Masashi Fujimori

Radiofrequency Ablation versus Radical Nephrectomy: Clinical Outcomes for Stage T1b Renal Cell Carcinoma

PURPOSE To compare clinical outcomes of radiofrequency (RF) ablation retrospectively with those after radical nephrectomy in patients with stage T1b renal cell carcinoma (RCC). MATERIALS AND METHODS This retrospective study was approved by the institutional review board, and the requirement to obtain written informed consent was waived. From June 2002 to March 2012, 60 patients (mean age, 65.2 years; age range, 39-86 years) with a single RCC measuring 4.1-7.0 cm (stage T1b) underwent RF ablation (n = 21) or radical nephrectomy (n = 39). Selective renal artery embolization was performed before RF ablation in eight patients. The overall, RCC-related, and disease-free survival rates, the percentage decrease in the glomerular filtration rate (GFR), and safety were compared by using the log-rank (survival), paired and Student t (GFR), and Fisher exact (safety) tests. RESULTS The overall survival rate was significantly lower in the RF ablation group than in the radical nephrectomy group (48% vs 97% at 10 years, respectively; 95% confidence interval [CI]: 12.4%, 76.7% vs 78.2%, 99.5%; P < .009). The RCC-related survival rate (94% [95% CI: 62.6%, 99.1%] with RF ablation vs 100% with radical nephrectomy at 10 years) and the disease-free survival rate (88% [95% CI: 59.2%, 96.9%] with RF ablation vs 84% [95% CI: 60.6%, 94.3%] with radical nephrectomy at 10 years, P = .99) were comparable between the two groups. No treatment-related deaths occurred. Although major complication rates were similar between the two patient groups (8.0% [two of 25 patients] vs 5.1% [two of 39 patients], P = .61), the percentage decrease in the GFR was significantly lower in the RF ablation group than in the radical nephrectomy group at the last follow-up (12.5% ± 23.4 vs 32.3% ± 20.8, respectively; P < .003). CONCLUSION RF ablation is a safe procedure for patients at substantial surgical risk for radical nephrectomy, providing comparable RCC-related and disease-free survival and preserving renal function.

Renal Cell Carcinoma: Radiofrequency Ablation with a Multiple-Electrode Switching System—A Phase II Clinical Study

PURPOSE To prospectively evaluate the safety and effectiveness of radiofrequency ablation with a multiple-electrode switching system for the treatment of renal cell carcinoma (RCC). MATERIALS AND METHODS From November 2009 to December 2010, 33 patients (mean age, 70.7 years; range, 44-86 years) with histologically proved RCCs--including 24 men (mean age, 69.5 years [range, 44-86 years]) and nine women (mean age, 74.1 years [range, 64-83 years])--were enrolled in this phase II study. The institutional review board approved the study after patients provided written informed consent. The mean maximum tumor diameter was 2.9 cm ± 1.0 (standard deviation) (range, 1.5-5.0 cm). Radiofrequency ablation was conducted with a multiple-electrode switching system. The primary endpoint was evaluated with the Common Terminology Criteria for Adverse Events. Secondary endpoints were changes in renal function, technique effectiveness, local tumor progression, and survival. Changes in renal function were evaluated by using the Mann-Whitney U test. RESULTS No severe adverse events occurred, but three of 33 patients (9%) had grade 2 adverse events. Although the mean glomerular filtration rate at 1 year after radiofrequency ablation was similar to the baseline value in 26 patients with bilateral kidneys (P = .14), it was decreased significantly in six patients with a single kidney (P = .03). Tumor enhancement disappeared after a single radiofrequency session in 31 patients and after two radiofrequency sessions in the other two patients (rates of primary and secondary technique effectiveness, 94% [31 of 33] and 100% [33 of 33], respectively). No local tumor progression was found during the mean follow-up of 20.0 months (range, 11.6-27.6 months). The respective 1-year overall and RCC-related survival rates were 97% (95% confidence interval: 91%, 100%) and 100%. CONCLUSION Radiofrequency ablation with a multiple-electrode switching system is safe and effective for treatment of RCCs. However, further study is warranted to determine whether this technology is superior to other previously described methods.

