 42 months (range 1-109), the 3-, 5- and 7-year overall survival rates in the surgery group were 98, 94, and 94%, respectively, which were significantly higher than those in the RFA group (92, 87, and 76%, respectively, P = 0.002). The 3- and 5-year recurrence-free survival rates were 72 and 66%, respectively, in the surgery group, which were significantly higher than those in the RFA group (34 and 24%, respectively, P < 0.001). The s...

Journal of Gastroenterology and Hepatology, 2011

Conclusions: Chronic venous insufficiency of the lower extremities is common and is associated wi... more Conclusions: Chronic venous insufficiency of the lower extremities is common and is associated with both legs in 20% of patients. Patients in this cohort had equivalent outcomes regardless of whether one or both legs were treated (in the same setting), including perioperative complications and improvement in venous clinical severity and quality-of-life scores. Thus, bilateral lower extremity radiofrequency ablation (RFA) was well tolerated and should be an option for patients. Summary: This retrospective cohort study reports outcomes following RFA from a single center in Seoul, Korea. RFA was performed on 546 limbs in 385 patients over a 4-year time period. Unilateral RFA was performed in 65.1% and bilateral, same setting RFA in 34.9%. In this cohort of patients with CVI, ablation was performed on 58.2% of 1 vein, 37.9% of 2 veins, 2.9% of 3 veins, and 1% of 4 veins. The procedures were equally performed in men and women and 71.2% under spinal or local anesthesia. At 2-year follow-up, 5.5% of the treated veins had recanalized. Also at 2 years, the postoperative clinical outcomes as measured by Clinical, Etiologic, Anatomic and Pathophysiologic (CEAP), Venous Clinical Severity Score (VCSS), and quality-of-life (QoL) scores improved significantly from preoperative measurements. When unilateral versus bilateral cases were analyzed, both had improvements in clinical scores from the preoperative to postoperative period, with the bilateral cohort reaching statistical significance. Accordingly, the VCSS score improved significantly in both groups with the bilateral pre-and postoperative scores being higher than the unilateral group. The difference in improvement in VCSS score was also greater in the bilateral group (4.01 vs. 1.87; P < .001). The QoL scores also improved significantly in both groups with no difference in magnitude of improvement. Comments: This study demonstrates that in patients with bilateral symptomatic CVI, regardless of whether endovenous ablation procedures are staged or performed simultaneously, patients do well. RFA has a low complication profile, low recanalization rate, and is associated with high patient satisfaction. The decision about how to approach the treatment of multiple veins should be an active discussion between the provider and the patient about necessity, expectations, and costs associated with multiple, possibly unnecessary, return visits for treatment.

Hepatology, 2008

According to the American Association for the Study of Liver Diseases guidelines, percutaneous et... more According to the American Association for the Study of Liver Diseases guidelines, percutaneous ethanol injection (PEI) is a safe and highly effective treatment for small hepatocellular carcinomas (HCC) and should be the standard against which any new therapy is compared. The primary purpose of this study was to identify survival benefit of any percutaneous ablation therapy as compared with PEI in the treatment of patients with unresectable HCC. The secondary endpoints were initial tumor response, local tumor progression, and complications. Randomized controlled trials that compared pecutaneous ablative therapies with PEI were included. MEDLINE, the Cochrane Library, CANCERLIT, and manual search from 1978 to July 2008 were used. To control the potential heterogeneity, the random effects model of DerSimonian and Laird was used for a meta-analysis. Egger's test was performed to test a potential publication bias. We identified seven randomized controlled trials (RCTs), but only four RCTs including 652 patients that compared radiofrequency ablation (RFA) with PEI met the inclusion criteria to perform a meta-analysis assessing 3-year survival. A meta-analysis of the four RCTs demonstrated a significant improvement in 3-year survival favoring RFA over PEI (odds ratio 0.477, 95% confidence interval 0.340-0.670; P < 0.001). Heterogeneity among the four trials was not significant (Q ‫؍‬ 4.586; P‫؍‬ 0.205). Egger's test revealed that the publication bias was not significant (P ‫؍‬ 0.647). However, the number of patients included in the analysis was insufficient for a robust meta-analysis of initial tumor response. The definition of local tumor progression or major complication was not unified among the trials included in the meta-analysis. Conclusion: RFA demonstrated significantly improved 3-year survival status for patients with HCC, when compared to PEI. (HEPATOLOGY 2009;49:453-459.)

