A case report of malignant struma ovarii with papillary thyroid carcinoma.

Key clinical message: Struma ovarii (SO), is a rare and specialized ovarian teratoma. The treatment is controversial depending on the risk of recurrence and metastasis. Here a SO with papillary thyroid carcinoma is reported and the approach is thoroughly discussed. Abstract: Struma ovarii (SO) is a highly specialized ovarian teratoma primarily composed of thyroid tissue. Clinical features associated with SO include lower abdominal discomfort, unusual vaginal bleeding, ascites, and hyperthyroidism. While SO rarely transforms into malignancy, the optimal degree of treatment remains controversial due to the varying risks of recurrence and metastasis. In this report, we present the case of a 64-year-old woman experiencing abdominal pain and diagnosed with SO, accompanied by papillary thyroid carcinoma. We thoroughly discuss the evaluation and management of this rare condition.

A Rare Case of Persistent Multifocal Cribriform-Morular Thyroid Carcinoma.

Background/Objective: Cribriform-morular thyroid carcinoma (CMTC) was considered a variant of papillary thyroid carcinoma (PTC) but is a separate entity in the 2022 World Health Organization classification. CMTC has an association with familial adenomatous polyposis (FAP). Our objective is to report a case of CMTC who was subsequently diagnosed with FAP, to highlight these associated entities and implications for management. Case Report: A 15-year-old female with a history of iron-deficiency anemia and alpha-gal syndrome presented with several years of goiter and dysphagia. She also noted unintentional weight loss, abdominal pain, melena and hematochezia, and symptomatic anemia. Physical examination was significant for multiple thyroid nodules. Laboratory results revealed normal thyroid function and iron deficiency. Multiple nodules were visualized on thyroid ultrasound, and fine needle aspiration biopsy was consistent with PTC. Total thyroidectomy was performed with a revised diagnosis of multifocal CMTC, with administration of adjuvant radioactive iodine due to persistent disease. Genetic testing confirmed FAP and she was referred for upper endoscopy, colonoscopy, and an evaluation for colectomy. Discussion: There are no best practice guidelines for management of CMTC. Management of CMTC is guided by FAP status; sporadic cases can be managed with hemithyroidectomy, while FAP-associated cases are better managed with total thyroidectomy. Recurrence is usually managed with surgical resection. The decision to treat with adjuvant radioactive iodine is often extrapolated from management of classic PTC. Conclusion: Thyroid carcinoma in the setting of extensive family history of colorectal carcinoma should arouse suspicion for CMTC. Patients with CMTC should receive a referral for colonoscopy and genetic testing for FAP.

Cardiovascular Health by Graves' Disease Management Modality - Surgery Versus Radioactive Iodine Versus Antithyroid Medications: A Network Meta-Analysis.

INTRODUCTION: Graves' disease is an autoimmune disorder of the thyroid gland associated with the overproduction of thyroid hormones. Excess secretion of thyroid hormones leads to cardiovascular consequences. Treatment options include antithyroid medications (ATM), radioactive iodine (RAI) ablation, and total thyroidectomy. We examined the cardiovascular outcomes following Graves' disease management modality. METHODS: A systematic search was performed up to September 22nd, 2021, using PubMed, EMBASE, and Web of Science databases. We conducted a network meta-analysis analyzing cardiovascular outcomes of interest, including congestive heart failure (CHF), arrhythmia, atrial fibrillation (AF), and hypertension. RESULTS: Three studies were included in this analysis totaling 6700 patients with Graves' disease, of which 74% were female. The mean age was 44.34 y. When compared to pretreatment, management options lowered the risk of maintaining arrhythmia 81% with surgery (relative risk [RR] = 0.19; 95% confidence interval [CI] = 0.12 to 0.31), 67% with ATM (RR = 0.33; 95% CI = 0.23 to 0.49), and 50% with RAI (RR = 0.50; 95% CI = 0.13 to 1.95). Risk of maintaining CHF was reduced 80% with surgery (RR = 0.20; 95% CI = 0.08 to 0.49), 41% with ATM (RR = 0.59; 95%CI = 0.52 to 0.67), and only 7% with RAI (RR = 0.93; 95%CI = 0.68 to 1.26). Treatment-ranking analysis found all parameters, including CHF, arrhythmia, AF, and hypertension, to be in favor of surgical treatment over medical treatment and RAI ablation. CONCLUSIONS: This is the first network meta-analysis analyzing the cardiovascular outcomes in Graves' disease patients by treatment option. Our study demonstrated that surgery is superior to RAI and medical treatment.

