Dongil Choi

Gadoxetic Acid–Enhanced MRI Versus Triple-Phase MDCT for the Preoperative Detection of Hepatocellular Carcinoma

OBJECTIVE We compared the diagnostic performance of gadoxetic acid-enhanced MRI with that of triple-phase 16-, 40-, and 64-MDCT in the preoperative detection of hepatocellular carcinoma (HCC). SUBJECTS AND METHODS Sixty-two consecutively registered patients (54 men, eight women; age range, 31-67 years) with 83 HCCs underwent triple-phase (arterial, portal venous, equilibrium) CT at 16-, 40-, or 64-MDCT and gadoxetic acid-enhanced 3-T MRI. The diagnosis of HCC was established after surgical resection. Three observers independently and randomly reviewed the MR and CT images on a tumor-by-tumor basis. The diagnostic accuracy of these techniques in the detection of HCC was assessed with alternative free response receiver operating characteristic (ROC) analysis. Sensitivity, positive and negative predictive values, and sensitivity according to tumor size were evaluated. RESULTS For each observer, the areas under the ROC curve were 0.971, 0.959, and 0.967 for MRI and 0.947, 0.950, and 0.943 for CT. The differences were not statistically significant between the two techniques for each observer (p > 0.05). The differences in sensitivity and positive and negative predictive values between the two techniques for each observer were not statistically significant (p > 0.05). Among 10 HCCs 1 cm in diameter or smaller, each of the observers detected seven tumors with MRI. With CT, one observer detected five, one observer detected four, and one observer detected three HCCs with no statistically significant difference (p > 0.05). CONCLUSION Gadoxetic acid-enhanced MRI and triple-phase MDCT have similar diagnostic performance in the preoperative detection of HCC, but MRI may be better than MDCT in the detection of HCC 1 cm in diameter or smaller.

Ten-year outcomes of percutaneous radiofrequency ablation as first-line therapy of early hepatocellular carcinoma: Analysis of prognostic factors

BACKGROUND & AIMS The aim was to assess 10-year outcomes of radiofrequency ablation as a first-line therapy of early-stage hepatocellular carcinoma with an analysis of prognostic factors. METHODS From April 1999 to April 2011, 1305 patients (male:female=993:312; mean age, 58.4 years) with 1502 early-stage hepatocellular carcinomas (mean size, 2.2 cm) were treated with percutaneous radiofrequency ablation as a first-line option. Follow-up period ranged from 0.4 to 146.6 months (median, 33.4 months). We assessed the 10-year follow-up results of recurrences and survival with the analyses of prognostic factors. RESULTS Recurrences occurred in 795 patients (1-17 times), which were managed with various therapeutic modalities. The cumulative local tumor progression rates were 27.0% and 36.9% at 5 and 10 years, respectively, for which the only significant risk factor was large tumor size (B=0.584, p=0.001). Cumulative intrahepatic distant and extrahepatic recurrence rates were 73.1% and 88.5%, and 19.1% and 38.2% at 5 and 10 years, respectively. Corresponding overall survival rates were 59.7% and 32.3%, respectively. Poor survival was associated with old age (B=0.043, p=0.010), Child-Pugh class B (B=-1.054, p<0.001), absence of antiviral therapy during follow-up (B=-0.699, p=0.034), and presence of extrahepatic recurrence (B=0.971, p=0.007). CONCLUSIONS Ten-year survival outcomes after percutaneous radiofrequency ablation as a first-line therapy of hepatocellular carcinoma were excellent despite frequent tumor recurrences. Overall survival was influenced by age, Child-Pugh class, antiviral therapy, or extrahepatic recurrence.