European Radiology, 2012

Objective To evaluate the risk factors affecting early diffuse recurrence within 1 year of percut... more Objective To evaluate the risk factors affecting early diffuse recurrence within 1 year of percutaneous ultrasound-guided radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). Methods Out of 146 patients who received transcatheter arterial chemoembolisation (TACE) for treatment of recurrent HCC after percutaneous ultrasound-guided RFA, we selected 23 patients with early diffuse recurrence. Early diffuse recurrence was defined as three or more new recurrent HCCs within 1 year of initial RFA. As a control group, we selected 23 patients, matched exactly for age and sex, in which there was no local tumour progression or new recurrence after RFA. To analyse the risk factors, we examined patient factors and tumour factors. Results Recurrent tumours occurred from 30 to 365 days after RFA (median time, 203 days). Univariate analysis indicated that larger tumour size and poorly defined margin were significant risk factors (P<0.05). Multivariate analysis indicated that poorly defined margin was a significant risk factor (P<0.05). Conclusion Larger tumour size and poorly defined margin may be risk factors for early diffuse recurrence of HCC within 1 year of RFA. Tumours with such risk factors should be treated with a combination of TACE to minimise the potential for therapeutic failure. Key Points • Ultrasound-guided radiofrequency ablation (RFA) is widely used for hepatocellular carcinoma (HCC). • Early diffuse recurrence after RFA is an important prognostic factor • The risk factors for recurrence are larger tumour size and poorly defined margins • Tumours with such risk factors should be treated with transarterial chemoembolisation.

Annals of Surgical Oncology, 2008

Background: Intraoperative radiofrequency (RF) ablation with or without surgical resection curren... more Background: Intraoperative radiofrequency (RF) ablation with or without surgical resection currently plays one of important roles in modern hepatocellular carcinoma (HCC) therapy. We evaluated long-term follow-up results including prognostic factors of intraoperative RF ablation for HCC that was difficult to treat percutaneously. Methods: A total of 133 patients (male, 22 female, mean age 55.8 years) underwent intraoperative RF ablations for 200 HCCs (follow-up period 3.0-79.7 months, median 22.3 months). Hepatic resection was also performed in 29 patients. Reasons for the intraoperative procedure included no safe electrode path (n = 59), excessive tumor burden (n = 41), nonvisualization of the HCC on ultrasonography (n = 20), and risk of collateral thermal damage to adjacent organs (n = 13). We evaluated the technique effectiveness rate at 1 month computed tomography (CT), cumulative local tumor progression rate, cumulative disease-free and overall survival rates, and complications. We also sought significant prognostic factors for overall survival. Results: The technique effectiveness at 1 month was 94.7% (126/133). The cumulative local tumor progression rates at 1 and 3 years were 4.9% and 8.8%, respectively. The cumulative disease-free and overall survival rates at 1, 3 and 5 years were 51.8%, 21.3%, and 16.0% and 92.3%, 72.6%, and 46.5%, respectively. Major complications occurred in nine patients (6.8%). Procedure-related mortality was 1.5% (2/133). The patients treated for recurrent HCC (P = 0.003) or with high serum alpha-fetoprotein levels (P = 0.009) had poor survival by multivariate analysis. Conclusion: The results of this study showed that intraoperative radiofrequency ablation with or without hepatic resection is a safe and effective treatment for hepatocellular carcinoma in patients who are not candidates for the percutaneous approach.

Annals of Surgical Oncology, 2007

Background: For multifocal hepatocellular carcinomas (HCCs) that are untreatable with resection o... more Background: For multifocal hepatocellular carcinomas (HCCs) that are untreatable with resection only, locoregional therapies added to hepatectomy have been introduced. However, some preliminary reports have documented average survival results and relatively high complication rates. We evaluated the long-term survival results and safety of combined hepatectomy and radiofrequency ablation (RFA) in patients with HCCs and assessed the prognostic factors affecting their survival. Methods: A total of 53 patients who had 148 HCCs in their livers underwent hepatectomy combined with ultrasound-guided intraoperative RFA. The mean diameter of the 82 resected tumors was 4.8 cm (range 1.3-21.0 cm) and that of 66 ablated tumors was 1.5 cm (range 0.8-3.5 cm). We evaluated the primary effectiveness rates, survival rates, and complications. In addition, we assessed the prognostic factors associated with the survival rates using Cox proportional hazard models. Results: The primary effectiveness rate of RFA was 98% (65 of 66). Local tumor progression was observed in two (3%) ablation zones of 65 tumors with complete primary effectiveness. The cumulative survival rates at 1, 2, 3, 4, and 5 years were 87, 83, 80, 68, and 55%, respectively. Patients with smaller resected tumors (£5 cm) demonstrated better survival results (P = 0.004). No procedure-related deaths occurred. We observed hepatectomy-related complications in 4 patients (8%, 4 of 53) and an RFA-related complication in 1 patient (2%, 1 of 53). Conclusions: Combined hepatectomy and RFA is an effective and safe treatment modality for multifocal HCCs. Resected tumor size was a significant prognostic predictor of long-term survival.