Management of malignant struma ovarii: is aggressive therapy justified? Case report and literature review.

BACKGROUND: Struma ovarii (SO) is a rare ovarian teratoma containing predominantly thyroid tissue. In rare situations SO may develop malignancy. Most cases of malignant struma ovarii (MSO) are diagnosed after surgical removal, based on histopathological examination. There are still controversies regarding the extent of surgery and postoperative management in MSO, due to its unpredictable behavior, possible risk of metastasis and relatively high rate of recurrence. CASE PRESENTATION: We present the case of a patient diagnosed with a right ovarian cyst discovered incidentally during routine ultrasound examination. Its rapid growth and pelvic MRI raised the suspicion of a neoplastic process. She underwent total hysterectomy and bilateral adnexectomy. The anatomopathological diagnosis was MSO with follicular variant of papillary thyroid carcinoma. Prophylactic total thyroidectomy was performed, followed by radioactive iodine ablation (RAI), and suppressive therapy with levothyroxine. At 1 year follow-up, the patient was disease free. CONCLUSIONS: Even if latest literature reports consider that completion of local surgery with total thyroidectomy and RAI might be too aggressive in cases of MSO without extraovarian extension, in our case it was decided to follow the protocol for primary thyroid carcinoma, in order to reduce the recurrence risk.

Methimazole Desensitization in a 4-Year-Old With Refractory Graves Disease.

OBJECTIVE: To describe a 4-year-old girl with Graves disease and methimazole allergy who underwent desensitization, allowing continued methimazole use when other treatments were contraindicated. METHODS: We formulated a desensitization plan utilizing cetirizine and prednisone for a patient with previously diagnosed Graves disease who developed urticaria and arthralgias from methimazole. She was admitted for monitoring of rash, urticaria, angioedema, and anaphylaxis. Her methimazole dose was increased as tolerated and then titrated as an outpatient. RESULTS: A 4-year-old girl presented with a heart rate of 195 beats/minute, blood pressure of 145/108, and subsequent labs of undetectable thyroid stimulating hormone (TSH), free T4 5.8 ng/dL, thyroid peroxidase antibody 11.5 IU/ml, and TSH receptor antibody 39.03 IU/L, consistent with Graves disease. She developed urticaria and arthralgias after 2.5 weeks on methimazole, which resolved with drug cessation. Because of her age, the risks of radioactive iodine ablation and surgery were concerning; therefore, methimazole desensitization was attempted. Prednisone (1 mg/kg/day) and cetirizine (5 mg/day) were started prior to low-dose methimazole reintroduction and continued for 7 days. Methimazole was then gradually increased to a final dose of 15 mg daily (0.8 mg/kg/day). Free T4 normalized within a month (1.12 ng/dL), and her TSH normalized within 10 months (4.61 mcU/mL). Except for 2 possible breakthrough allergic responses that resolved with pulse steroids, she continues to tolerate methimazole. CONCLUSION: We describe a case of methimazole desensitization. In this patient, pretreatment with prednisone, coupled with daily cetirizine, successfully induced methimazole tolerance when other treatment modalities were contraindicated.

Clinical Case Report: Dissociation of Clinical Course of Coexisting Autoimmune Hepatitis and Graves Disease.

