Yoon Suk Kim

Benign Predominantly Solid Thyroid Nodules: Prospective Study of Efficacy of Sonographically Guided Radiofrequency Ablation Versus Control Condition

OBJECTIVE The purpose of this study was to evaluate the efficacy of radiofrequency ablation of benign predominantly solid thyroid nodules by comparing the findings in treatment and control groups. SUBJECTS AND METHODS Thirty patients with normal thyroid function, each with a benign predominantly (> 50%) solid thyroid nodule causing pressure symptoms or cosmetic problems, were assigned to a control group (n = 15) or to a group undergoing a single session of radiofrequency ablation (n = 15). Thyroid nodule volume, thyroid function, pressure symptoms, and cosmetic concerns were evaluated before treatment and during follow-up. Sonographically guided radiofrequency ablation was performed with an internally cooled electrode (1-cm active tip) with an output power of 30-80 W. RESULTS The control group had no resolution of symptoms or cosmetic problems. The mean nodule volume increased slightly after 6 months but without statistical significance (p = 0.46). In the radiofrequency ablation group, the mean symptom score (p = 0.001) and cosmetic grade (p = 0.001) improved significantly. Mean nodule volume decreased significantly from 7.5 +/- 4.9 mL (range, 1.7-20.0 mL) to 1.3 +/- 0.8 mL (range, 0.2-2.6 mL) 6 months after radiofrequency ablation (p = 0.001). There were no major complications of ablation. CONCLUSION This study confirmed that radiofrequency ablation is effective for reducing nodule volume and relieving nodule-related clinical problems and that an effect due to spontaneous nodule reduction can be excluded owing to the results of the comparison with a similar control group.

Radiofrequency ablation of benign Thyroid nodules and recurrent Thyroid cancers: Consensus statement and recommendations

Thermal ablation using radiofrequency is a new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology has developed recommendations for the optimal use of radiofrequency ablation for thyroid nodules. These recommendations are based on a comprehensive analysis of the current literature, the results of multicenter studies, and expert consensus.

Optimum First-Line Treatment Technique for Benign Cystic Thyroid Nodules: Ethanol Ablation or Radiofrequency Ablation?

OBJECTIVE The purpose of this article is to compare the efficacy and safety of ethanol ablation and radiofrequency ablation (RFA) used as treatment of benign cystic thyroid nodules. MATERIALS AND METHODS Fifty-seven patients (44 women and 13 men) with benign cystic nodules (cystic portions > 90%) inducing pressure symptoms or cosmetic problems were treated with ethanol ablation (n = 36) or RFA (n = 21). Ethanol ablation was performed using 16- or 18-gauge needles with 95-99% ethanol, and RFA used a cooled-electrode RFA system and 17- or 18-gauge internally cooled electrodes. Of nine viscous nodules, five were treated with ethanol ablation and four with RFA, with all except for one nodule in the RFA group being treated only after evacuation of internal colloid material. Nodule volume, symptom score (0-10), cosmetic score (1-4), and complications were evaluated before and after treatment. RESULTS Both ethanol ablation and RFA resulted in significant decreases in nodule volume (p < 0.001), symptom score (p < 0.001), and cosmetic score (p < 0.001). There were no between-group differences in mean volume reduction (p = 0.15), decreases in symptoms (p = 0.53), cosmetic scores (p = 0.69), or therapeutic success rate (p = 0.61). However, the mean number of treatment sessions was significantly lower in the ethanol ablation than in the RFA group (p = 0.026). No serious complications were encountered in either group. CONCLUSION Ethanol ablation yielded similar results with fewer treatment sessions compared with RFA. Because ethanol ablation is also less expensive and simpler to perform than RFA, our findings suggest that ethanol ablation, rather than RFA, should be the first-line treatment technique for benign predominantly cystic thyroid nodules.

Locoregional Control of Metastatic Well-Differentiated Thyroid Cancer by Ultrasound-Guided Radiofrequency Ablation