American Journal of Roentgenology, 2008

A b d o m i n a l I m ag i ng • C l i n ic a l O b s e r v a t io n s

American Journal of Roentgenology, 2010

significance of bilomas that develop in the RFA zone after RFA of HCC. Materials and Methods Pati... more significance of bilomas that develop in the RFA zone after RFA of HCC. Materials and Methods Patients This study was performed with the approval of our institutional review board. Obtaining informed consent was waived because of the retrospective study design. Between April 1999 and May 2008, 2,630 patients with HCC underwent a total of 3,284 sessions of RFA at our center. The criteria used to select patients for RFA included the following: a single nodular HCC that was not greater than 5 cm in maximum diameter or fewer than three multinodular HCCs with each tumor measuring a maximum of 3 cm in diameter [14]; the absence of extrahepatic metastasis, portal vein thrombosis, gastrointestinal bleeding, encephalopathy, a large amount of ascites, and Child-Pugh class A or B status; a prothrombin time ratio greater than 50%; and a platelet count higher than 50,000/mm 3. A biloma was defined as a circumferential fluid collection found on CT in the space surrounding the necrotic tissue of the ablation zone or as a communi

American Journal of Roentgenology, 2009

R adiofrequency ablation has been used to treat hepatocellular carcinoma (HCC) worldwide and is c... more R adiofrequency ablation has been used to treat hepatocellular carcinoma (HCC) worldwide and is currently accepted as a first-line therapy for small HCC because of its excellent local therapeutic efficacy and low complication rate [1, 2]. These beneficial qualities are particularly evident in patients who have poor functional reserve of the liver, and radiofrequency ablation follows liver transplantation as the second most ideal therapeutic technique for HCC patients with poor liver function who are not candidates for hepatic resection. Despite the advantages of radiofrequency ablation, local tumor progression, which is defined as recurrence occurring either abutting or within the previous radiofrequency ablation zone, occurs in 2.4-12% of cases [1, 3-7]. Because local tumor progression is common, its prediction by means of analyzing risk factors has prognostic implications.

Korean Journal of Radiology, 2009

Objective The objective of this study was to evaluate the safety and therapeutic efficacy of perc... more Objective The objective of this study was to evaluate the safety and therapeutic efficacy of percutaneous radiofrequency (RF) ablation for the treatment of hepatocellular carcinomas (HCCs) adjacent to the gallbladder with the use of internally cooled electrodes. Materials and Methods We retrospectively assessed 45 patients with 46 HCCs (mean size, 2.2 cm) adjacent to the gallbladder (≤1.0 cm) treated with RF ablation using an internally cooled electrode system. An electrode was inserted into the tumor either parallel (n = 38) or perpendicular (n = 8) to the gallbladder wall. The safety and therapeutic efficacy of the procedures were assessed with clinical and imaging follow-up examinations. Follow-up with the use of CT ranged from four to 45 months (mean, 19 months). The association between variables (electrode direction, electrode type, tumor size, tumor location, lobar location) and the presence of a residual tumor or local tumor progression was also analyzed. Results There were n...

