Junji Uraki

Complications After 1000 Lung Radiofrequency Ablation Sessions in 420 Patients: A Single Center’s Experiences

OBJECTIVE This study retrospectively evaluates complications after lung radiofrequency ablation (RFA). MATERIALS AND METHODS Complications were assessed for each RFA session in 420 consecutive patients with 1403 lung tumors who underwent 1000 RFA sessions with a cool-tip RFA system. A major complication was defined as a grade 3 or 4 adverse event. Risk factors affecting frequent major complications that occurred with an incidence of 1% or more were detected using multivariate analysis. RESULTS Four deaths (0.4% [4/1000]) related to RFA procedures occurred. Three patients died of interstitial pneumonia. The other patient died of hemothorax. The major complication rate was 9.8% (98/1000). Frequent major complications were aseptic pleuritis (2.3% [23/1000]), pneumonia (1.8% [18/1000]), lung abscess (1.6% [16/1000]), bleeding requiring blood transfusion (1.6% [16/1000]), pneumothorax requiring pleural sclerosis (1.6% [16/1000]), followed by bronchopleural fistula (0.4% [4/1000]), brachial nerve injury (0.3% [3/1000]), tumor seeding (0.1% [1/1000]), and diaphragm injury (0.1% [1/1000]). Puncture number (p < 0.02) and previous systemic chemotherapy (p < 0.05) were significant risk factors for aseptic pleuritis. Previous external beam radiotherapy (p < 0.001) and age (p < 0.02) were significant risk factors for pneumonia, as were emphysema (p < 0.02) for lung abscess, and serum platelet count (p < 0.002) and tumor size (p < 0.02) for bleeding. Emphysema (p < 0.02) was a significant risk factor for pneumothorax requiring pleural sclerosis. CONCLUSION Lung RFA is a relatively safe procedure, but it can be fatal. Risk factors found in this study will help to stratify high-risk patients.

Midterm results of radiofrequency ablation versus nephrectomy for T1a renal cell carcinoma.

PurposeThe aim of this study was to retrospectively evaluate midterm results of renal radiofrequency (RF) ablation compared to the results after nephrectomy in patients with T1a renal cell carcinoma (RCC).Materials and methodsA total of 115 patients with a single RCC measuring ≤4 cm (T1a) were included; 51 patients underwent RF ablation, 54 patients radical nephrectomy, and 10 patients partial nephrectomy. The survival and the percent decreases in glomerular filtration rate (GFR) were compared among the three treatments.ResultsAlthough overall survival after RF ablation (75.0% at 5 years) was lower than those after radical and partial nephrectomy, the RCC-related survival (100% at 5 years) was comparable to those following radical nephrectomy (100% at 5 years) and partial nephrectomy (100% at 3 years). The disease-free survival (DFS) after RF ablation (98.0% at 5 years) was also comparable to those after radical nephrectomy (95.0% at 5 years) (P = 0.72) and partial nephrectomy (75.0% at 3 years) (P = 0.13). The percent decrease in the GFR at last follow-up in the RF ablation group (median 7.9%) was significantly lower than that in the radical nephrectomy group (median 29.0%) (P < 0.001) and comparable to that in the partial nephrectomy group (median 11.5%) (P = 0.73).ConclusionRF ablation provides RCC-related and DFS comparable to that found after nephrectomy with little loss of renal function.

Radiofrequency Ablation Combined with Chemoembolization for the Treatment of Hepatocellular Carcinomas Larger than 5 cm

