Safety and Efficacy of Drug-Eluting Beads Trans-Arterial Chemoembolization for Hepatocellular Carcinoma in Taiwan (SERENADE-T).

Purpose: The aim of this retrospective study was to evaluate the safety and efficacy of patients with hepatocellular carcinoma treated with drug-eluting bead with doxorubicin transarterial chemoembolization (DEBDOX-TACE) in Taiwan. Patients and Methods: We retrospectively investigated 630 hepatocellular carcinoma patients who underwent DEBDOX-TACE in multiple institutions from 2011 to 2016 in Taiwan. Tumor response was assessed per modified response evaluation criteria in solid tumors, overall survival, and safety. Results: This study included 630 patients who underwent DEBDOX-TACE, participants' mean age was 66 years, 68.1% males and 15.6% females. The mean doxorubicin dose administered via DEBDOX-TACE was 56 mg. Complete and partial response rates were 14.6% and 49.2%, respectively, with a disease control rate of 84.6%. The median overall survival was 29.2 months. The most common post-embolization symptom was abdominal pain (22.4%). No hepatic encephalopathy and no procedure-related death were found. Conclusion: Real-world data from Taiwan demonstrated that DEBDOX-TACE for hepatocellular carcinoma can achieve high tumor response rate with low adverse events.

Phase I Dose-Escalation Study of Tirapazamine Chemoembolization for Unresectable Early- and Intermediate-Stage Hepatocellular Carcinoma.

PURPOSE: To investigate the safety of replacing doxorubicin with tirapazamine in conventional transarterial chemoembolization (TACE) in an Asian population with hepatocellular carcinoma (HCC), and to determine the optimal tirapazamine dose for phase II studies. MATERIALS AND METHODS: This was a phase I, 3 + 3 dose-escalation study for patients with unresectable early- and intermediate-stage HCC who received 5, 10, or 20 mg/m2 of intra-arterial (IA) tirapazamine followed by ethiodized oil/gelatin sponge-based embolization. Key eligibilities included HCCs no more than 10 cm in diameter, prior embolization allowed, Eastern Cooperative Oncology Group performance status of 0 or 1, Child-Pugh score of 5-7, and platelet count of ≥60,000 µL. Dose-limiting toxicity (DLT) was defined as any grade 3 nonhematological or grade 4 hematological toxicity, with the exception of transient elevation of aminotransferase levels after the procedure. RESULTS: Seventeen patients were enrolled, 59% of whom had progression from a prior HCC therapy and 35% of whom had progression or recurrence after TACE. All patients tolerated the tirapazamine TACE well without any DLT or serious adverse event. Using the modified Response Evaluation Criteria in Solid Tumors, the complete response (CR) rate was 47%, and the CR + partial response rate was 65%. The median duration of response was not reached. The median time to progression was 12.6 months (95% confidence interval, 5.1-not reached). The median overall survival was 29.3 months. The selected phase II dose was set at a fixed dose of 35 mg of IA tirapazamine. CONCLUSIONS: IA tirapazamine with transarterial embolization was well tolerated and showed promising efficacy signals in intermediate-stage HCC, justifying pursuit of a phase II study.

Using IVIM Parameters to Differentiate Prostate Cancer and Contralateral Normal Tissue through Fusion of MRI Images with Whole-Mount Pathology Specimen Images by Control Point Registration Method.

