• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6637-6641
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• 2013

Background: To evaluate the results of various types of radiofrequency ablation (RFA) treatment of renal tumors in patients with excessive anesthetic and surgical risk. Materials and Methods: Data for RFA performed in in high risk patients were retrospectively evaluated. Other RFA applications in patients with no anesthetic and/or surgical risk were excluded. RFA was by ultrasound or CT guided percutaneous (USG/CT-PRFA) and retroperitoneally or transperitoneally laparoscopic (R/T-LRFA) techniques under general or local anethesia. Follow-up data of enhanced CT or MRI after 1, 3 and 6 months were analysed for twelve RFA applications. Results: The RFA applications included 4 (40%) left-sided, 5 (50%) right-sided and 1 (10%) bilaterally RFA (simultaneously 1 right and 2 left). The localizations of tumors were 2 (16.6%) upper, 5 (41.6%) mid and 5 (41.6%) lower pole. The RFA applications included 9 (75%) USG-PRFA, 1 (8.3%) CT-PRFA, 1 (8.3%) T-LRFA and 1 (8.3%) R-LRFA. The mean age was $65.3{\pm}8.5$ (52-76) years. The mean tumor size was $29.6{\pm}6.08$ (15-40) mm. No complications related to the RFA were encountered in any of the cases. Failure (residual tumour) was determined in 8.3% (1/12) of USG-RFA application. The success rate was thus 91.7% (11/12). Other 1st, 3rd and 6th months follow-up data revealed no residua and recurrence. Conclusions: RFA application appears to be safe as a less invasive and effective treatment modality in selected cases of small renal tumors in individuals with excessive anesthetic and also surgical risk.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6159-6162
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• 2015

Purpose: To evaluate efficacy of transarterial chemoembolization (TACE) combined with radiofrequency ablation (RFA) in treatment of patients with hepatocellular carcinoma. Materials and Methods: During January 2009 to March 2012, 80 patients with hepatocellular carcinoma underwent TACE, with or without RFA. Alfafetoprotein (AFP) was checked before and after procedure. CT scans were obtained one month after TACE or RFA for all patients to evaluate tumor changes. Complete response+partial response+stable disease (CR+PR+SD)/n were used to assess the disease control rate (DCR). Survival at 3, 6 and 12 months was compared in both groups. Results: AFP levels in TACE + RFA group dropped rapidly, becoming obviously lower than that of the TACE group. In the TACE + RFA group DCR was 93.8%, while only 76.8% in the TACE group. The treatment effect between the two groups was statistically significant (P<0.05) by Ridit analysis. 1 year survival rate in the TACE + RFA group was 92.5%, significantly higher than that of the TACE group at 77.5% (P<0.05). Conclusions: TACE and RFA as combined therapy method for patients with middle and terminal stage HCC gives full play to synergy between the two and improves the therapeutic effect.

• Journal of Sensor Science and Technology
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• v.17 no.6
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• pp.397-405
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• 2008

In this study, we have measured temperature distribution using infrared optical fibers during radiofrequency ablation (RFA). Infrared radiations generated from the water around inserted electrode are transferred by silver halide optical fibers and are measured by a thermopile sensor. Also, the output voltages of a thermopile sensor are compared with those of the thermocouple recorder. It is expected that a noncontact temperature sensor using an infrared optical fiber can be developed for the temperature monitoring during RFA treatments based on the results of this study.

• Korean Journal of Radiology
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• v.19 no.6
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• pp.1130-1139
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• 2018

Objective: To compare the therapeutic efficacy between conventional transarterial chemoembolization (cTACE) and combined therapy using cTACE and radiofrequency ablation (RFA) in ultrasound (US)-invisible early stage hepatocellular carcinoma (HCC). Materials and Methods: From January 2008 to June 2016, 167 patients with US-invisible early stage HCCs were treated with cTACE alone (cTACE group; n = 85) or cTACE followed by immediate fluoroscopy-guided RFA targeting intratumoral iodized oil retention (combined group; n = 82). Procedure-related complications, local tumor progression (LTP), time to progression (TTP), and overall survival (OS) were compared between the two groups. Multivariate analyses were performed to identify prognostic factors. Results: There was no major complication in either group. The cTACE group showed higher 1-, 3-, and 5-year LTP rates than the combined group; i.e., 12.5%, 31.7%, and 37.0%, respectively, in the cTACE group; compared to 7.3%, 16.5%, and 16.5%, respectively, in the combined group; p = 0.013. The median TTP was 18 months in the cTACE group and 24 months in the combined group (p = 0.037). Cumulative 1-, 3-, and 5-year OS rates were 100%, 93.2%, and 87.7%, respectively, in the cTACE group and 100%, 96.6%, and 87.4%, respectively, in the combined group (p = 0.686). Tumor diameter > 20 mm and cTACE monotherapy were independent risk factors for LTP and TTP. Conclusion: Combined therapy using cTACE followed by fluoroscopy-guided RFA is a safe and effective treatment in US-invisible early stage HCCs. It provides less LTP and longer TTP than cTACE alone.