Korean Journal of Radiology, 2020

Objective: To evaluate the effect of perfluorobutane microbubbles (Sonazoid®, GE Healthcare) on s... more Objective: To evaluate the effect of perfluorobutane microbubbles (Sonazoid®, GE Healthcare) on steam popping during radiofrequency (RF) ablation for treating hepatocellular carcinoma (HCC), and to assess whether popping affects treatment outcomes. Materials and Methods: The institutional review board approved this retrospective study, which included 90 consecutive patients with single HCC, who received percutaneous RF ablation as the first-line treatment. The patients were divided into two groups, based on the presence or absence of the popping phenomenon, which was defined as an audible sound with a simultaneous sudden explosion within the ablation zone as detected via ultrasonography during the procedure. The factors contributing to the popping phenomenon were identified using multivariable logistic regression analysis. Local tumor progression (LTP) and disease-free survival (DFS) were assessed using the Kaplan-Meier method with the log-rank test for performing comparisons between the two groups. Results: The overall incidence of the popping phenomenon was 25.8% (24/93). Sonazoid® was used in 1 patient (4.2%) in the popping group (n = 24), while it was used in 15 patients (21.7%) in the non-popping group (n = 69). Multivariable analysis revealed that the use of Sonazoid® was the only significant factor for absence of the popping phenomenon (odds ratio = 0.10, p = 0.048). There were no significant differences in cumulative LTP and DFS between the two groups (p = 0.479 and p = 0.424, respectively). Conclusion: The use of Sonazoid® has a suppressive effect on the popping phenomenon during RF ablation in patients with HCC. However, the presence of the popping phenomenon may not affect clinical outcomes.

Journal of applied clinical medical physics, Sep 8, 2016

The purpose of this study was to examine the correlation of quantitative dynamic contrast-enhance... more The purpose of this study was to examine the correlation of quantitative dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) with microvessel density (MVD) in necrotic, partial necrotic, and viable tumors using a rabbit VX2 liver tumor model. Nine rabbits were used for this study. The complete necrotic area (CNA), partial necrotic area (PNA), and viable tumor area (VTA) of liver tumors were experimentally induced by radiofrequency ablation (RFA). DCE-MRI data were processed based on the extended Kety model to estimate Ktrans,ve and vp parameters. The boundaries among CNA, PNA, and VTA were delineated based on H&E stain images, and MVD was assessed for each subregion of each VX2 tumor based. There were no correlations between ph-parameters (Ktrans,ve, and vp) and MVD for CNA. For PNA, the Ktrans values were positively correlated with the MVD (r=0.8124,p<0.0001). For VTA, we found a positive correlation between Ktrans values and the MVD (r=0.5743,p<0.05). Measuring ...

Oncotarget, Jan 14, 2016

This study aimed to investigate the effect of oral antiviral treatment on the prognosis of hepati... more This study aimed to investigate the effect of oral antiviral treatment on the prognosis of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) after radiofrequency (RF) ablation. Between January 2003 and December 2010, 228 patients without a history of antiviral treatment were treated with RF ablation for a single HBV-related HCC. We divided the patients into two groups, patients who received (n=125) or did not receive antiviral treatment (n=103), based on whether oral antiviral treatment was administered after RF ablation. The median duration of antiviral treatment was 60.1 months. HCC recurrence and overall survival were compared in the two groups in the full cohort and the propensity score-matched cohort. In the matched cohort, the probability of HCC recurrence at 5 years was 43.8% for the non-antiviral treatment group and 14.7% for the antiviral treatment group (p<0.001). The probability of overall survival at 5 years was 77.2% for the non-antiviral treatment group...

Radiology, Jul 29, 2016

Purpose To compare the long-term therapeutic outcomes of radiofrequency (RF) ablation for hepatoc... more Purpose To compare the long-term therapeutic outcomes of radiofrequency (RF) ablation for hepatocellular carcinoma (HCC) in subcapsular versus nonsubcapsular locations by using propensity score matching. Materials and Methods RF ablation for subcapsular HCC is controversial because of a high risk of incomplete ablation or major complications. This retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Between April 2006 and December 2011, 508 consecutive patients (396 men, 112 women; age range, 30-80 years) with a single HCC (Barcelona Clinic Liver Cancer stage 0 or A) underwent ultrasonography-guided percutaneous RF ablation as a first-line treatment. The patients were divided into two groups according to tumor location: subcapsular (n = 227) and nonsubcapsular (n = 281). Subcapsular HCC was defined as an index tumor located within 0.1 cm of the liver capsule. The association of subcapsular location and therapeutic o...