Unresectable Adrenal Metastases: Clinical Outcomes of Radiofrequency Ablation

PURPOSE To retrospectively evaluate the clinical outcomes of radiofrequency (RF) ablation for the treatment of unresectable adrenal metastasis. MATERIALS AND METHODS The institutional review board approved this retrospective study, and informed consent to perform adrenal RF ablation was obtained from all patients. From February 2005 through May 2014, 35 patients (25 men and 10 women; mean age, 64.7 years ± 9.6; age range, 39-82 years) underwent RF ablation to treat 41 metastatic adrenal tumors from lung cancer (n = 15), renal cell carcinoma (n = 9), colorectal cancer (n = 5), hepatocellular carcinoma (n = 4), and other tumors (n = 2). Tumors ranged in size from 1.2 to 8.2 cm (mean, 3.3 cm ± 1.6). The diagnosis was established mainly on the basis of radiologic findings. Adrenal arterial embolization was combined with RF ablation in 12 of the 35 patients (34%). Technical success, safety, local tumor progression, and survival were evaluated. The Kaplan-Meier method and Cox proportional hazard model were used to evaluate prognostic factors. RESULTS There were 48 completed sessions with planned procedures and treatment protocols with no mortality and a major complication rate of 8.3% (four of 48 sessions). Tumor enhancement disappeared after initial adrenal RF ablation in 33 of the 35 patients (94%). Local tumor progression developed in eight of the 35 patients (23%); two patients received repeated RF ablation, resulting in adrenal tumor control in 27 of the 35 patients (77%) at the last follow-up (mean, 30.1 months ± 27.5; range 1.2-96.8 months). The 1-, 3-, and 5-year overall survival rates were 75% (95% confidence interval [CI], 61%, 90%), 34% (95% CI: 17%, 52%), and 30% (95% CI: 13%, 48%), respectively, with a median survival time of 26.0 months. Existence of extra-adrenal tumors (P = .005) and age of 65 years or older (P = .04) were significant indicators of a poor prognosis. CONCLUSION Adrenal RF ablation is a feasible and useful method for controlling adrenal metastases and offers patients opportunities for improved survival.

Survival with up to 10-year Follow-up after Combination Therapy of Chemoembolization and Radiofrequency Ablation for the Treatment of Hepatocellular Carcinoma: Single-center Experience

PURPOSE To report 10-year outcomes of treating hepatocellular carcinomas (HCCs) by combination therapy of chemoembolization and radiofrequency (RF) ablation. MATERIALS AND METHODS Combination therapy was administered in 277 patients with 382 treatment-naïve HCCs. Therapeutic effects, safety, survival rate, and prognostic factors were evaluated. RESULTS Tumor enhancement disappeared after 466 RF sessions in all tumors, resulting in a complete response rate of 100% (277 of 277) based on modified Response Evaluation Criteria In Solid Tumors. Local tumor progression developed in 15 patients (5.4%; 15 of 277) during the mean follow-up of 44.9 months±29.1 (range, 6.0-134.4 mo). Overall and recurrence-free survival rates were 56.3% (95% confidence interval [CI], 52.5%-60.2%) and 22.5% (95% CI, 19.3%-25.6%) at 5 years and 23.5% (95% CI, 17.7%-29.2%) and 9.3% (95% CI, 6.3%-12.4%) at 10 years. The Child-Pugh class was the only significant prognostic factor detected in both the univariate (P<.001) and the multivariate analyses (hazard ratio, 3.8; 95% CI, 2.5-5.6; P<.001). The 5-year and 10-year overall survival rates were 66.4% (95% CI, 62.0%-70.8%) and 30.6% (95% CI, 23.3%-37.9%) in 210 Child-Pugh class A patients. In addition to the Child-Pugh class, the maximum tumor diameter (≤3 cm vs>3 cm) and the tumor number (single vs multiple) were significant independent factors affecting recurrence-free survival. No death was related to the combination therapy. The major complication rate was 3.2% (15 of 466). CONCLUSIONS RF ablation combined with chemoembolization is a safe and useful therapeutic option for treating HCCs. Prognostic factors detected in this study help to stratify patients who benefit from this combination therapy.

Radiofrequency Ablation for Liver Metastasis from Gastrointestinal Stromal Tumor

PURPOSE To evaluate the feasibility, safety, and clinical outcomes of radiofrequency (RF) ablation for the treatment of liver metastases from gastrointestinal stromal tumor (GIST). MATERIALS AND METHODS Seven consecutive patients with 21 GIST liver metastases received RF ablation under computed tomographic (CT) fluoroscopic guidance. Liver metastases were solitary in two patients and multiple in five patients, with a mean maximum tumor diameter of 2.2 cm±1.1 (range, 1.2-4.2 cm). In addition to feasibility and safety, local tumor progression and overall and GIST-related survival associated with RF ablation were assessed. RESULTS All liver metastases were treated in 12 RF sessions, after which contrast-enhanced CT showed disappearance of tumor enhancement. No RF procedure-related complications occurred. Local tumor progression developed in one tumor (4.8%) during the mean follow-up period of 30.6 months±27.5 (range, 5.9-76.4 mo). New liver metastasis in untreated liver and lung metastasis developed in one patient each. One patient died of subarachnoid hemorrhage 5.9 months after RF ablation, but no GIST-related deaths occurred. The respective overall and GIST-related survival rates were 85.7% (95% confidence interval, 33.6%-97.8%) and 100% at 1, 3, and 5 years. CONCLUSIONS RF ablation is a feasible, safe, and useful therapeutic option for the treatment for GIST liver metastases.