The Minimal Ablative Margin of Radiofrequency Ablation of Hepatocellular Carcinoma (> 2 and < 5 cm) Needed to Prevent Local Tumor Progression: 3D Quantitative Assessment Using CT Image Fusion

OBJECTIVE The aim of this study was to elucidate the minimal ablative margin for percutaneous radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) (> 2 and < 5 cm) needed to prevent local tumor progression using CT image fusion and a 3D quantitative method. MATERIALS AND METHODS From April 2005 to March 2007, we performed percutaneous RFA for the treatment of 382 HCCs larger than 2 cm and smaller than 5 cm. A total of 110 tumors in 103 patients (77 men and 26 women; mean age, 59.7 years) that were previously untreated and were monitored for at least 1 year were retrospectively enrolled. A 5-mm safety margin was attempted in all cases, and a CT finding of complete replacement of the index tumor by RFA zone was defined as technical success. We constructed fusion images of CT images obtained before and after RFA and performed radial multiplanar reformation with the rotation axis at the center of the tumor to analyze the ablative margin quantitatively. Risk factors for local tumor progression (the thinnest ablative margin, tumor size, and the effect of hepatic vessels) were assessed by multivariate analysis. RESULTS Patients underwent follow-up for 12.9-46.6 months (median, 28.1 months). The tumors were 2.1-4.8 cm (mean +/- SD, 2.7 +/- 0.6 cm) in diameter. The thinnest ablative margins ranged from 0 to 6 mm (1.0 +/- 1.4 mm). A 5-mm safety margin was achieved in only 2.7% (3/110) of cases. In 47.3% (52/110) of cases, vessel-induced indentation of the ablation zone contributed to the thinnest ablative margins. Local tumor progression was detected in 27.3% (30/110) of cases. Concordance between local tumor progression and the thinnest margin was observed in 83.3% (25/30) of cases. The incidence of concordant local tumor progression was 22.7% (25/110), 18.9% (10/53), 5.9% (2/34), and 0% (0/15) in tumors with the thinnest ablative margin of > or = 0, > or = 1, > or = 2, and > or = 3 mm, respectively. An insufficient ablative margin was the sole significant factor associated with local tumor progression. CONCLUSION When the thickness of the ablative margin is evaluated by CT image fusion, a margin of 3 mm or more appears to be associated with a lower rate of local tumor progression after percutaneous RFA of HCC.

Small Hepatocellular Carcinomas: Improved Sensitivity by Combining Gadoxetic Acid–enhanced and Diffusion-weighted MR Imaging Patterns

PURPOSE To determine if the combination of gadoxetic acid-enhanced magnetic resonance (MR) imaging and diffusion-weighted (DW) imaging helps to increase accuracy and sensitivity in the diagnosis of small hepatocellular carcinomas (HCCs) compared with those achieved by using each MR imaging technique alone. MATERIALS AND METHODS The institutional review board approved this retrospective study and waived the requirement for informed consent. The study included 130 patients (95 men, 35 women) with 179 surgically confirmed small HCCs (≤2.0 cm) and 130 patients with cirrhosis (90 men, 40 women) without HCC who underwent gadoxetic acid-enhanced MR imaging and DW imaging at 3.0 T between May 2009 and July 2010. Three sets of images were analyzed independently by three observers to detect HCC: a gadoxetic acid set (unenhanced, early dynamic, and hepatobiliary phases), a DW imaging set, and a combined set. Data were analyzed by using alternative-free response receiver operating characteristic analysis. Diagnostic accuracy (area under the receiver operating characteristic curve [A(z)]), sensitivity, specificity, and positive predictive value were calculated. RESULTS The mean A(z) values for the combined set (0.952) were significantly higher than those for the gadoxetic acid set (A(z) = 0.902) or the DW imaging set alone (A(z) = 0.871) (P ≤ .008). On a per-lesion basis, observers showed higher sensitivity in their analyses of the combined set (range, 91.1%-93.3% [163-167 of 179]) than in those of the gadoxetic acid set (range, 80.5%-82.1% [144-147 of 179]) or the DW imaging set alone (range, 77.7%-79.9% [139-143 of 179]) (P ≤ .003). Positive predictive values and specificity for all observers were equivalent for the three imaging sets. CONCLUSION The combination of gadoxetic acid-enhanced MR imaging and DW imaging yielded better diagnostic accuracy and sensitivity in the detection of small HCCs than each MR imaging technique alone.

