Efficacy and safety of thermal ablation for autonomously functioning thyroid nodules: a systematic review and meta-analysis.

BACKGROUND: Although thermal ablation has been regarded as an alternative treatment option for autonomously functioning thyroid nodules (AFTNs), the efficacy of this treatment in patients with AFTNs has not yet been systematically evaluated. In this systematic review and meta-analysis, we aimed to evaluate the efficacy and safety of thermal ablation in the treatment of AFTN, and identify the factors affecting the effectiveness of the treatment. METHODS: Ovid-MEDLINE and Embase databases were searched for studies reporting the efficacy and safety of thermal ablation for patients with AFTN published up until January 6, 2020. Data extraction and quality assessment were performed by two radiologists according to PRISMA guidelines. The primary and secondary outcomes were to yield the pooled proportions of thyroid-stimulating hormone (TSH) normalization and pooled estimates of volume reduction rate (VRR), respectively. Subgroup analyses were performed to identify factors affecting the treatment efficacy. RESULTS: This systematic review identified 411 AFTNs treated by thermal ablation in 391 patients in 14 studies. TSH normalization was achieved in 71.2% of patients and the volume reduction rate was 69.4% at a mean follow-up period of 12.8 months. No patients experienced hypothyroidism or a life-threatening complication during follow-up. Subgroup analyses according to nodule volume did not find a significant difference in TSH normalization (p = 0.54) or VRR (p = 0.94). CONCLUSIONS: Thermal ablation is an effective and safe treatment method for patients with AFTNs. The nodule volume did not affect the efficacy of thermal ablation, and this result should be considered in future thermal ablation guidelines. KEY POINTS: • Thermal ablation has good efficacy and safety in the treatment of autonomously functioning thyroid nodule. • The efficacy of thermal ablation was not affected by nodule volume.

Long-Term Results of Thermal Ablation of Benign Thyroid Nodules: A Systematic Review and Meta-Analysis.

BACKGROUND: Ultrasound-guided thermal ablations have become one of the main options for treating benign thyroid nodules. To determine efficacy of thermal ablation of benign thyroid nodules, we performed a meta-analysis of studies with long-term follow-up of more than 3 years. METHODS: Databases were searched for studies published up to August 25, 2019, reporting patients with benign thyroid nodules treated with thermal ablation and with follow-up data of more than 3 years. Data extraction and quality assessment were performed according to PRISMA guidelines. The analysis yielded serial volume reduction rates (VRRs) of ablated nodules for up to 3 years or more, and adverse effect of ablation during follow-up. Radiofrequency ablation (RFA) and laser ablation (LA) were compared in a subgroup analysis. RESULTS: The pooled VRRs for ablated nodules showed rapid volume reduction before 12 months, a plateau from 12 to 36 months, and more volume reduction appearing after 36 months, demonstrating long-term maintenance of treatment efficacy. Thermal ablation had an acceptable complication rate of 3.8%. Moreover, patients undergoing nodule ablation showed no unexpected delayed complications during the follow-up period. In the subgroup analysis, RFA was shown to be superior to LA in terms of the pooled VRR and the number of patients who underwent delayed surgery. CONCLUSION: Thermal ablations are safe and effective methods for treating benign thyroid nodules, as shown by a long follow-up analysis of more than 3 years. In addition, RFA showed superior VRRs compared with LA for the treatment of benign thyroid nodules, with less regrowth and less delayed surgery.

Estimating the Growth Rate of Lung Metastases in Differentiated Thyroid Carcinoma: Response Evaluation Criteria in Solid Tumors or Doubling Time?

Background: Estimating the growth rate of lung metastases for the treatment of patients with metastases of differentiated thyroid carcinoma (DTC) is important. This study aimed to evaluate survival outcomes according to different criteria for estimating the growth rate of lung metastases. Methods: Patients with macronodular (≥1 cm) lung metastases of DTC who underwent total thyroidectomy and high-dose radioactive iodine therapy between 1995 and 2013 were enrolled. The time to progressive disease (PD) by the Response Evaluation Criteria in Solid Tumors (RECIST), average tumor volume doubling time of the two dominant target lung lesions (midDT), and thyroglobulin doubling time (TgDT) were measured in each patient, and their association with disease-specific survival (DSS) was evaluated. Results: Forty-four patients with target lung metastatic nodules with an initial maximal diameter of 1.3 cm (median) were followed-up for a median of 6.8 years after the diagnosis of lung metastases. Based on RECIST, 12 patients (27.3%) showed fast tumor progression, with time to PD <1 year. When assessed by midDT, nine patients (20.5%) had midDT ≤1 year, showing rapid tumor progression. Seven of 33 patients (21.2%) who were negative for thyroglobulin antibody had midDT <1 year. Growth rates assessed by all three criteria were significantly associated with DSS. However, midDT had the highest predictive value for DSS, with a proportion of variation explained of 33.6%. Five-year DSS was 29.6% in patients with midDT ≤1 year, 50.0% in patients with time to PD <1 year, and 42.9% in patients with TgDT <1 year. Conclusions: Among the different criteria for estimating the growth rate of metastases in patients with lung metastases of DTC, midDT was the most powerful for predicting DSS, in comparison with RECIST and TgDT. Performing at least three serial chest computed tomography scans during the first year from the diagnosis of lung metastases can facilitate early detection of patients with rapid tumor progression and provide objective guidance for initiation of systemic therapy.