OBJECTIVE The purpose of this study was to evaluate the efficacy and safety of ultrasound-guided radiofrequency ablation (RFA) in the control of metastatic well-differentiated thyroid carcinoma in patients for whom surgery is not feasible. MATERIALS AND METHODS Between December 2004 and June 2008, 12 metastatic differentiated thyroid carcinomas (mean diameter, 13.8 mm; range, 4-28 mm) in 10 patients (six women, four men; mean age, 44.8 years) were treated with RFA. The inclusion criteria for RFA were fewer than three metastatic tumors confirmed with ultrasound-guided fine-needle aspiration biopsy, no metastatic tumor beyond the neck at RFA, and infeasibility of surgery. A radiofrequency generator and 18-gauge internally cooled electrodes with a 7-cm shaft length and 0.5- and 1-cm active tips were used depending on the size of the targeted tumors. Ten of the 12 metastatic tumors (83%) were treated in a single session of RFA, and the other two required two sessions. The ablation time ranged from 60 to 900 seconds. RESULTS After treatment, the mean largest diameter decreased significantly from 13.8 ± 7.0 mm to 3.3 ± 3.9 mm (p = 0.002), as did mean volume, from 55.5 ± 50.3 mm(3) to 5.7 ± 9.3 mm(3) (p = 0.002). At the last follow-up evaluation, the serum thyroglobulin concentration had decreased in 7 of 10 patients. One patient had dysphonia immediately after RFA of a left surgical bed. CONCLUSION Although surgery is the standard treatment of locally metastatic thyroid cancer, RFA is effective for locoregional control of metastatic well-differentiated thyroid carcinoma in patients for whom surgery is infeasible.

One-step ethanol ablation of viscous cystic thyroid nodules.

OBJECTIVE The purpose of this study was to evaluate the efficacy and safety of one-step ethanol ablation in the management of viscous cystic thyroid nodules. MATERIALS AND METHODS Viscous cystic thyroid nodules are defined as nodules that cannot be aspirated with an 18-gauge needle. Nine euthyroid patients underwent one-step ethanol ablation of benign single compressive viscous cystic thyroid nodules (cystic portion > 90%). The thick content of the nodules was removed with either a 16-gauge needle (n = 8) or an 8.5-French pigtail catheter (n = 1) connected to a suction pump. An injection of 99% sterile ethanol then was administered. After 10 minutes, all of the injected ethanol was withdrawn. Additional treatment was prescribed if the cystic portion of the nodule remained larger than 1 mL. Follow-up sonography was performed 1 and 6 months after treatment. At each follow-up examination, nodule volume, symptom score (centimeter visual analog scale, 0-10), cosmetic grade (grade 1-4), and complications were evaluated. RESULTS The mean volume of index nodules was 24.4 +/- 20.3 (SD) mL (range, 4.5-57.4 mL). The mean amount of ethanol injected was 11.8 +/- 10.1 mL (range, 2-27 mL). The mean total procedure time was 27.8 +/- 10.4 minutes (range, 15-45 minutes). One month after ablation, the mean volume of the nodules had decreased significantly (7.2 +/- 9.4 vs 24.4 +/- 20.3 mL, p = 0.008). Additional reduction was found at the 6-month follow-up examination, the mean nodule volume being 2.1 +/- 3.8 mL (p = 0.008). The mean volume reductions at 1 and 6 months were 78.4% +/- 14.4% and 93.6% +/- 6.8%. The mean symptom score decreased from 3.2 +/- 1.5 to 0.4 +/- 1.0 (p < 0.05) and the mean cosmetic grade from 3.9 +/- 0.3 to 1.3 +/- 0.7 (p < 0.05). No major complications were encountered. CONCLUSION One-step ethanol ablation is an effective and safe method of management of viscous cystic thyroid nodules.

Diagnostic Benefit of Thyroglobulin Measurement in Fine-Needle Aspiration for Diagnosing Metastatic Cervical Lymph Nodes from Papillary Thyroid Cancer: Correlations with US Features

Objective Our goals were to determine the added value of fine-needle aspiration biopsy (FNAB)-thyroglobulin (Tg) measurements over FNAB-cytology alone for diagnosing metastatic nodes, and to determine whether the ultrasound features of lymph nodes can be used to identify lymph nodes that may benefit from FNAB-Tg measurement in patients with papillary thyroid cancer. Materials and Methods We retrospectively evaluated 76 surgically proven cervical lymph nodes. Twenty-nine patients were awaiting surgery and 18 patients had undergone thyroid surgery for papillary thyroid cancer. Ultrasound-guided FNAB and Tg measurements were performed and the ultrasound features were evaluated. Results The accuracies, sensitivities, and specificities of FNAB-cytology, FNAB-Tg, and combined FNAB-Tg/cytology were 90%, 80%, and 100%; 92%, 95%, and 90%; and 93%, 96%, and 90%, respectively. The diagnostic sensitivity of FNAB-Tg for metastatic nodes was significantly higher than that of FNAB-cytology (p = 0.011). Furthermore, combined FNAB-Tg/cytology significantly increased sensitivity (p = 0.002) and accuracy (p = 0.03) as compared with FNAB-cytology. Conclusion Combined FNAB-Tg/cytology is significantly more sensitive and accurate at detecting metastatic nodes than FNAB-cytology alone. FNAB-Tg was better at diagnosing metastases in small lymph nodes.