The intravoxel incoherent motion (IVIM) model may enhance the clinical value of multiparametric magnetic resonance imaging (mpMRI) in the detection of prostate cancer (PCa). However, while past IVIM modeling studies have shown promise, they have also reported inconsistent results and limitations, underscoring the need to further enhance the accuracy of IVIM modeling for PCa detection. Therefore, this study utilized the control point registration toolbox function in MATLAB to fuse T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) MRI images with whole-mount pathology specimen images in order to eliminate potential bias in IVIM calculations. Sixteen PCa patients underwent prostate MRI scans before undergoing radical prostatectomies. The image fusion method was then applied in calculating the patients' IVIM parameters. Furthermore, MRI scans were also performed on 22 healthy young volunteers in order to evaluate the changes in IVIM parameters with aging. Among the full study cohort, the f parameter was significantly increased with age, while the D* parameter was significantly decreased. Among the PCa patients, the D and ADC parameters could differentiate PCa tissue from contralateral normal tissue, while the f and D* parameters could not. The presented image fusion method also provided improved precision when comparing regions of interest side by side. However, further studies with more standardized methods are needed to further clarify the benefits of the presented approach and the different IVIM parameters in PCa characterization.

Phase I Trial on Arterial Embolization with Hypoxia Activated Tirapazamine for Unresectable Hepatocellular Carcinoma.

BACKGROUND: Tirapazamine (TPZ) is a hypoxia activated drug that may be synergistic with transarterial embolization (TAE). The primary objective was to evaluate the safety of combining TPZ and TAE in patients with unresectable HCC and determine the optimal dose for Phase II. METHODS: This was a Phase 1 multicenter, open-label, non-randomized trial with a classic 3+3 dose escalation and an expansion cohort in patients with unresectable HCC, Child Pugh A, ECOG 0 or 1. Two initial cohorts consisted of I.V. administration of Tirapazamine followed by superselective TAE while the remaining three cohorts underwent intraarterial administration of Tirapazamine with superselective TAE. Safety and tolerability were assessed using NCI CTCAE 4.0 with clinical, imaging and laboratory examinations including pharmacokinetic (PK) analysis and an electrocardiogram 1 day pre-dose, at 1, 2, 4, 6, 10, and 24 hours post-TPZ infusion and an additional PK at 15- and 30-minutes post-TPZ. Tumor responses were evaluated using mRECIST criteria. RESULTS: Twenty-seven patients (mean [range] age of 66.4 [37-79] years) with unresectable HCC were enrolled between July 2015 and January 2018. Two patients were lost to follow-up. Mean tumor size was 6.53 cm ± 2.60 cm with a median of two lesions per patient. Dose limiting toxicity and maximum tolerated dose were not reached. The maximal TPZ dose was 10 mg/m2 I.V. and 20 mg/m2 I.A. One adverse event (AE) was reported in all patients with fatigue, decreased appetite or pain being most common. Grade 3-5 AE were hypertension and transient elevation of AST/ALT in 70.4% of patients. No serious AE were drug related. Sixty percent (95% CI=38.7-78.9) achieved complete response (CR), and 84% (95% CI=63.9-95.5) had complete and partial response per mRECIST for target lesions. DISCUSSION: TAE with TPZ was safe and tolerable with encouraging results justifying pursuit of a Phase II trial.

Liver resection for hepatocellular carcinoma in oldest old patients.

BACKGROUND: For hepatocellular carcinoma (HCC), liver resection is a classical curative modality, despite its technical complexity. The incidence of HCC in the oldest old people (aged ≥ 85 years) is rising along with the global increase in life expectancy. Currently, no report has addressed liver resection for HCC in this aged population. PATIENTS AND METHODS: We conducted a retrospective review of 1889 patients receiving curative liver resection for newly diagnosed HCC from 1992 to 2016. At the time of operation, 1858 of them were aged < 85 years (group A), and 31 were aged ≥ 85 years (group B). Another 18 oldest old patients, whose HCC was considered resectable but were not operated on due to the patient's refusal, served as the control group (group C). The clinicopathological characteristics and early and long-term outcomes were compared between groups A and B. All associated co-morbidities of the patients were well-treated before liver resection. The overall survival (OS) rates were also compared between groups B and C. RESULT: Group B had a significantly higher incidence of associated co-morbidities and hepatitis C infection. Postoperative complication rates and 90-day mortality rates after liver resection did not differ between groups A and B (p = 0.834 and p = 1.000, respectively), though group B had a longer postoperative stay (p = 0.001). In groups A and B, the 5-year disease-free survival rates were 29.7% and 22.6% (p = 0.163), respectively, and their overall survival rates were 43.5% and 35.5% (p = 0.086). The overall survival rate of group B was significantly different from group C (35.5% vs. 0%, p = 0.001). CONCLUSION: Despite a longer postoperative recovery period, liver resection for HCC in the oldest old patients may be justified if co-morbidities are well controlled.