• Korean Journal of Radiology
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• v.19 no.6
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• pp.1053-1065
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• 2018

Objective: To evaluate the clinical impact of using registration software for ablative margin assessment on pre-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) and post-RFA computed tomography (CT) compared with the conventional side-by-side MR-CT visual comparison. Materials and Methods: In this Institutional Review Board-approved prospective study, 68 patients with 88 hepatocellulcar carcinomas (HCCs) who had undergone pre-RFA MRI were enrolled. Informed consent was obtained from all patients. Pre-RFA MRI and post-RFA CT images were analyzed to evaluate the presence of a sufficient safety margin (${\geq}3mm$) in two separate sessions using either side-by-side visual comparison or non-rigid registration software. Patients with an insufficient ablative margin on either one or both methods underwent additional treatment depending on the technical feasibility and patient's condition. Then, ablative margins were re-assessed using both methods. Local tumor progression (LTP) rates were compared between the sufficient and insufficient margin groups in each method. Results: The two methods showed 14.8% (13/88) discordance in estimating sufficient ablative margins. On registration software-assisted inspection, patients with insufficient ablative margins showed a significantly higher 5-year LTP rate than those with sufficient ablative margins (66.7% vs. 27.0%, p = 0.004). However, classification by visual inspection alone did not reveal a significant difference in 5-year LTP between the two groups (28.6% vs. 30.5%, p = 0.79). Conclusion: Registration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-RFA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA.

• BMB Reports
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• v.52 no.4
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• pp.277-282
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• 2019

Currently speaking, it is noted that radiofrequency ablation (RFA) has been the most widely used treatment for hepatocellular carcinoma (HCC) occurring in patients. However, accumulating evidence has demonstrated that the incidence of insufficient RFA (IRFA) may result in the identified rapid progression of residual HCC in the patient, which can greatly hinder the effectiveness and patient reported benefits of utilizing this technique. Although many efforts have been proposed, the underlying mechanisms triggering the rapid progression of residual HCC after IRFA have not yet been fully clarified through current research literature reviews. It was shown in this study that cell proliferation, migration and invasion of residual HepG2 and SMMC7721 cells were significantly increased after the IRFA was simulated in vitro. In other words, it is noted that IRFA could do this by enhancing the image of autophagy of the residual HCC cell via the $HIF-1{\alpha}/BNIP3$ pathway. Consequently, the down-regulation of BNIP3 may result in the inhibition of the residual HCC cell progression and autophagy after IRFA. Our present study results suggest that IRFA could promote residual HCC cell progression in vitro by enhancing autophagy via the $HIF-1{\alpha}/BNIP3$ pathway. For this reason, it is noted that the targeting of the BNIP3 may be useful in preventing the rapid growth and metastasis of residual HCC after IRFA.

• The Korean Journal of Pain
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• v.36 no.4
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• pp.450-457
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• 2023

Background: Genicular nerve neurolysis with phenol and radiofrequency ablation (RFA) are two interventional techniques for treating chronic refractory knee osteoarthritis (KOA) pain. This study aimed to compare the efficacy and adverse effects of both techniques. Methods: Sixty-four patients responding to diagnostic blockade of the superior medial, superior lateral, and inferior medial genicular nerve under ultrasound guidance were randomly divided into two groups: Group P (2 mL phenol for each genicular nerve) and Group R (RFA 80℃ for 60 seconds for each genicular nerve). The numeric rating scale (NRS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used to evaluate the effectiveness of the interventions. Results: RFA and phenol neurolysis of the genicular nerves provided effective analgesia within groups at 1 week, 1 month, and 3 months compared to baseline. There was no significant difference between the groups in terms of NRS and WOMAC scores at all measurement times. At the 3rd month follow-up, 50% or more pain relief was observed in 53.1% of patients in Group P and 50% of patients in Group R. The rate of transient paresthesia was 34.4% in Group P and 6.3% in Group R, and this was significantly higher in Group P. Conclusions: Neurolysis of the genicular nerves with both RFA and phenol is effective in the management of KOA pain. Phenol may be a good alternative to RFA. Further studies are needed on issues such as dose adjustment to prevent transient paresthesia response.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.710-718
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• 2009