Korean journal of radiology : official journal of the Korean Radiological Society

The aim of this study is to investigate the effects of cooperative training on the pretreatment a... more The aim of this study is to investigate the effects of cooperative training on the pretreatment assessment of the feasibility to perform Ultrasonography (US) guided percutaneous radiofrequency ablation for patients afflicted with hepatocellular carcinoma. In our prospective study, 146 patients with 200 hepatocellular carcinomas were referred for radiofrequency ablation after triage by hepatologists. Three radiologists with different levels of experience performed the planning US before (group I) and after (group II) cooperative training, to evaluate whether radiofrequency ablation was feasible. The feasibility rates considered eligible according to our criteria were evaluated. In addition, we analyzed the reasons for the lack of feasibility were analyzed. The interobserver agreement for the assessment of feasibility before and after training was also calculated. The overall feasibility rates for both groups was 73%. No significant difference in the feasibility rates was observed. Th...

Korean journal of radiology : official journal of the Korean Radiological Society

Percutaneous interventional procedures under image guidance, such as biopsy, ethanol injection th... more Percutaneous interventional procedures under image guidance, such as biopsy, ethanol injection therapy, and radiofrequency ablation play important roles in the management of hepatocellular carcinomas. Although uncommon, the procedures may result in tumor implantation along the needle tract, which is a major delayed complication. Implanted tumors usually appear as one or a few, round or oval-shaped, enhancing nodules along the needle tract on CT, from the intraperitoneum through the intercostal or abdominal muscles to the subcutaneous or cutaneous tissues. Radiologists should understand the mechanisms and risk factors of needle tract implantation, minimize this complication, and also pay attention to the presence of implanted tumors along the needle tract during follow-up.

Korean journal of radiology : official journal of the Korean Radiological Society

To assess the technical feasibility and local efficacy of biplane fluoroscopy plus US-guided perc... more To assess the technical feasibility and local efficacy of biplane fluoroscopy plus US-guided percutaneous radiofrequency ablation (RFA) for viable hepatocellular carcinoma (HCC) around retained iodized oil after transcatheter arterial chemoembolization (TACE). Our prospective study was approved by our institutional review board and informed consent was obtained from all participating patients. For patients with viable HCC around retained iodized oil after TACE, biplane fluoroscopy plus US-guided RFA was performed. We evaluated the rate of technical success and major complications on a post-RFA CT examination and local tumor progression with a follow-up CT. Among 40 consecutive patients, 19 were excluded due to one of the following reasons: poorly visible HCC on fluoroscopy (n = 13), high risk location (n = 2), RFA performed under monoplane fluoroscopy and US guidance (n = 2), and poorly identifiable new HCCs on US (n = 2). The remaining 21 patients with 21 viable HCCs were included....

Clinical and Molecular Hepatology, 2014

Background/Aims: To determine the value of fusion imaging with contrast-enhanced ultrasonography ... more Background/Aims: To determine the value of fusion imaging with contrast-enhanced ultrasonography (CEUS) and computed tomography (CT)/magnetic resonance (MR) images for percutaneous radiofrequency ablation (RFA) of very-early-stage hepatocellular carcinomas (HCCs) that are inconspicuous on fusion imaging with B-mode ultrasound (US) and CT/MR images. Methods: This retrospective study was approved by our institutional review board and the requirement for informed consent was waived. Fusion imaging with CEUS using Sonazoid contrast agent and CT/MR imaging was performed on HCCs (<2 cm) that were inconspicuous on fusion imaging with B-mode US. We evaluated the number of cases that became conspicuous on fusion imaging with CEUS. Percutaneous RFA was performed under the guidance of fusion imaging with CEUS. Technical success and major complication rates were assessed. Results: In total, 30 patients with 30 HCCs (mean, 1.2 cm; range, 0.6-1.7 cm) were included, among which 25 (83.3%) became conspicuous on fusion imaging with CEUS at the time of the planning US and/or RFA procedure. Of those 25 HCCs, RFA was considered feasible for 23 (92.0%), which were thus treated. The technical success and major complication rates were 91.3% (21/23) and 4.3% (1/23), respectively. Conclusions: Fusion imaging with CEUS and CT/MR imaging is highly effective for percutaneous RFA of very-earlystage HCCs inconspicuous on fusion imaging with B-mode US and CT/MR imaging.

