Solis-Pazmino, Paola

Background: Preparation for radioiodine (RAI) therapy in differentiated thyroid cancer (DTC) often requires thyroid hormone withdrawal (THW) to achieve thyrotropin (TSH) stimulation. Current guidelines recommend TSH ≥30 mIU/L, a target that prolongs hypothyroidism and worsens quality of life, yet rests on limited evidence. Objective: To evaluate the association between pre-RAI TSH levels and oncologic outcomes in adults with DTC prepared by THW. Methods: We conducted a systematic review and meta-analysis of studies comparing outcomes across pre-RAI TSH thresholds (<30 vs. ≥30, <60 vs. ≥60, and <90 vs. ≥90 mIU/L) in adults with DTC prepared by THW. Primary outcomes included disease-specific mortality, recurrence, and response to therapy. Searches in MEDLINE, Embase, Cochrane, and Scopus (inception to March 2025) identified eligible studies. Risk of bias was assessed using the CLARITY tool and certainty of evidence using GRADE. Pooled relative risks (RRs) were calculated using random-effects models. This systematic review was registered in PROSPERO (CRD42020158354). Results: This meta-analysis included eight retrospective cohort studies comprising a total of 4651 DTC patients, predominantly women (68.5%) with a mean age of 46 years. All patients underwent THW before RAI. Across all TSH thresholds examined (<30, <60, and <90 mIU/L), higher pre-RAI TSH levels were not associated with better treatment response, lower recurrence, or reduced mortality. Specifically, patients with higher pre-RAI TSH levels (≥30 mIU/L) did not have better oncologic outcomes compared with those with lower levels (<30 mIU/L). At 2- and 3-year follow-up, no significant differences were observed in excellent (pooled RR = 0.87; confidence interval [CI] 0.68–1.11) or indeterminate (RR = 1.28; CI 0.72–2.27) response rates. Similarly, recurrence rates did not differ (RR = 1.45; CI 0.83–2.55), and no study demonstrated a difference in disease-specific mortality across follow-up periods extending up to 10 years. The certainty of evidence for all outcomes was rated very low due to risk of bias, heterogeneity, and imprecision. Conclusions: The current evidence base is insufficient to support or refute the routine use of a specific TSH threshold before RAI administration. These findings question the recommendation to achieve TSH ≥30 mIU/L before RAI and highlight the need for trials to define the minimal effective level of TSH stimulation.

Introduction Differentiated thyroid cancer (DTC) is the most common endocrine malignancy, with a high 5-year survival rate of approximately 98%. Despite advances in diagnosis and treatment, up to 20% of patients experience recurrence, adversely affecting their quality of life. Predictive models have been developed to assess recurrence risk and guide clinical decision-making, but these models often face limitations such as retrospective design, lack of diversity in study populations and absence of external validation. The primary aim is to externally validate existing predictive models for DTC recurrence using prospective data from a diverse Latin American cohort. The secondary aim is to explore opportunities for model recalibration to improve their performance in our population. Methods and analysis The CaTaLiNA study is a multicentre prospective observational study conducted across 10 hospitals in five Latin American countries, including Ecuador, Peru, Uruguay and Mexico. Patients aged 18 years or older receiving treatment for DTC, such as the first thyroid surgery, active surveillance or radiofrequency ablation will be included. Recruitment will occur from November 2023 to June 2025, with follow-up extending until June 2028. Data collection will include baseline clinical, surgical and histological characteristics, treatment details and follow-up outcomes. Statistical analysis will follow the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis guidelines, using imputation strategies for missing data and evaluating calibration and discrimination of the prediction models. Calibration measures include the ratio of expected and observed events, calibration slope and calibration plot, while discrimination will be assessed using the C-index and area under the receiver operating characteristic curve. Ethics and dissemination This study protocol was approved by Comité de Ética de Investigación en Seres Humanos de la Universidad San Francisco de Quito USFQ ‘CEISH-USFQ’ APO-010–2023-CEIHS-USFQ Oficio No. 161-2023-CA-23030M-CEISH-USFQ. Results will be disseminated via peer-reviewed publications.

Abstract Primary thyroid lymphoma is a rare thyroid cancer, comprising ˂5% of thyroid neoplasms. Most cases are diffuse large B-cell lymphoma (DLBCL). Coexistence with papillary thyroid cancer (PTC) is extremely rare. This study presents a case of a 55-year-old woman with DLBCL and micropapillary thyroid cancer who underwent lobectomy, chemotherapy, and radiotherapy. Additionally, we performed a systematic review of 10 cases, including the reported case. The risk of bias in case reports varied. DLBCL diagnoses were mainly made after surgery, with total thyroidectomy being the most common surgical procedure. Chemotherapy was administered in most cases, and radiotherapy was used in some cases. Long-term outcomes indicated a low recurrence rate. While some debate the role of surgery in thyroid lymphoma, this study suggests that surgery should be considered in selected cases. Further research is needed to determine optimal treatment strategies for DLBCL with PTC.

Abstract Carotid body tumors (CBTs) are a neoplasm that affects the carotid glomus. This study aims to improve the management of CBTs in Ecuador. This single-center, retrospective observational study was conducted at the Instituto de la Tiroides y Enfermedades de Cabeza y Cuello (ITECC). We included adults with CBTs, between January 2019 and August 2022. A total of 15 patients with CBTs were included. All patients were females living at high altitudes (&gt;2500 m). In the Shamblin classification, 12 tumors were type II, and 3 were type III. Complete tumor resection was performed in all patients without pre-operative embolization. All patients had benign CBTs with a mean follow-up of 17, 73 months. In a time when the medical cost is high mainly in low-income countries such as Ecuador, further investigation should be undertaken in the form of randomized prospective trials to answer who would benefit from the pre-TAE procedure.