OBJECTIVE: Concurrent autoimmune disorders, including autoimmune hepatitis (AIH), with Graves disease have been reported. Glucocorticoids can simultaneously lower thyroid hormone levels and treat AIH. Recurrence of hyperthyroidism is associated with recurrence of hepatitis. We present a case of coexisting AIH and Graves thyrotoxicosis, which improved with prednisone, but the thyrotoxicosis recurred during a prednisone taper while the hepatitis stayed in remission. METHODS: Evaluation included measurements of liver enzyme levels, thyroid function tests, and thyroid-stimulating antibodies as well as abdominal ultrasound, magnetic resonance imaging, and liver biopsy. RESULTS: A 47-year-old woman presented with nausea and jaundice. Workup showed an aspartate aminotransferase level of 1956 (reference, 10-42) U/L and alanine aminotransferase level of 1634 (reference, 14-54) IU/L. The liver biopsy was consistent with AIH. Nine months later, she reported palpitations, heat intolerance, and weight loss and was diagnosed with Graves disease. The patient received prednisone at 60 mg daily, and the liver and thyroid functions normalized after 1 month. Prednisone was tapered to 5 mg daily. Seven months later, she presented with a thyroid-stimulating hormone level of 0.049 (reference, 0.340-5.6) µIU/mL) and free thyroxine level of 3.96 (reference, 0.58-1.64) ng/dL. Liver enzymes remained at normal levels. Prednisone was increased from 5 to 20 mg to treat hyperthyroidism. The patient was referred for thyroidectomy for a diagnosis of Graves disease with thyrotoxicosis. CONCLUSION: This case is an example of coexisting autoimmune diseases, Graves disease and AIH, with different clinical courses. Despite initial resolution with glucocorticoid therapy, Graves disease recurred, while AIH stayed in remission.

Prophylactic central lymph node dissection informs the decision of radioactive iodine ablation in papillary thyroid cancer.

BACKGROUND: Prophylactic central lymph node dissection (CLND) in papillary thyroid cancer (PTC) is controversial. We aimed to investigate if prophylactic CLND aids risk stratification and contributes to the decision for postoperative RAI ablation. METHODS: Patients undergoing thyroidectomy for PTC and prophylactic CLND were identified from an endocrine surgical unit database. Pathology reports where reviewed for number and size of lymph nodes and patients stratified by risk according to the ATA guidelines. RESULTS: 426 patients were identified with PTC ≤4 cm and prophylactic CLND. 96 patients (23%) had central lymph node metastasis (CLNM) that qualified them for the intermediate risk group. In 17 patients (4%), the CLNM data led to upgrading independently of other histopathological characteristics. Correcting for multiple variables, CLNM was an independent factor contributing to RAI treatment. CONCLUSION: Prophylactic CLND provides information to aid the selection of RAI ablation independent of primary cancer histology for risk stratification in 4% of patients. This benefit should be carefully balanced with the risk of CLND and patient treatment choice when deciding on management of PTC ≤4 cm.

Preablation Diagnostic Whole-Body Scan vs Empiric Radioactive Iodine Ablation in Differentiated Thyroid Cancer: Cost-effectiveness Analysis.

OBJECTIVE: To perform a comparative analysis of postthyroidectomy radioactive iodine ablation dosing with or without the implementation of a diagnostic whole-body scan in patients with well-differentiated thyroid cancer. STUDY DESIGN: Decision analysis model. SETTING: Hospital or ambulatory center. METHODS: A decision tree model was created to determine the cost-effectiveness of radioactive iodine ablation dosed with diagnostic whole-body scans versus empiric radioactive iodine ablation in patients with differentiated thyroid cancer undergoing postthyroidectomy ablation. The decision tree was populated with values from the published literature. Costs were represented by 2020 Medicare reimbursement rates (US dollars), and morbidity and survival data were used to calculate quality-adjusted life-years. The incremental cost-effectiveness ratio was the primary outcome. RESULTS: Empiric radioactive iodine dosing was the dominant economic strategy, producing 0.94 more quality-adjusted life-years while costing $1250.07 less than management with a diagnostic whole-body scan. Sensitivity analyses upheld these results except in cases involving a large discrepancy in successful ablation rates between the diagnostic and empiric treatment arms. CONCLUSION: For patients with differentiated thyroid cancer requiring postthyroidectomy ablation, it is more cost-effective to administer radioactive iodine empirically.