AIM: To evaluate the long-term results of radiofrequency ablation (RFA) compared to left lateral ... more AIM: To evaluate the long-term results of radiofrequency ablation (RFA) compared to left lateral sectionectomy (LLS) in patients with Child-Pugh class A disease for the treatment of single and small hepatocellular carcinoma (HCC) in the left lateral segments. METHODS: We retrospectively reviewed the data of 133 patients with single HCC (≤ 3 cm) in their left lateral segments who underwent curative LLS (n = 66) or RFA (n = 67) between 2006 and 2010. RESULTS: The median follow-up period was 33.5 mo in the LLS group and 29 mo in the RFA group (P = 0.060). Most patients had hepatitis B virus-related HCC. The hospital stay was longer in the LLS group than in the RFA group (8 d vs 2 d, P < 0.001). The 1-, 2-, and 3-year disease-free survival and overall survival rates were 80.0%, 68.2%, and 60.0%, and 95.4%, 92.3%, and 92.3%, respectively, for the LLS group; and 80.8%, 59.9%, and 39.6%, and 98.2%, 92.0%, and 74.4%, respectively, for the RFA group. The disease-free survival curve and overall survival curve were higher in the LLS group than in the RFA group (P = 0.012 and P = 0.013, respectively). Increased PIVKA-Ⅱ levels and small tumor size were associated with HCC recurrence in multivariate analysis. CONCLUSION: Liver resection is suitable for single HCC ≤ 3 cm in the left lateral segments.

Hepatology international, 2011

There are insufficient data comparing long-term prognoses after radiofrequency ablation (RFA) and... more There are insufficient data comparing long-term prognoses after radiofrequency ablation (RFA) and surgery. We compared the baseline characteristics and survival rates of patients (single, ≤3 cm, and Child-Pugh class A) treated surgically (n = 215) and with RFA (n = 255) from January 2000 to December 2007 at our institution. The surgery group was characterized by younger age, higher prevalence of HBsAg, less cirrhosis, and an increased chance of Child-Pugh score of 5 and CLIP score of 1, compared to the RFA group. During the median follow-up period of 42 months (range 1-109), the 3-, 5- and 7-year overall survival rates in the surgery group were 98, 94, and 94%, respectively, which were significantly higher than those in the RFA group (92, 87, and 76%, respectively, P = 0.002). The 3- and 5-year recurrence-free survival rates were 72 and 66%, respectively, in the surgery group, which were significantly higher than those in the RFA group (34 and 24%, respectively, P < 0.001). The s...

Journal of Gastroenterology and Hepatology, 2011

Conclusions: Chronic venous insufficiency of the lower extremities is common and is associated wi... more Conclusions: Chronic venous insufficiency of the lower extremities is common and is associated with both legs in 20% of patients. Patients in this cohort had equivalent outcomes regardless of whether one or both legs were treated (in the same setting), including perioperative complications and improvement in venous clinical severity and quality-of-life scores. Thus, bilateral lower extremity radiofrequency ablation (RFA) was well tolerated and should be an option for patients. Summary: This retrospective cohort study reports outcomes following RFA from a single center in Seoul, Korea. RFA was performed on 546 limbs in 385 patients over a 4-year time period. Unilateral RFA was performed in 65.1% and bilateral, same setting RFA in 34.9%. In this cohort of patients with CVI, ablation was performed on 58.2% of 1 vein, 37.9% of 2 veins, 2.9% of 3 veins, and 1% of 4 veins. The procedures were equally performed in men and women and 71.2% under spinal or local anesthesia. At 2-year follow-up, 5.5% of the treated veins had recanalized. Also at 2 years, the postoperative clinical outcomes as measured by Clinical, Etiologic, Anatomic and Pathophysiologic (CEAP), Venous Clinical Severity Score (VCSS), and quality-of-life (QoL) scores improved significantly from preoperative measurements. When unilateral versus bilateral cases were analyzed, both had improvements in clinical scores from the preoperative to postoperative period, with the bilateral cohort reaching statistical significance. Accordingly, the VCSS score improved significantly in both groups with the bilateral pre-and postoperative scores being higher than the unilateral group. The difference in improvement in VCSS score was also greater in the bilateral group (4.01 vs. 1.87; P < .001). The QoL scores also improved significantly in both groups with no difference in magnitude of improvement. Comments: This study demonstrates that in patients with bilateral symptomatic CVI, regardless of whether endovenous ablation procedures are staged or performed simultaneously, patients do well. RFA has a low complication profile, low recanalization rate, and is associated with high patient satisfaction. The decision about how to approach the treatment of multiple veins should be an active discussion between the provider and the patient about necessity, expectations, and costs associated with multiple, possibly unnecessary, return visits for treatment.