Trastuzumab treatment improves brain metastasis outcomes through control and durable prolongation of systemic extracranial disease in HER2-overexpressing breast cancer patients

In patients with human epidermal growth factor receptor-2 (HER2)-overexpressing breast cancer, treatment with trastuzumab has been shown to markedly improve the outcome. We investigated the role of trastuzumab on brain metastasis (BM) in HER2-positive breast cancer patients. From 1999 to 2006, 251 patients were treated with palliative chemotherapy for HER2-positive metastatic breast cancer at Samsung Medical Center. The medical records of these patients were analysed to study the effects of trastuzumab on BM prevalence and outcomes. Patients were grouped according to trastuzumab therapy: pre-T (no trastuzumab therapy) vs post-T (trastuzumab therapy). The development of BM between the two treatment groups was significantly different (37.8% for post-T vs 25.0% for pre-T, P=0.028). Patients who had received trastuzumab had longer times to BM compared with patients who were not treated with trastuzumab (median 15 months for post-T group vs 10 months for pre-T group, P=0.035). Time to death (TTD) from BM was significantly longer in the post-T group than in the pre-T group (median 14.9 vs 4.0 months, P=0.0005). Extracranial disease control at the time of BM, 12 months or more of progression-free survival of extracranial disease and treatment with lapatinib were independent prognostic factors for TTD from BM.

Clinical Outcomes of Hepatic Resection and Radiofrequency Ablation in Patients With Solitary Colorectal Liver Metastasis

Background The role of the radiofrequency ablation (RFA) in treatment of solitary liver metastasis has not been established yet. Both hepatic resection (HR) and RFA have been used increasingly in the treatment of colorectal liver metastases. Study A systemic review was performed to determine the impact of treatment modality of solitary liver metastasis on recurrence patterns, disease-free survival, and overall survival (OS) rates. Results Solitary liver metastases were treated by HR in 116 patients (75.8%) and 37 patients (24.2%) were treated with RFA. Prognostic factors, recurrence rate, recurrence patterns, and survival rates were analyzed. The cumulative 3-year and 5-year local recurrence free survival rates were markedly higher in the HR group (88.0% and 84.6%) as compared with those in the RFA group [53.3% and 42.6%, respectively (P≤0.001)]. The 5-year OS rate was lower in the RFA group as compared with the HR group without statistical significance (5-year OS, 65.7% in the HR, 48.5% in the RFA group, P=0.227). Conclusions Despite of higher local recurrence rate, RFA may be considered as a therapeutic option for patients who are considered unsuitable for conventional surgical treatment. Randomized prospective controlled trials comparing the therapeutic outcome of RFA and HR are definitely warranted.

Percutaneous Radiofrequency Ablation with Artificial Ascites for Hepatocellular Carcinoma in the Hepatic Dome: Initial Experience

OBJECTIVE Our objective was to assess the feasibility, safety, and efficacy of percutaneous radiofrequency ablation with artificial ascites for hepatocellular carcinoma (HCC) in the hepatic dome. MATERIALS AND METHODS Sonographically guided percutaneous radiofrequency ablation with artificial ascites was performed in 25 patients with 34 HCCs using an internally cooled electrode radiofrequency system. At least one hepatic dome tumor in each patient was considered difficult to treat percutaneously because of partially visible tumor (n = 16) or poor electrode path (n = 9) on planning sonography. We artificially induced ascites before radiofrequency ablation by dripping 5% dextrose in water (D/W) solution to improve tumor visibility or electrode path and to separate the radiofrequency ablation zone from the diaphragm. We assessed the technical feasibility, safety, and efficacy of this technique with clinical and CT follow-up for at least 4 months (mean, 281.4 days) RESULTS Artificial ascites was successfully achieved in 22 (88%) of 25 patients with the administration of a mean of 348 mL of D/W solution for an additional mean time of 9.3 minutes. There was substantial improvement in the visibility in 93.4% (15/16) of the partially visible tumors and in achieving a better path in 77.8% (7/9) of the tumors with a poor electrode path. The primary technique effectiveness rate for hepatic dome tumors was 96% (24/25) at 1-month follow-up CT. There was no diaphragmatic thermal injury in all but one case. No complication related to artificial ascites occurred during the follow-up period. CONCLUSION Percutaneous radiofrequency ablation with artificial ascites appears a feasible, safe, and effective technique for treating HCC of the hepatic dome.