Cardiovascular Outcomes of Thyroidectomy or Radioactive Iodine Ablation for Graves' Disease.

BACKGROUND: Treatment options for Graves' disease (GD) include medical management with antithyroid medications, radioactive iodine (RAI) ablation, or total thyroidectomy (TT). Definitive treatment with RAI ablation may be associated with worse cardiovascular morbidity and mortality than TT. We sought to determine the rate of cardiovascular morbidity before and after definitive treatment for GD. METHODS: This study is a retrospective single-institution study of sequential adult patients with GD from 2012 to 2018 treated with RAI ablation or TT. Patients with prior thyroid surgery or RAI ablation with subsequent thyroidectomy were excluded. Demographic and clinical variables were collected from diagnosis of GD to last follow-up. Data analysis was performed with descriptive statistics, univariate analysis with Fisher's exact test for categorical variables and the Mann-Whitney U test for continuous variables. RESULTS: One-hundred and eighty-four patients underwent definitive treatment for GD during the study period, of which 164 met inclusion criteria. One hundred and ten patients (67%) in the study group had TT and 54 (33%) had RAI ablation with a mean dose of 18.4 mCi (standard deviation 6.1). There were no differences in clinical or demographic factors in patients undergoing RAI ablation versus TT for definitive treatment including age, sex, thyroid-stimulating hormone level, free thyroxine level, or thyroid-stimulating immunoglobulin level at time of diagnosis, nor was there any difference in pretreatment cardiovascular comorbidity. Patients with TT had higher rates of resolution of arrhythmia after treatment than those undergoing RAI ablation, P = 0.02. There were no differences in treatment-related complications between the groups. CONCLUSIONS: For patients undergoing definitive treatment for GD, TT is associated with improved rate of resolution of cardiac arrhythmia compared with RAI ablation.

Longer-term recurrence rate after low versus high dose radioiodine ablation for differentiated thyroid Cancer in low and intermediate risk patients: a meta-analysis.

BACKGROUND: Regarding the longer-term recurrence rate the optimal activity for the remnant thyroid ablation in patients with differentiated thyroid cancer (DTC) is discussed controversially. For the short-term ablation success rate up to 12 months there are already several meta-analyses. In this study we performed the first meta-analysis regarding the longer-term recurrence rate after radioactive 131-I administration. METHODS: We conducted an electronic search using PubMed/MEDLINE, EMBASE and the Cochrane Library. All randomized controlled trials (RCTs) assessed the recurrence rate after radioactive iodine ablation in patients with DTC, with a follow-up of at least two years were selected. Statistics were performed by using Review Manager version 5.3 and Stata software. RESULTS: Four RCTs were included in the study, involving 1501 patients. There was no indication for heterogeneity (I2 = 0%) and publication bias. The recurrence rate among patients who had a low dose 131-iodine ablation was not higher than for a high dose activity (odds ratio (OR) 0.93 [95% confidence interval (CI) 0.53-1.63]; P = 0.79). The mean follow-up time was between 4.25 and 10 years. The subgroup analysis regarding the TSH stimulated thyroglobulin values (< 10 ng/mL versus < 2 ng/mL versus ≤1 ng/mL) showed no influence on recurrence rate. CONCLUSIONS: For the first time we showed that the longer-term, at least 2-year follow-up, recurrence rate among patients who had 131-iodine ablation with 1.1 GBq was not higher than with 3.7 GBq.