Hepatology, 2008

According to the American Association for the Study of Liver Diseases guidelines, percutaneous et... more According to the American Association for the Study of Liver Diseases guidelines, percutaneous ethanol injection (PEI) is a safe and highly effective treatment for small hepatocellular carcinomas (HCC) and should be the standard against which any new therapy is compared. The primary purpose of this study was to identify survival benefit of any percutaneous ablation therapy as compared with PEI in the treatment of patients with unresectable HCC. The secondary endpoints were initial tumor response, local tumor progression, and complications. Randomized controlled trials that compared pecutaneous ablative therapies with PEI were included. MEDLINE, the Cochrane Library, CANCERLIT, and manual search from 1978 to July 2008 were used. To control the potential heterogeneity, the random effects model of DerSimonian and Laird was used for a meta-analysis. Egger's test was performed to test a potential publication bias. We identified seven randomized controlled trials (RCTs), but only four RCTs including 652 patients that compared radiofrequency ablation (RFA) with PEI met the inclusion criteria to perform a meta-analysis assessing 3-year survival. A meta-analysis of the four RCTs demonstrated a significant improvement in 3-year survival favoring RFA over PEI (odds ratio 0.477, 95% confidence interval 0.340-0.670; P < 0.001). Heterogeneity among the four trials was not significant (Q ‫؍‬ 4.586; P‫؍‬ 0.205). Egger's test revealed that the publication bias was not significant (P ‫؍‬ 0.647). However, the number of patients included in the analysis was insufficient for a robust meta-analysis of initial tumor response. The definition of local tumor progression or major complication was not unified among the trials included in the meta-analysis. Conclusion: RFA demonstrated significantly improved 3-year survival status for patients with HCC, when compared to PEI. (HEPATOLOGY 2009;49:453-459.)

European Radiology, 2012

Objective To evaluate the risk factors affecting early diffuse recurrence within 1 year of percut... more Objective To evaluate the risk factors affecting early diffuse recurrence within 1 year of percutaneous ultrasound-guided radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). Methods Out of 146 patients who received transcatheter arterial chemoembolisation (TACE) for treatment of recurrent HCC after percutaneous ultrasound-guided RFA, we selected 23 patients with early diffuse recurrence. Early diffuse recurrence was defined as three or more new recurrent HCCs within 1 year of initial RFA. As a control group, we selected 23 patients, matched exactly for age and sex, in which there was no local tumour progression or new recurrence after RFA. To analyse the risk factors, we examined patient factors and tumour factors. Results Recurrent tumours occurred from 30 to 365 days after RFA (median time, 203 days). Univariate analysis indicated that larger tumour size and poorly defined margin were significant risk factors (P<0.05). Multivariate analysis indicated that poorly defined margin was a significant risk factor (P<0.05). Conclusion Larger tumour size and poorly defined margin may be risk factors for early diffuse recurrence of HCC within 1 year of RFA. Tumours with such risk factors should be treated with a combination of TACE to minimise the potential for therapeutic failure. Key Points • Ultrasound-guided radiofrequency ablation (RFA) is widely used for hepatocellular carcinoma (HCC). • Early diffuse recurrence after RFA is an important prognostic factor • The risk factors for recurrence are larger tumour size and poorly defined margins • Tumours with such risk factors should be treated with transarterial chemoembolisation.

Annals of Surgical Oncology, 2008

Background: Intraoperative radiofrequency (RF) ablation with or without surgical resection curren... more Background: Intraoperative radiofrequency (RF) ablation with or without surgical resection currently plays one of important roles in modern hepatocellular carcinoma (HCC) therapy. We evaluated long-term follow-up results including prognostic factors of intraoperative RF ablation for HCC that was difficult to treat percutaneously. Methods: A total of 133 patients (male, 22 female, mean age 55.8 years) underwent intraoperative RF ablations for 200 HCCs (follow-up period 3.0-79.7 months, median 22.3 months). Hepatic resection was also performed in 29 patients. Reasons for the intraoperative procedure included no safe electrode path (n = 59), excessive tumor burden (n = 41), nonvisualization of the HCC on ultrasonography (n = 20), and risk of collateral thermal damage to adjacent organs (n = 13). We evaluated the technique effectiveness rate at 1 month computed tomography (CT), cumulative local tumor progression rate, cumulative disease-free and overall survival rates, and complications. We also sought significant prognostic factors for overall survival. Results: The technique effectiveness at 1 month was 94.7% (126/133). The cumulative local tumor progression rates at 1 and 3 years were 4.9% and 8.8%, respectively. The cumulative disease-free and overall survival rates at 1, 3 and 5 years were 51.8%, 21.3%, and 16.0% and 92.3%, 72.6%, and 46.5%, respectively. Major complications occurred in nine patients (6.8%). Procedure-related mortality was 1.5% (2/133). The patients treated for recurrent HCC (P = 0.003) or with high serum alpha-fetoprotein levels (P = 0.009) had poor survival by multivariate analysis. Conclusion: The results of this study showed that intraoperative radiofrequency ablation with or without hepatic resection is a safe and effective treatment for hepatocellular carcinoma in patients who are not candidates for the percutaneous approach.