Multidisciplinary Taiwan Consensus Recommendations for the Use of DEBDOX-TACE in Hepatocellular Carcinoma Treatment.

Transarterial chemoembolization (TACE) is the first-line treatment in patients with unresectable hepatocellular carcinoma (HCC). In recent years, there has been increasing clinical evidence that drug-eluting beads provide a combined ischemic and cytotoxic effect that may be superior to conventional TACE, with low systemic toxicity. The therapeutic value of TACE performed using the embolic microsphere DC Bead loaded with doxorubicin (drug-eluting bead doxorubicin [DEBDOX]) has been shown by several randomized controlled trials. Since Lencioni et al. [Cardiovasc Intervent Radiol 2012; 35: 980-985] published the first widely accepted technical recommendations on HCC embolization with DEBDOX-TACE in 2012, new studies have contributed to a better understanding of when and how to apply this new therapeutic modality, and they have yet to be incorporated into an updated guideline. Additionally, differences in the underlying liver pathology and practice of transcatheter embolization between Asian and Western populations have not been adequately addressed, and there remain significant variations in the TACE protocols adopted in different parts of the world. These mainly revolve around the number and type of chemotherapeutic agents used, type of embolic material, reliance on Lipiodol, and selectivity of catheter positioning. As a result of these issues, it has been difficult to interpret and compare results obtained from different centers in a systematic fashion. To address these concerns, we convened a panel of experts specializing in different aspects of HCC treatment to craft an updated set of recommendations that better reflect recent clinical experiences and are tailored to the use of DEBDOX-TACE in Taiwan. The conclusions of this expert panel are described in the following article.

Comparable Outcomes of Ultrasound versus Computed Tomography in the Guidance of Radiofrequency Ablation for Hepatocellular Carcinoma.

OBJECTIVES: To compare the efficacy and safety of ultrasound (US) and computed tomography (CT) in the guidance of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: We retrospectively analyzed consecutive treatment-naïve patients who received curative RFA for HCC from January 2008 to July 2013. Patients were divided into the US group or the CT group according to their RFA guidance instruments. Patients who were only suitable for US- or CT-guided RFA were excluded. Cumulative incidences of and hazard ratios for HCC recurrence were analyzed after adjusting for competing mortality risk. RESULTS: We recruited a total of 101 patients in the US group and 51 patients in the CT group. The baseline demographic characteristics were not significantly different in both groups. Initial response rates were similar between the two groups (US vs. CT: 89.1% vs. 92.2%, p = 0.54), and complete tumor ablation was finally achieved for all patients. However, more ablations per session were performed in US group (median 2.0 [1.0-3.0] vs. 1.0 [1.0-2.0]; p<0.01). The 1-, 2- and 3-year local tumor recurrence rates (US vs. CT: 13.0%, 20.9%, and 29.2% vs. 11.2%, 29.8% and 29.8%, respectively) and overall mortality rates (US vs. CT: 5.2%, 9.6% and 16.5% vs. 0%, 3.1% and 23.8%, respectively) were not significantly different. In multivariate analysis, tumor characteristics and underlying liver function, but not US or CT guidance, were independent prognostic factors. The complication rates were similar between the two groups (US vs. CT: 10.9% vs. 9.8%; p = 0.71), and there was no procedure-related mortality. CONCLUSIONS: With comparable major outcomes, either US or CT can be used in the guidance of RFA in experience hands.