Prevalence and Features of Thyroglossal Duct Cyst on Ultrasonography, According to Radioactive Iodine Therapy: A Single-Center Study.

Objective: The relationship between radioactive iodine therapy (RIT) and prevalence of thyroglossal duct cysts (TGDC) on ultrasonography (US) has not been reported. We assessed the prevalence and US features of TGDC according to RIT. Methods: From July 2017 to June 2018, 3,146 subjects underwent thyroid or neck US at our center. The presence or absence of TGDCs was prospectively investigated based on real-time US examination. Among the 3,146 subjects, 261 subjects were excluded because of <18 years of age, unclear information of RIT, or the presence of a radiation therapy history to the neck. Eventually, 2,885 subjects were included in this study. Results: Of the 2,885 subjects finally included, 126 (4.4%) showed a TGDC on US. Those with RIT history showed a higher prevalence of TGDCs than those without (no statistical difference, p = 0.062). In 697 male subjects, there were statistical differences in type of surgery, RIT history, and session number of RIT between those with or without TGDCs (p < 0.0001). In 126 subjects with TGDCs, only sex showed a significant difference between those with or without RIT history (p = 0.015). However, there were no significant differences in the location, size, and shape of TGDCs (p > 0.05). The common US features of TGDC were suprahyoid location, ~1 centimeter, and flat-to-ovoid or round shape. Conclusions: RIT may increase the prevalence of TGDCs, particularly in men.

Referral Practice for Radioactive Iodine Ablation (RAI) after ATA guidelines 2015: results from a Tertiary Cancer Care Centre.

INTRODUCTION: The ATA guidelines for differentiated thyroid cancer (DTC) are one of the most widely referred to. Their 2015 edition proposed a new risk stratification system and modified the indications for radioactive iodine (RAI) ablation especially for the low risk category. We attempted to analyze whether the new guidelines altered referral practices for RAI ablation at our institute. METHODOLOGY: Patients who underwent total or completion thyroidectomy for DTC during 2016-2017 were included. Relevant demographical and pathological data was tabulated. Patients were classified as per the new stratification system and referral practice for RAI ablation documented. RESULTS: 238 patients were included. Of these 20.6% were low risk, 44.1% were intermediate and 35.3% were high risk as per modified guidelines. All patients within the intermediate and high-risk group and 77.8% of the low risk group were referred for RAI ablation. Analysis of risk factors revealed that within the low risk group there were three patients with < 5 metastatic nodes, all within 3 cm in size-a category that the ATA failed to stratify appropriately. Among those labeled as Intermediate risk due to microscopic extra thyroidal extension (ETE), 85% had no other risk factors and were upstaged solely due to microscopic ETE, which is interestingly no longer included in the TNM staging. CONCLUSION: Majority of low risk patients continue to receive RAI ablation due to persistent belief emanating from literature that remnant ablation improves outcomes and aids in follow up. The issue of RAI ablation for low risk group and prognostic implications of microscopic ETE and limited nodal disease need to be revisited.

Comparison Between the Treatment Modalities for Graves' Disease at King Abdulaziz Medical City, Jeddah.

Background Graves' disease is the most common cause of thyrotoxicosis. It can be treated using three different modalities, which include anti-thyroid drugs (ATD), radioactive iodine (RAI), and near-total thyroidectomy. This cohort study aimed to assess the treatment modality preferred at King Abdulaziz Medical City (KAMC) and to compare the treatment options in relation to the prognosis of the disease. Methods A retrospective cohort study was conducted on a total of 100 patients with Graves' disease who were treated and followed up in the endocrine clinics at KAMC between January 2013 and December 2018. Data on age at diagnosis, duration of illness, treatment modality, and response to treatment were extracted from paper and electronic medical files and analyzed. Results A total of 100 patients with Graves' disease were included in this cohort study. The ratio of female:male was 2:1. The median age in years was 32 (16). They were treated with ATD (60%), RAI ablation (40%), and none were treated by surgery. The remission rate was 53.3% for patients treated with ATD and 95% for RAI ablation. Hypothyroidism occurred in 90% of the responders to RAI and in 12% that were treated with ATD. Most of the patients that relapsed underwent RAI as the second line of treatment. Their remission rate was 78.6%. Conclusion ATD was the treatment modality mostly used for Graves' disease in our center. It resulted in a remission rate of 53%, which is higher than reported in national studies. Although the rate of remission post RAI ablation was as high as 95%, most patients developed hypothyroidism.