Annals of Surgical Oncology, 2007

Background: For multifocal hepatocellular carcinomas (HCCs) that are untreatable with resection o... more Background: For multifocal hepatocellular carcinomas (HCCs) that are untreatable with resection only, locoregional therapies added to hepatectomy have been introduced. However, some preliminary reports have documented average survival results and relatively high complication rates. We evaluated the long-term survival results and safety of combined hepatectomy and radiofrequency ablation (RFA) in patients with HCCs and assessed the prognostic factors affecting their survival. Methods: A total of 53 patients who had 148 HCCs in their livers underwent hepatectomy combined with ultrasound-guided intraoperative RFA. The mean diameter of the 82 resected tumors was 4.8 cm (range 1.3-21.0 cm) and that of 66 ablated tumors was 1.5 cm (range 0.8-3.5 cm). We evaluated the primary effectiveness rates, survival rates, and complications. In addition, we assessed the prognostic factors associated with the survival rates using Cox proportional hazard models. Results: The primary effectiveness rate of RFA was 98% (65 of 66). Local tumor progression was observed in two (3%) ablation zones of 65 tumors with complete primary effectiveness. The cumulative survival rates at 1, 2, 3, 4, and 5 years were 87, 83, 80, 68, and 55%, respectively. Patients with smaller resected tumors (£5 cm) demonstrated better survival results (P = 0.004). No procedure-related deaths occurred. We observed hepatectomy-related complications in 4 patients (8%, 4 of 53) and an RFA-related complication in 1 patient (2%, 1 of 53). Conclusions: Combined hepatectomy and RFA is an effective and safe treatment modality for multifocal HCCs. Resected tumor size was a significant prognostic predictor of long-term survival.

American Journal of Roentgenology, 2008

A b d o m i n a l I m ag i ng • C l i n ic a l O b s e r v a t io n s

American Journal of Roentgenology, 2010

significance of bilomas that develop in the RFA zone after RFA of HCC. Materials and Methods Pati... more significance of bilomas that develop in the RFA zone after RFA of HCC. Materials and Methods Patients This study was performed with the approval of our institutional review board. Obtaining informed consent was waived because of the retrospective study design. Between April 1999 and May 2008, 2,630 patients with HCC underwent a total of 3,284 sessions of RFA at our center. The criteria used to select patients for RFA included the following: a single nodular HCC that was not greater than 5 cm in maximum diameter or fewer than three multinodular HCCs with each tumor measuring a maximum of 3 cm in diameter [14]; the absence of extrahepatic metastasis, portal vein thrombosis, gastrointestinal bleeding, encephalopathy, a large amount of ascites, and Child-Pugh class A or B status; a prothrombin time ratio greater than 50%; and a platelet count higher than 50,000/mm 3. A biloma was defined as a circumferential fluid collection found on CT in the space surrounding the necrotic tissue of the ablation zone or as a communi

American Journal of Roentgenology, 2009

R adiofrequency ablation has been used to treat hepatocellular carcinoma (HCC) worldwide and is c... more R adiofrequency ablation has been used to treat hepatocellular carcinoma (HCC) worldwide and is currently accepted as a first-line therapy for small HCC because of its excellent local therapeutic efficacy and low complication rate [1, 2]. These beneficial qualities are particularly evident in patients who have poor functional reserve of the liver, and radiofrequency ablation follows liver transplantation as the second most ideal therapeutic technique for HCC patients with poor liver function who are not candidates for hepatic resection. Despite the advantages of radiofrequency ablation, local tumor progression, which is defined as recurrence occurring either abutting or within the previous radiofrequency ablation zone, occurs in 2.4-12% of cases [1, 3-7]. Because local tumor progression is common, its prediction by means of analyzing risk factors has prognostic implications.