Transarterial chemoembolization for hepatitis B virus-associated hepatocellular carcinoma: improved survival after concomitant treatment with nucleoside analogues.

PURPOSE To determine whether nucleoside analogue therapy is associated with improved survival in patients with hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) who are treated solely with transarterial chemoembolization. MATERIALS AND METHODS A retrospective chart review of patients diagnosed with HBV-associated HCC was performed to identify patients treated solely with chemoembolization. Relevant demographic and clinical data were extracted and recorded. The influence of therapy with nucleoside analogues (lamivudine, adefovir dipivoxil, or entecavir) was determined by estimating the survival function using the Kaplan-Meier product-limit method. RESULTS The inclusion criteria for chemoembolization were met by 81 patients (67 men and 14 women, mean age 60.6 years ± 9.2); 21 (25.9%) of these patients had been treated with nucleoside analogues. The number of chemoembolization treatments was significantly greater in the patients who were treated with nucleoside analogues (3.43 ± 2.32) than in the patients who did not receive nucleoside analogues (1.82 ± 0.95; P = .0022). The 1-year, 3-year, and 5-year survival rates were 89.5%, 66.8%, and 40.5% in the patients treated with nucleoside analogues and 72.6%, 27.5%, and 14.3% in the patients not treated with nucleoside analogues. The survival rate was significantly higher in the patients who received nucleoside analogues (P = .0051). Nucleoside analogue intake was an independent factor that was associated with increased survival (P = .0063). CONCLUSIONS Administration of nucleoside analogues was associated with longer survival in patients with HBV-associated HCC who were treated with transarterial chemoembolization.

CT-Guided Percutaneous Cryoablation in Renal Cell Carcinoma: Factors Affecting Local Tumor Control

PURPOSE To retrospectively evaluate factors affecting local tumor control in cryoablation of renal cell carcinomas (RCCs). MATERIALS AND METHODS This study examined 61 patients (43 men, 18 women) with a mean age of 69.1 years ± 10.8 (range 38-87 y) who underwent computed tomography (CT)-guided percutaneous cryoablation for a single RCC and were followed for 6 months or longer. Maximum tumor diameter was 0.8-4.8 cm (mean ± standard deviation, 2.4 ± 0.9 cm). Factors affecting local tumor control were evaluated. Deep tumor location was defined as the center side of the body perpendicular to the kidney midline. RESULTS Median follow-up was 12.7 months. Residual unablated tumors and local tumor progression were observed after initial cryoablation in 4 patients each (13%, 8 of 61). All uncontrolled tumors were located in the deep side of the kidney (100%, 8 of 8), and were covered by an ice-ball margin of 5 mm or less. Deep tumor location (P = .005) and ice-ball margin (P = .002) were detected as significant factors affecting local tumor control on univariate analysis, and ice-ball margin remained significant in a stepwise logistic regression model (P = .006; odds ratio, 0.57; 95% confidence interval, 0.38-0.83). Complete tumor control rates were 42.9% (3 of 7), 92.6% (50 of 54), and 100% (20 of 20) with ice-ball margins of less than 3 mm, 3 mm or larger, and 6 mm or larger, respectively. CONCLUSIONS Deep tumor location and ice-ball margins less than 6 mm were associated with incomplete local control following CT-guided percutaneous cryoablation for RCC.