Radioactive iodine ablation post differentiated thyroid cancer surgery: an analysis of use and impact of the American Thyroid Association guidelines.

BACKGROUND: The 2009 American Thyroid Association (ATA) three-tiered risk stratification, and its updated version in 2015, provided clearer guidance on the use of radioactive iodine (RAI) ablation in differentiated thyroid cancer (DTC) patients. This study examines the impact of these guidelines on RAI use in our institution. METHODS: Patients diagnosed with DTC during three different time periods (group 1: 2002-2006, group 2: 2010-2014 and group 3: 2017-2018) were identified and risk stratified according to the ATA guidelines. RAI use and extent of surgery were compared between the three groups. Categorical variables were analysed using Fisher's exact (2 × 2) and chi-squared (>2 × 2) tests. RESULTS: A total of 415 patients were included (group 1 = 88, group 2 = 215, group 3 = 112). The proportion of patients having total thyroidectomy were 84.6, 84.7 and 69.6% in groups 1, 2 and 3, respectively (P = 0.003). Central lymph node dissection was significantly higher in the more contemporary groups compared to group 1 (9.1 versus 41.9 versus 64.3%, P < 0.001). Overall, fewer patients received RAI in more recent times (76.6 versus 54.8 versus 26.8%, P < 0.001), most evident in the low-risk patients (70 versus 29.1 versus 5.1%, P < 0.001). In the high risk group, the majority received RAI, with no difference between the groups. CONCLUSION: Comparing DTC patients treated in our unit before and after publications of the 2009 and 2015 ATA guidelines, more nodal surgery was performed with less RAI administered in the latter groups. Better risk stratification according to the ATA guidelines has allowed more judicious use of RAI ablation.

Is hemi-thyroidectomy adequate in low risk differentiated thyroid cancer?

In low-risk differentiated thyroid carcinoma (LRDTC), appropriate surgical procedure in terms of hemi/total thyroidectomy (TT) has been an area of debate. The aim was to determine whether in LRDTC patients, hemithyroidectomy would be an adequate treatment, determine incidence of disease in contralateral lobe and evaluate the effect of radioactive iodine ablation (RAIA). Retrospective study was done from 2008 to 2014 at a single institution. Preoperative ultrasound (USG) and histopathology reports of all LRDTC patients following total/completion thyroidectomy were recorded. Details of postthyroidectomy, thyroid whole body scan, and stimulated serum thyroglobulin (sTg) levels were also documented and results analyzed. A total of 114/562 patients met inclusion criteria. Of these, 25/114 (22%) underwent hemithyroidectomy followed by a completion thyroidectomy while remaining 89/114 (78%) underwent TT initially. Preoperative USG detected single-lobe involvement in 44 patients; however, among them, histopathology revealed bilateral lobe disease in 17 (38.6%). There was a significant fall of sTg level following RAIA as compared to that before RAIA in T1b-T2 (P = 0.009 and 0.012, respectively). Median follow-up was 2 years (range: 1-7 years) with no distant metastasis or deaths recorded till 2017, except for one local recurrence 4 years after RAIA. In conclusion, the role of TT in LRDTC patients is important as 46% of patients were found to have tumor in contralateral lobe as well. Significant fall in sTg levels following RAIA justifies RAIA of remnant lobe even in LRDTC (T > 1a). It facilitates early detection of recurrence when sTg alone is used for follow-up.