Temporary prophylactic intravascular balloon occlusion of the common iliac arteries before cesarean hysterectomy for controlling operative blood loss in abnormal placentation.

OBJECTIVES: The purpose of this study was to investigate the efficacy and safety of temporary prophylactic intravascular balloon occlusion of the common iliac arteries (CIA) before planned cesarean hysterectomy for controlling operative blood loss in abnormal placentation. MATERIALS AND METHODS: A retrospective study of 13 pregnant women at risk for placenta accreta identified using sequential obstetric ultrasonography and magnetic resonance imaging from January 2007 to December 2009 was performed. Temporary prophylactic intravascular balloon catheterization of the bilateral CIA before cesarean hysterectomy was performed by interventional radiologists. The maximum duration of occlusion time of CIA must not exceed 60 minutes. The primary outcome for this study included estimated blood loss and secondary outcomes included the development of thromboembolism, disseminated intravascular coagulation and surgical complications. RESULTS: Among these 13 patients, the mean age of the patients was 32.8 ± 0.7 years (range 29-37 years). The mean gestational age at cesarean hysterectomy was 32.2 ± 0.9 weeks (range 28-36 weeks), and the mean intraoperative blood loss was 1902.3 ± 578.8 mL (range 500-8000 mL). Operative bleeding was controlled by conservative treatment without additional surgery in two cases. Importantly, two patients (15.8%) had severe complications possibly related to the interventional procedure. One patient was noted to have a popliteal artery thrombosis. A second patient had an external iliac artery thrombosis with 80-90% occlusion. Both patients required antithrombotic treatment without sequelae. CONCLUSION: With limited experience in this small series, we observed a statistically significant reduction in operative blood loss after the use of temporary prophylactic balloon occlusion of the CIA technique compared with historical controls of similar demographic characteristics previously published (1902.3 ± 578.8 mL, range 500-8000 mL vs. 4445.7 ± 996.48 mL, range 1040-15,000 mL, p = 0.0402). Additionally, two patients had arterial thrombosis. These preliminary findings are based on a small number of patients, and therefore further investigation is needed to determine the effectiveness and safety of this new technique.

Insulinoma in a young female patient with systemic lupus erythematosus: a case report.

OBJECTIVE: Fasting hypoglycemia may occur in subjects with systemic lupus erythematosus (SLE) when accompanied with insulin-binding antibodies or insulin-receptor antibodies. However, insulinoma has not been reported in SLE subjects with hypoglycemia. METHODS: We present a case report and review the relevant literature. RESULTS: A 26-year-old female with underlying SLE experienced several episodes of neuropsychiatric symptoms in a fasting state. The steroid dosage was titrated up, but in vain. Timely imaging studies showed a pancreatic tumor, and insulinoma was proven by pathology. Hypoglycemia did not recur after surgery. CONCLUSION: Physicians should distinguish insulinoma from autoimmunity-mediated hypoglycemia in SLE patients with fasting hypoglycemia.

Thick calcification from a GIST of the stomach penetrating into pericolic soft tissue--report of a case.

Thick calcification is a rare presentation of gastrointestinal stromal tumor (GIST). Penetration into gastric mucosa and pericolic soft tissue has never been reported. We report a case of gastric GIST with cystic degeneration and thick calcification in an 81-year old female, who presented with hematemesis and severe abdominal pain. Thick calcification of this tumor penetrating into pericolic soft tissue was noted and successfully treated by distal gastrectomy and partial colectomy. For gastrointestinal tumors with thick calcification, even with benign behavior, surgical intervention should be considered for both oncological considerations and prevention of catastrophes like perforation or penetration into surrounding soft tissue.

Uterine necrosis associated with acute suppurative myometritis after angiographic selective embolization for refractory postpartum hemorrhage.

We report a case of a woman in whom uterine arterial embolization was performed using absorbable gelfoam particles for control of refractory postpartum hemorrhage. Ten days after delivery, the woman experienced high fever and low abdominal pain. Histologic findings after hysterectomy were consistent with uterine necrosis and acute suppurative myometritis.