PURPOSE To evaluate survival, recurrence-free survival, technical success, technique effectiveness, and safety of radiofrequency (RF) ablation combined with chemoembolization in patients with hepatocellular carcinomas (HCCs) larger than 5 cm. MATERIALS AND METHODS Patients with Child-Pugh class A or B cirrhosis and three or fewer HCCs with a maximum tumor diameter of 5.1-10 cm were included. Twenty patients with 32 HCCs were included. There were 16 men and four women with mean age of 69 years +/- 7.4 (range, 46-79 years).The maximum mean tumor diameter was 6.2 cm (range, 5.1-9.5 cm). RF ablation was performed under computed tomographic (CT) fluoroscopic guidance 1-2 weeks after chemoembolization. The primary endpoint of this study was survival. RESULTS RF electrodes were placed in the planned sites, and RF ablation was completed with a planned protocol (technical success rate, 100%). Tumor enhancement was eradicated in all patients after 32 RF sessions. The primary and secondary technique effectiveness rates were 40% and 100%, respectively. There were two major complications in the 32 RF sessions (6%)--hepatic abscess and diaphragm perforation. Local tumor progression developed in five of the 20 patients (25%) during the mean follow-up of 30 months. The overall and recurrence-free survival rates were, respectively, 100% and 74% at 1 year, 62% and 28% at 3 years, and 41% and 14% at 5 years. The serum bilirubin level of 1.0 mg/dL (17.1 micromol/L) or less was a significantly better prognostic factor in the univariate analysis. CONCLUSIONS This combination therapy may enhance survival in patients with HCCs larger than 5 cm.

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.

Transcatheter hepatic arterial chemoembolization for hepatocellular carcinoma invading the portal veins: therapeutic effects and prognostic factors

PURPOSE This retrospective study was undertaken to evaluate the therapeutic effects of transcatheter hepatic arterial chemoembolization on hepatocellular carcinoma (HCC) invading the portal veins and to identify prognostic factors. MATERIALS AND METHODS Sixty-one patients underwent chemoembolization. The HCC had invaded the main portal vein in 23 patients, a first-order branch in 25 patients and a second-order branch in 13 patients. The hepatic arteries feeding the tumors were embolized with gelatin sponge after a mixture of iodized oil and anticancer drugs was injected via these vessels. Tumor response was evaluated by measuring tumor sizes on CT images. A reduction in maximum diameter of 25% or more was considered to indicate response to chemoembolization. Significant prognostic factors were identified by univariate and multivariate analyses. RESULTS Tumor size was reduced by 25% or more in 26 patients (43%). The 1-, 3- and 5-year survival rates were 42, 11 and 3%, respectively, with mean survival of 15 months in all patients. In the univariate analysis, the following six variables were significantly associated with prognosis: (i) tumor response; (ii) ascites; (iii) accumulation of iodized oil in tumor thrombi; (iv) in main tumors; (v) Okuda classification; and (vi) tumor size. In the multivariate analysis, the first three of these factors showed significantly independent values for patient prognosis. CONCLUSION Chemoembolization appears to be an effective treatment for HCCs invading the portal venous system. The prognostic factors identified here are expected to be helpful in classifying patients with HCCs invading the portal veins and should serve as useful guidelines for chemoembolization in clinical practice.

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.

Optimal Scan Parameters for CT Fluoroscopy in Lung Interventional Radiologic Procedures: Relationship between Radiation Dose and Image Quality

PURPOSE To evaluate the relationship between radiation doses and lung computed tomographic (CT) fluoroscopic scan parameters and to determine optimal scan parameters for performance of lung interventional radiologic (IR) procedures. MATERIALS AND METHODS The institutional review board approved this prospective study, which included 32 patients with a single lung tumor; written informed consent was obtained. CT fluoroscopic images were obtained with three tube voltages (80,120,135 kV) and three tube currents (10, 20, 30 mA) in each patient. The signal-to-noise ratios (SNRs) and the contrast-to-noise ratios (CNRs) were measured quantitatively. To evaluate the feasibility of performing lung IR procedures, four readers visually scored the image quality. Acceptable CT fluoroscopic images were determined by using agreement of at least three of the four readers. The weighted CT dose index for each CT scan parameter was measured. A piecewise linear regression equation was obtained from the relationship between radiation doses and visual image scores. RESULTS Both the SNR and the CNR improved as the radiation dose increased, leading to improvement in the image quality. Acceptable image quality was achieved in 94% (30 of 32) of patients when the radiation dose was 1.18 mGy/sec (120 kV, 10 mA) and in all patients when it was greater than 1.48 mGy/sec (135 kV, 10 mA). The piecewise linear curve showed rapid improvement in image quality until the radiation dose increased to 1.48 mGy/sec (135 kV, 10 mA). When the radiation dose was increased greater than 1.48 mGy/sec, improvement in the image quality became more gradual. CONCLUSION Results of this study can be used to guide the determination of optimal scan parameters in lung CT fluoroscopy.

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.