Objective: Current guidelines recommend surveillance or diagnostic lobectomy for indeterminate thyroid nodules. Although radiofrequency ablation (RFA) has emerged as a potential alternative, its role remains controversial. Functional imaging modalities, including 99mTc-methoxyisobutylisonitrile scintigraphy and 18 F-fluorodeoxyglucose positron emission tomography, have been used to support risk stratification. This study evaluated the mid-term outcomes of RFA and their predictors in a functionally screened cohort of patients with indeterminate thyroid nodules. Materials and Methods: This retrospective cohort study included 109 patients with Bethesda category III or IV thyroid nodules who underwent RFA after functional imaging–based evaluation between January 2018 and November 2024. The primary outcome was local treatment failure (LTF), defined as the first occurrence of nodule regrowth, an increase in vital volume, or repeated indeterminate cytology. The secondary outcome was complete disappearance of the nodule.Supplementary outcomes included the volume reduction rate, symptom and cosmetic scores, and biochemical markers. Results: During a median follow-up of 2.2 years (range, 0.7–6.8 years), LTF occurred in 15 of 109 patients (13.8%), whereas complete disappearance was observed in 9 (8.3%) patients. The 3-year LTF-free probability and cumulative incidence of complete disappearance were 85.4% and 6.5%, respectively. Significant reductions were observed in the nodule volume, symptom scores, cosmetic scores, and free T4 and thyroglobulin levels. A greater initial maximum nodule diameter was independently associated with a higher likelihood of LTF (hazard ratio [HR] per 1-cm increase, 2.35; 95% confidence interval [CI], 1.23–4.48; P = 0.010) and a lower likelihood of complete disappearance (HR, 0.16; 95% CI, 0.04–0.60; P = 0.006). At 3 years, 93% of the tumors with an initial diameter <3.0 cm remained free of LTF, whereas no tumors >2.1 cm achieved complete disappearance. Conclusion In this functionally screened cohort of patients with indeterminate thyroid nodules, RFA demonstrated acceptable outcomes with volume reduction and symptom relief, particularly in patients with nodules <3 cm.

BACKGROUNDCongenital long QT syndrome (LQTS) is an ion channelopathy associated with genetic mutations. It is well known that most LQTS patients (91%) have a single mutation. The purpose of this study was to investigate the clinical characteristics of congenital LQTS patients with bigenic mutations in Taiwan, China.

METHODSCongenital LQTS patients were recruited consecutively at Taiwan University Hospital in Taiwan from 2003 to 2009. The diagnosis of LQTS was defined by an LQTS Schwartz score greater than 4. Mutation screening in KCNQ1, KCNH2, KCNE1, and SCN5A was performed using direct sequencing.

RESULTSThree of 16 LQTS patients (18.7%) were identified with bigenic mutations. One patient had missense mutations in KCNQ1 and KCNH2, the second in KCNQ1 and KCNE1, and the third in KCNH2 and SCN5A. The mean age at onset of LQTS for patients with bigenic mutations was (17 ± 3) years, and all of these patients were female. Two of them experienced seizure and one presented with syncope, although one of them had a family history of syncope. The mean QTc interval was (515 ± 17) ms, similar to those with single mutation or SNPs ((536 ± 74) ms, P = 0.63). Compared to those LQTS patients with single mutation or SNPs, a significantly higher percentage of LQTS patients with bigenic mutations presented with seizure and were younger at onset of the first index event (P = 0.03 and 0.001, respectively), but lower percentage of them presented with sudden cardiac death (P = 0.03).

CONCLUSIONSAlthough the percentage of bigenic mutations in LQTS is less than 10% in Caucasian populations, we identified 3 of 16 LQTS patients (18.7%, 95% confidence interval: 0.04-0.46) with bigenic mutations in Taiwan. However, the severity of their clinical presentations was not higher than those patients with single mutation or SNPs.

Adolescent ; Adult ; Aged ; ERG1 Potassium Channel ; Ether-A-Go-Go Potassium Channels ; genetics ; Female ; Genotype ; Humans ; KCNQ1 Potassium Channel ; genetics ; Long QT Syndrome ; genetics ; pathology ; Male ; Middle Aged ; Mutation ; NAV1.5 Voltage-Gated Sodium Channel ; genetics ; Polymorphism, Single Nucleotide ; genetics ; Potassium Channels, Voltage-Gated ; genetics ; Young Adult