Gastrointestinal stromal tumors: computed tomographic features and prediction of malignant risk from computed tomographic imaging.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are specific, generally Kit (CD117)-positive, mesenchymal tumors of the gastrointestinal tract encompassing a majority of tumors previously considered gastrointestinal smooth muscle tumors. Our aim was to characterize the computed tomographic findings and predict malignant risk from computed tomography for the evaluation of GISTs. METHODS: The computed tomographic images of 39 patients with pathologically and immunohistochemically proven GISTs were reviewed by 2 radiologists, and the final interpretations were reached by consensus. Images were assessed for the size, contour, growth pattern, boundary, degree of enhancement, and necrosis of the tumors. The presence of calcification within the lesions, abdominal lymphadenopathy, ascites, and bowel obstruction were also recorded. Categorical variables were compared using Fishers exact test. Univariate and multivariate logistic regression analyses were used for selection of significant predictors of high-risk malignancy. In addition, the relationships between computed tomographic features and tumor size were assessed by means of nonparametric univariate analysis with the MannWhitney U test and KruskalWallis test. RESULTS: Both old age and larger tumor size (>or= 5 cm) were statistically significant in the univariate logistic analysis for high-risk malignant tumors (p < 0.25). However, in multivariate logistic regression, only larger tumor size (>or= 5 cm) was found to have final statistical significance for high-risk malignant GISTs (p < 0.05). In addition, more exophytic growth pattern (p < 0.01), more lobulated appearance (p < 0.01), good enhancement (p < 0.05),and more necrosis (p < 0.01) of masses were more often observed in larger GISTs than small ones on computed tomography. CONCLUSION: Larger tumor size (>or= 5 cm) was found to have a predictive value with respect to high-risk malignant GISTs.

Primary small cell carcinoma of the pancreas with an unusual sonographic appearance.

We present a case of primary pancreatic small cell carcinoma with an unusual sonographic feature. A 75-year-old woman presented with poor appetite and weight loss. Abdominal sonographic examination revealed a diffusely enlarged pancreas with relative increased echogenicity and smooth contour. CT also confirmed the diffuse infiltrative pattern of the tumor. The diagnosis was confirmed via sonographically guided biopsy. The tumor was composed of small cells with hyperchromatic nuclei and scanty cytoplasm infiltrating the pancreatic tissue, consistent with small cell carcinoma of the pancreas. Primary pancreatic small cell carcinoma rarely presents as the diffuse infiltrating type. These unusual sonographic features must be differentiated from other pancreatic tumors presenting as diffuse pancreatic enlargement.

A rare hernia of intra-abdominal fat in the thorax under an intact diaphragm: multidetector computed tomography.

Neither abdominal wall hernia nor diaphragmatic hernia is an unusual disease. But some may have difficulty diagnosing the presence of intra-abdominal fat in the thorax under an intact diaphragm. We report a case with an external compression of the right lower lung from intra-abdominal fat owing to a hernia through the right lateral abdominal wall and secondary through the ninth intercostal space of the chest wall to the right lower thorax without traumatic history. Multiple images, including multidetector row computed tomography, are reviewed.

Experience with conservative strategy of uterine artery embolization in the treatment of placenta percreta in the first trimester of pregnancy.