Background: The Cox maze procedure has been used as a standard surgical treatment for atrial fibrillation for about 20 years. Recently, the creators have used a bipolar radiofrequency electrode (Cox maze IV procedure) instead of the incision and suture (cut-sew) technique to make atrial ablation lesions for persistent atrial fibrillation. We investigated clinical outcomes for the Cox maze procedure with a bipolar radiofrequency electrode and cryoablator in patients with persistent atrial fibrillation, and compared results with clinical outcomes of the cut-sew procedure. Material and Method: Between April 2005 and July 2007, 40 patients with persistent atrial fibrillation underwent Cox maze IV procedure with a bipolar radiofrequency electrode and cryoablator (bipolar radiofrequency group). Surgical outcomes were compared with those of 35 patients who had the cut-sew technique for the Cox maze III procedure. All patients had concomitant cardiac surgery. Postoperatively, the patients were followed up every 1 to 2 months. Result: At 6 months postoperatively, the conversion rate to regular sinus rhythm was not significantly different between the two groups: 95.0% for the bipolar radiofrequency ablation group; 97.1% for the cut-sew technique (p=1.0). At the end of the follow-up period, the conversion rate to regular sinus rhythm was also not significantly different (92.5% vs. 91.6%, p=1.0). In multivariate analysis using a Cox-regression model, the postoperative atrial dimension was an independent determinant of sinus conversion in the bipolar radiofrequency ablation group (hazard ratio 31, p=0.005). In the Cox-regression model for both groups, atrial fibrillation at 6 months postoperatively (hazard ratio 92.24, p=0.003) and the postoperative left atrial dimension (hazard ratio 16.05, p=0.019) were independent risk factors of continuance or recurrence of atrial fibrillation after Cox maze procedures. Aortic cross-clamp time and cardiopulmonary bypass time were significantly shorter in the radiofrequency group than in the cut-sew group. Conclusion: In the Cox maze procedure for patients with persistent atrial fibrillation, the use of bipolar radiofrequency ablation and a cryoablator is as good as the cut-sew technique for conversion to sinus rhythm. The postoperative left atrial dimension is an independent determinant of postoperative continuance and recurrence of atrial fibrillation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.4
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• pp.435-444
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• 2008

Purpose: Clinical study to evaluate the efficacy and the safety of various surgical treatments in snoring and obstructive sleep apnea. Methods and materials: We performed surgical treatments such as radiofrequency ablation, uvulopalatopharyngoplasty(UPPP) with tonsillectomy, uvulopalatopharyngoplasty with advancement genioplasty, orthognathic surgery(maxillomandibluar advancement), distraction osteogenesis device insertion. Diagnosis was performed with clinical examination, polysomnography, lateral cephalometric and computed tomography. 62(M : F = 45 : 17, mean age 41.5, mean follow-up 4 weeks) patients underwent radiofrequency ablation and 7 (M : F = 5 : 2, mean age 38.9, mean follow-up 19months)patients experienced uvulopalatopharyngoplasty with tonsillectomy. Uvulopalatophayngoplasty with advancement genioplasty was performed for 3 (M : F = 2: 1, mean age 30.2, mean follow-up 14 months)patients. The last 3(M : F = 2 : 1, mean age 21.5, mean follow-up 24 months)patients was treated with orthognathic surgery including distraction device insertion. The results was evaluated by questionnaires, polysomnography, investigation of complications. Results: Of the patients treated with radiofrequency ablation, 95% reported improvement of their symptom. 100% improvement was reported in patients treated with UPPP with tonsillectomy and UPPP with advancement genioplasty. The two of three patients who underwent orthognathic surgery showed the satisfactory of treatments. Dryness of mouth was the most common complication during short period in radiofrequency ablation and UPPP with tonsillectomy. Relapse complication was not found in any surgical treatments. Conclusion: Treatment for snoring and OSA is determined by severity degree of the physiologic derangements, predominant type of apnea and obstructive site. Accuracy diagnosis should be performed prior to treatment for satisfactory treatment result. This study demonstrates feasibility, safety and efficacy of surgical treatments in snoring and OSA.

• Journal of the Korean Society of Radiology
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• v.79 no.6
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• pp.323-331
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• 2018

Purpose: The purpose of this study was to evaluate the effectiveness of thoracic paravertebral block (TPVB) for management of pain during and after percutaneous radiofrequency ablation (RFA) of hepatic tumor. Materials and Methods: All patients were divided into non-TPVB (4 patients, 4 sessions of RFA for 4 tumors) and TPVB group (5 patients, 7 sessions of RFAs for 7 tumors). Ultrasound (US)-guided TPVB was performed at T7 level. The 15 mL of 0.375% ropivacaine was injected into right paravertebral space before RFA. If patients complained pain and asked analgesics or experienced pain with verbal numerical rating scale (VNRS) of more than 4, fentanyl $25{\mu}g$ (up to $100{\mu}g$), pethidine 25 mg, and midazolam 0.05 mg/kg (up to 5 mg) were sequentially given intravenously during RFA. Results: Total intravenous morphine equivalence of analgesics before, during, and after RFA was 129.1 mg and 0.0 mg in non-TPVB and TPVB group, respectively. Conclusion: US-guided TPVB may be an effective and safe anesthetic method for decreasing or eliminating pain during and after RFA for hepatic tumor and helpful in decreasing the usage of opioids.