US Fine-Needle Aspiration Biopsy for Thyroid Malignancy: Diagnostic Performance of Seven Society Guidelines Applied to 2000 Thyroid Nodules.

Purpose To compare the diagnostic performance of ultrasonography (US)-based fine-needle aspiration biopsy (FNAB) criteria from seven international societies in the detection of thyroid malignancy. Materials and Methods This study included a total of 2000 consecutive thyroid nodules (≥1 cm) in 1802 patients with final diagnoses from January 2010 to May 2011. US features of the thyroid nodules were retrospectively reviewed and were classified according to the categories defined by the seven international society guidelines. The diagnostic performance of US-based FNAB criteria in the detection of thyroid malignancy and unnecessary FNAB rates were calculated and compared by using a generalized estimating equation method. Results Of the 2000 thyroid nodules, 1546 (78.3%) were benign and 454 (22.7%) were malignant, with papillary carcinoma comprising 85.5% of all malignancies. The Korean Thyroid Association/Korean Society of Thyroid Radiology (KTA/KSThR) (94.5%), National Comprehensive Cancer Network (NCCN) (92.5%), and American Thyroid Association (ATA) (89.6%) guidelines were more sensitive than those of the American Association of Clinical Endocrinologists/American College of Endocrinology/Associazione Medici Endocrinologi (AACE/ACE/AME) (80.4%), American College of Radiology (ACR) (74.7%), French Society of Endocrinology (FSE) (72.7%), and Society of Radiology in Ultrasound (SRU) (70.9%) (P < .001), while the latter guidelines had higher specificity (P < .001). The rate of unnecessary FNAB was lowest with the ACR guidelines (25.3%), followed by the FSE (29.1%), AACE/ACE/AME (32.5%), SRU (45.2%), ATA (51.7%), NCCN (54.0%), and KTA/KSThR (56.9%) guidelines. Conclusion Because the diagnostic performance of US-based FNAB criteria varies according to the individual international society guidelines, clinicians should be aware of the strengths and weaknesses of US-based FNAB criteria in the management of thyroid nodules. © RSNA, 2018 Online supplemental material is available for this article.

Clinical outcomes of persistent radioiodine uptake in the neck shown by diagnostic whole body scan in patients with differentiated thyroid carcinoma after initial surgery and remnant ablation.

OBJECTIVES: To evaluate the clinical outcomes of persistent radioiodine uptake (RAIU) in the neck by diagnostic whole body scan (DxWBS) after initial therapy and the efficacy of the second ablation in patients with differentiated thyroid carcinoma (DTC). DESIGN: Patients with DTC who underwent bilateral surgery and high-dose remnant ablation between 2000 and 2004 were included. Patients with elevated serum stimulated thyroglobulin (sTg) or extensive lateral neck lymph node involvement at initial surgery underwent a second ablation, and patients with undetectable sTg or in very low-risk groups were observed. RESULTS: Among 572 patients, 25 had persistent RAIU in the neck at first DxWBS. After a median 65.7 months of follow-up, five of these patients (20%) had persistent disease, whereas another 20 patients had no abnormal findings by ultrasonography (US) or other imaging modalities. Seven of 20 patients underwent second ablation and 13 were observed. RAIU disappeared spontaneously in about half of the patients in the observation group. There were no significant between-group differences in change of RAIU at follow-up DxWBS (P = 0.62). Serum sTg decreased and eventually disappeared over a few years in both groups. Ablation failure was not an independent risk factor for recurrence (P = 0.169). CONCLUSIONS: Neck US and serum sTg, but not DxWBS, were useful diagnostic tools during follow-up of patients with persistent uptake in the neck at DxWBS. A second ablation was not necessary when neck US showed no evidence of disease, especially in patients with very low sTg concentration.

Empiric high-dose 131-iodine therapy lacks efficacy for treated papillary thyroid cancer patients with detectable serum thyroglobulin, but negative cervical sonography and 18F-fluorodeoxyglucose positron emission tomography scan.

CONTEXT: Some patients with elevated serum thyroglobulin (Tg) but a negative diagnostic whole body scan (WBS) after initial therapy for differentiated thyroid carcinoma may benefit from empirical radioactive iodine (RAI) therapy. However, previous studies enrolled patients with negative diagnostic WBS, regardless of neck ultrasonography (USG) and/or (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET), which have become the preferred diagnostic procedures in such patients. OBJECTIVE: The aim of this study was to evaluate the usefulness of empirical RAI therapy in patients with elevated stimulated Tg level and negative USG/FDG-PET findings after initial therapy for papillary thyroid carcinoma (PTC). DESIGN: This comparative study enrolled 39 patients with elevated stimulated Tg, negative diagnostic WBS, and negative USG/FDG-PET 1 yr after initial treatment. Empirical RAI therapy was performed in 14 patients (treatment group), whereas 25 patients were followed up without therapy (control group). RESULTS: There was no significant between-group difference in basal clinicopathological parameters. None of the 14 patients in the treatment group showed iodine uptake on posttreatment WBS. Five of 14 patients (36%) in the treatment group and eight of 25 (32%) in the control group had recurrence during the median 37 months of follow-up (P = 0.99). Changes in serum stimulated Tg concentrations did not differ between the two groups. CONCLUSION: Empirical RAI therapy and posttreatment WBS were not useful diagnostically or therapeutically in patients with positive serum stimulated Tg if such patients had negative USG and negative FDG-PET findings after initial treatment of PTC.