OBJECTIVE: There is little prospective experience in the conservative treatment of placenta percreta during the first trimester in order to preserve uterine fertility. We describe herein our experience with uterine artery embolization (UAE) in the management of placenta percreta at 9 weeks of gestation. CASE REPORT: A 36-year-old woman, gravida 3, para 1, was referred for ultrasonographic evaluation because of suspected molar pregnancy due to persistent vaginal spotting at 9 weeks of gestation. A Grade 3+ lacunar flow pattern with multiple bizarre and large irregular sonolucent spaces were observed. Color Doppler imaging revealed extensive turbulent lacunar blood flow perfusing throughout the whole surrounding uteroplacental tissues and fetus. The patient was informed of the situation and she had a strong desire to avoid surgery. Conservative management with bilateral UAE was performed using polyvinyl alcohol particles to promote involution and shedding of the abnormally adherent placenta. However, an unsatisfactory vessel-occluding effect caused by extensive collateral supply was still detected after repeated UAE. We, therefore, performed hysterectomy, and the patient had an uneventful postoperative course. CONCLUSION: The efficacy and complications of UAE as a therapeutic modality for the conservative management of invasive placentation in the first trimester of pregnancy are not clear, as this is the first report of its kind. However, although UAE had failed in this case, it may still be a useful procedure as a prophylactic measure before surgical intervention, and hysterectomy can also be performed for better control of operative hemorrhage.

Percutaneous placement of metallic stents in the management of malignant biliary obstruction.

BACKGROUND AND PURPOSE: The placement of metallic stents is now a well-established method in the management of malignant biliary obstruction. This study evaluated the long-term clinical efficacy of percutaneous transhepatic insertion of metallic stents in the management of malignant biliary obstruction. METHODS: From January 1999 to December 2002, 102 consecutive patients with malignant biliary obstruction were treated with percutaneous transhepatic placement of metallic stents at a medical center in Taipei. The level of obstruction was at the hepatic hilum in 44 patients, and common bile duct (CBD) in 58 patients. Memotherm stents were used in 78 patients and Wallstents in 38. Among the 44 patients with hilar obstruction, 30 received a single stent and 14 received bilateral stents. Among the 58 patients with CBD obstruction, the stents were placed across the ampulla of Vater in 27. Patient survival rates and stent patency rates were compared using the Kaplan-Meier method. RESULTS: Placement of stents was successful in all patients. The mean (range) serum bilirubin level before, 1 week after, and 1 month after stent insertion was 15.1 mg/dL (4.2-32.4 mg/dL), 7.8 mg/dL (0.5-19.4 mg/dL), and 1.8 mg/dL (0.2-8.2 mg/dL), respectively. The mean survival in all patients was 66.0 weeks (1-130 weeks) and the mean stent patency period (MSPP) in all patients was 59.9 weeks (1-130 weeks). The MSPP was 71.4 versus 49.9 weeks in hilar type versus CBD type patients (p = 0.047). The MSPP was 53.9 versus 73.0 weeks in patients who received Memotherm stents versus Wallstents (p = 0.115). In the hilar obstruction group, the MSPP was 82.1 versus 58.0 weeks in patients receiving bilateral versus a single stent (p = 0.039). In the CBD obstruction group, the MSPP was 46.3 versus 45.5 weeks in stents placed across versus not placed across the ampulla of Vater (p = 0.338). CONCLUSIONS: The efficacy and patency period of percutaneous transhepatic insertion of metallic stents in the management of malignant biliary obstruction is satisfactory in the relief of obstructive jaundice. Both types of metallic stents performed well in relieving malignant biliary obstruction. Bilateral stenting was more effective than single stenting in treating patients with hilar obstruction. In patients with CBD obstruction, no significant difference in the stent patency period was found between stents placed across or not across the ampulla of Vater.

Percutaneous ultrasound-guided radiofrequency ablation of intrahepatic cholangiocarcinoma.