Spectrum of CT Findings after Radiofrequency Ablation of Hepatic Tumors

Image-guided radiofrequency (RF) ablation has been used to treat both resectable and nonresectable hepatic tumors. A precise imaging assessment of the therapeutic response and of any complications is mandatory after ablation. Contrast material-enhanced ultrasonography, computed tomography (CT), and magnetic resonance imaging all may be useful for this assessment. At most institutions, a three-phase contrast-enhanced CT examination is performed immediately or within 1 month after RF ablation to assess the technical success of treatment. If ablation was technically successful, three-phase CT may be repeated at 3-month intervals for evaluation of tumor recurrence. The typical CT finding in the zone subjected to RF ablation is an area of low attenuation that encompasses the tumor and an ablative margin. However, the appearance of the ablative zone may vary greatly, depending on the success of treatment and the time elapsed after the procedure. Ringlike enhancement representing benign reactive hyperemia around the ablation zone, central high-attenuation areas representing greater cellular disruption, and tiny air bubbles frequently are seen at immediate follow-up CT but usually have disappeared by the first or second follow-up examination. The successfully ablated zone gradually involutes. The appearance of the zone differs when residual tumor tissue or local tumor progression is present. Immediate or delayed complications also may be seen at follow-up CT. Radiologists must be familiar with both typical and atypical CT findings and their clinical significance. (c) RSNA, 2008.

White-matter change in mesial temporal sclerosis : Correlation of MRI with PET, pathology, and clinical features

Summary: Purpose: To assess the magnetic resonance imaging (MRI), positron emission tomography (PET), pathology, and clinical findings of patients with the MRI feature of white‐matter change (WMC) in the anterior temporal lobe.

Percutaneous Radiofrequency Ablation of Hepatocellular Carcinoma: Fusion Imaging Guidance for Management of Lesions With Poor Conspicuity at Conventional Sonography

OBJECTIVE The purpose of this study was to determine whether fusion imaging-guided percutaneous radiofrequency ablation (RFA) is effective in the management of hepatocellular carcinoma (HCC) that has poor conspicuity at conventional sonography. SUBJECTS AND METHODS Percutaneous RFA of HCC with poor conspicuity was performed under fusion imaging guidance. The time needed for image fusion between the ultrasound and CT or MR images was recorded. The quality of image fusion and the degree of operator confidence in identifying the index tumor were graded on 4-point scales. Technical success and procedure-related complications were evaluated with liver CT immediately after RFA. RESULTS Thirty patients with HCC (1.0 ± 0.3 cm) were enrolled. Twenty-seven of the 30 lesions detected at planning ultrasound were identified with fusion imaging. Of the 30 HCC candidate lesions detected with ultrasound, five were found to be pseudolesions close to the index tumor. The time needed for image fusion for the 27 lesions was 3.7 ± 2.1 minutes (range, 1.3-9.0 minutes). The quality of image fusion was graded 3.4 ± 0.6, and the degree of operator confidence in identifying the 30 HCCs, 3.3 ± 0.9. The technical success rate was 90% (27/30) in intention-to-treat analysis and 100% in analysis of actually treated lesions. There were no major RFA-related complications. CONCLUSION Fusion imaging-guided percutaneous RFA is effective in the management of HCC that has poor ultrasound conspicuity.