Combination Therapy of Chemoembolization and Radiofrequency Ablation for the Treatment of Hepatocellular Carcinoma in the Caudate Lobe

PURPOSE To evaluate the clinical utility of radiofrequency (RF) ablation combined with chemoembolization in treatment of hepatocellular carcinoma (HCC) located in the caudate lobe. MATERIALS AND METHODS Between September 2000 and October 2011, 20 consecutive patients with single HCC measuring≤5 cm were treated with combination therapy of chemoembolization and RF ablation. Technical success was defined as completion of a planned electrode placement and ablation protocol. The effectiveness of the technique was defined as disappearance of tumor enhancement with an ablative margin of≥5 mm. Technical success, technique effectiveness, local tumor progression, overall and recurrence-free survival, and complications were evaluated. RESULTS RF electrodes were placed in planned sites of each tumor, and ablation was complete in all patients (technical success rate 100%). Tumor enhancement disappeared with sufficient ablative margins after 20 RF sessions in all patients (technique effectiveness rate 100%). Major and minor complication rates were 10.0% and 15.0%. Local tumor progression was found in 2 of 20 patients (10.0%) with local tumor progression rates of 6.3% at 1 year and 13.5% at 3 years and 5 years. Six patients died during the follow-up period (mean, 40.0 months; range, 2.0-110.5 months). Overall and recurrence-free survival rates were 94.4% and 70.8% at 1 year, 86.6% and 36.9% at 3 years, and 67.5% and 45.5% at 5 years. CONCLUSIONS RF ablation combined with chemoembolization is a safe and useful therapeutic option to treat HCCs located in the caudate lobe.

Radiofrequency Ablation Using a Multiple-Electrode Switching System for Lung Tumors with 2.0–5.0-cm Maximum Diameter: Phase II Clinical Study

PURPOSE To prospectively evaluate the safety and effectiveness of radiofrequency ablation (RFA) by using a multiple-electrode switching system to treat 2.0-5.0-cm lung tumors. MATERIALS AND METHODS The institutional review board approved this prospective phase II study. Written informed consent was obtained from all patients. Between September 2009 and July 2011, RFA using two or three radiofrequency (RF) electrodes and a multiple-electrode switching system was performed for malignant lung tumors with a maximum tumor diameter of 2.0-5.0 cm in nonsurgical candidates. The primary endpoint was safety, as evaluated using the Common Terminology Criteria for Adverse Events. Patients were observed for at least 1 year. Local tumor progression and overall survival were analyzed with the Kaplan-Meier method. RESULTS Thirty-three patients (26 men, seven women; mean age, 70.5 years ± 10.0; age range, 46-87 years) with 35 lung tumors with a mean maximum diameter of 3.0 cm ± 0.7 (standard deviation; range, 2.0-4.4 cm) underwent treatment in 35 sessions. No procedure-related death or grade 4 adverse events (AEs) occurred. Grade 3 AEs occurred in four patients (12%), with pleural effusion requiring chest tube placement in two patients, pneumothorax requiring pleural adhesion in one patient, and pulmonary hemorrhage requiring pulmonary artery coil embolization in one patient. Grade 2 AEs were detected in 13 patients (39%). The 1-year local tumor progression and overall survival rates were 12.7% (95% confidence interval [CI]: 1.0, 25.5) and 81.2% (95% CI: 67.6, 94.8). CONCLUSION RFA with a multiple-electrode switching system may be a safe therapeutic option with which to treat 2.0-5.0-cm lung cancer tumors.

Safety and Clinical Outcomes of Percutaneous Radiofrequency Ablation for Intermediate and Large Bone Tumors Using a Multiple-Electrode Switching System: A Phase II Clinical Study

PURPOSE To evaluate the safety and clinical outcomes of radiofrequency (RF) ablation using a multiple-electrode switching system in patients with bone tumors > 3 cm. MATERIALS AND METHODS This prospective study enrolled 20 subjects (15 men, 5 women; mean age 70.0 y ± 7.4 [SD]; range, 60-80 y) with malignant unresectable bone tumors. The maximum mean tumor diameter was 5.5 cm ± 2.0 (range, 3.1-10.0 cm). Two to three RF electrodes were placed into each bone tumor. Real-time CT fluoroscopic guidance was used with a multiple-electrode switching system. The primary endpoint was safety, as evaluated by Common Terminology Criteria for Adverse Events, until 12 months after bone RF ablation. As secondary endpoints, pain relief was evaluated by visual analog scale (VAS) scores before and 1 week after RF ablation; tumor response, by contrast-enhanced magnetic resonance imaging studies until 4 weeks after bone RF ablation; and survival, by Kaplan-Meier method. RESULTS No adverse event was found in 19 of 20 patients (95%). Grade 2 fever occurred in 1 patient (5%; 1/20). VAS scores decreased by ≥ 2 in 11 of 13 patients (84.6%) who had painful bone tumors. Tumor response (complete or partial response) was achieved in 16 of 18 patients (88.9%) who underwent follow-up imaging studies. The 1-year overall survival rate was 60.9%, and the median survival time was 14.1 months. CONCLUSIONS Bone RF ablation using this system is safe and achieves local tumor control and pain relief in patients with large bone tumors.