This study evaluated the clinical applications, treatment effects, and complications of percutaneous ultrasound (US)-guided radiofrequency ablation (RFA) of intrahepatic cholangiocarcinoma. Ten patients (6 men and 4 women) with histologically proven cholangiocarcinoma underwent US-guided percutaneous RFA. Tumor diameters ranged from 1.9 to 6.8 cm. There were 12 sessions of RFA for 10 solitary cholangiocarcinomas. Eight patients were treated at a single session and two patients had two treatment sessions. The efficacy of RFA was evaluated using contrast-enhanced dynamic computed tomography 1 month after treatment and then every 3 months. Complete necrosis was defined as lack of contrast enhancement of the treated region. There was complete necrosis in eight tumors. In two patients with large tumors (4.7 and 6.8 cm in diameter), enhancement of residual tissue was observed after RFA treatment, indicating residual tumor. Complete necrosis was seen in all five tumors (100%) with diameters of 3.0 cm or less, two of three tumors (67%) with diameters of 3.1-5.0 cm, and one of two tumors (50%) with diameters of more than 5.0 cm. A large biloma was found in one patient after treatment. No serious complications occurred in the other nine patients. In conclusion, percutaneous RFA is effective and successful in the treatment of intrahepatic cholangiocarcinoma of 3 cm or less and satisfactory for tumors of 3-5 cm. The rate of serious complications after RFA is low. Further follow-up is necessary to determine long-term efficacy.

Development of a safety index of transarterial chemoembolization for hepatocellular carcinoma to prevent acute liver damage.

BACKGROUND: Transarterial chemoembolization (TACE) is the most effective palliative treatment for hepatocellular carcinoma (HCC), but may cause acute liver damage. MATERIALS AND METHODS: One hundred and ninteen patients with unresectable HCCs, undergoing TACE, were studied prospectively. A safety index to prevent acute liver damage was developed by using logistic regression. RESULTS: Acute liver damage by TACE was not related to the gender or age, but was mostly correlated to Child's classification (beta = 1.89, OR = 6.6, CI: 2.07, 21.01) and the amount of Lipiodol (beta = 0.09, OR = 1.09, CI: 1.02, 1.16) used for the TACE. CONCLUSION: In treatment of a Child's B/C patient by TACE, no more than 20 ml Lipiodol should be used.

Percutaneous radiofrequency ablation of renal cell carcinoma.

BACKGROUND: Preliminary data regarding the use of percutaneous radiofrequency ablation (RFA) for the treatment of renal cell carcinoma (RCC) are encouraging, and show the technique to be associated with minimal morbidity. Thus, the current study was designed to evaluate the clinical applications, treatment efficacy, and complications of percutaneous RFA in RCC. METHODS: From February 2003 to February 2004, 12 consecutive patients with histopathologically proven RCC underwent imaging-guided percutaneous RFA. The mean age of the patients (8 men and 4 women) was 76 years (range, 56-87 years), and mean tumor diameter was 3.7 cm (range, 2.2-8.0 cm). The efficacy of RFA was evaluated with contrast-enhanced, dynamic computed tomography (CT) performed 1 month after treatment, and then every 3 months. A Radionics device with an internally cooled electrode was used in 7 patients, and a radiofrequency interstitial tissue ablation (RITA) device with an expandable needle electrode was used in 5. Complete necrosis was defined as a lack of contrast enhancement in the treated region on follow-up CT studies. RESULTS: Overall, 16 sessions of RFA were performed for 12 solitary renal tumors in 12 patients: 8 patients underwent a single RFA session, whereas 4 had 2 sessions. Dynamic CT after RFA showed complete necrosis in 9 of 12 tumors. In 3 patients with tumors of 4.5-8.0 cm in diameter, enhancement of residual tissue was observed after RFA treatment, thus indicating residual tumor. Complete tumor necrosis was seen in all 5 tumors (100%) of diameter < or = 3.0 cm; 3 of 4 tumors (75%) of diameter 3.1-5.0 cm; and 1 of 3 tumors (33%) of diameter > 5.0 cm. A big subcapsular hematoma, which was found in 1 patient after RFA, resolved completely within 10 months without treatment; no serious complications occurred in the other 11 patients. CONCLUSION: Percutaneous RFA is effective in the treatment of RCC. It is most successful for tumors not larger than 3 cm in diameter, and has a satisfactory success rate in tumors of 3-5 cm in diameter. The rate of serious complications of RFA is low. Further studies are necessary to determine the long-term efficacy of RFA in RCC.