Surgical management of pediatric thyroid disease: Complication rates after thyroidectomy at the Children's Hospital of Philadelphia high-volume Pediatric Thyroid Center.

BACKGROUND: Recent studies suggest improved outcomes for children undergoing thyroidectomy at high-volume pediatric surgery centers. We present outcomes after thyroid surgery at a single center and advocate for referral to high-volume centers for multidisciplinary management of these children. METHODS: Medical records were reviewed for all pediatric patients undergoing thyroid surgery at a single institution from 2009 through 2017. Routine recurrent laryngeal nerve and parathyroid hormone monitoring was used. Lymph node dissections were performed in appropriately selected cancer patients. Data collection focused on pathologic diagnosis, surgical technique, and surgical complications, including postoperative hematoma, neurapraxia, permanent nerve damage, hypocalcemia, and transient and permanent hypoparathyroidism. RESULTS: From 2009 through 2017, 464 patients underwent thyroid surgery. Median age of the cohort was 15 years (range 2-24). Thirty-three percent were diagnosed with benign nodules (n=151), 36% with papillary or follicular thyroid cancer (n=168), 27% with Graves' disease (n=124), 3% with medullary thyroid cancer (n=14), and 1.5% underwent prophylactic thyroidectomy for MEN2a (n=7). Six patients required return to the OR for hematoma evacuation including 5 patients after surgery for Graves' disease (RR 8.7, 95% CI 1.06-71.85). In sixteen cases, concern about neurapraxia resulted in laryngoscopy, revealing eleven patients with vocal cord paresis. Two of these patients demonstrated a persistent deficit at 6 months postoperatively (0.4%). Thirty-seven percent of patients had transient hypoparathyroidism (n=137), and two patients had persistent hypoparathyroidism 6 months after total thyroidectomy (0.6%). There was no significant difference in either hypocalcemia or hypoparathyroidism after total thyroidectomy based on age or diagnosis. CONCLUSIONS: Characterizing outcomes for pediatric patients based on diagnosis will assist in preoperative counseling for patients and their families. This high-volume center reports low complication rates after pediatric thyroid surgery, highlighting that referral to high-volume centers should be considered for children and adolescents with thyroid disease requiring surgery. LEVEL OF EVIDENCE: Level IV.

Time trends of thyroglobulin antibody in ablated papillary thyroid carcinoma patients: Can we predict the rate of negative conversion?

OBJECTIVES: Persistence of thyroglobulin antibody (TgAb) in patients with papillary thyroid carcinoma (PTC) years after total thyroidectomy (TT) followed by ablation occurs even without any evidence of structural disease. Few studies have studied the natural course of TgAb positivity and factors that may influence this course. The present study evaluated the time trends of TgAb in ablated PTC patients and aimed to identify the predictive factors for the rate of negative conversion of TgAb. MATERIALS AND METHODS: Overall, 1279 patients who underwent TT and subsequent ablation for PTC, with available data on thyroid peroxidase Ab (TPOAb) and TgAb prior to surgery (preop-) and ablation (abl-) were enrolled. Patients with initial distant metastasis or recurrence during follow-up were excluded. RESULTS AND CONCLUSION: Preop-TgAb was positive in 24.9% of patients (n = 319), whereas abl-TgAb positivity decreased to 12.8% (n = 164). In 164 patients positive for abl-TgAb, TgAb in patients with higher abl-TgAb levels decreased more gradually than those observed in patients with lower abl-TgAb levels (p < 0.001). Furthermore, in patients within the same range of abl-TgAb levels, patients positive for abl-TPOAb had a higher rate of negative conversion of TgAb compared with negative patients for abl-TPOAb (log rank p < 0.001). TPOAb significantly increased the rate of negative conversion in multivariate analysis adjusted for abl-TgAb (odds ratio 1.59, 95% confidence interval 1.11-2.28, p = 0.011). This study clearly showed that abl-TgAb titers and abl-TPOAb status can predict the rate of negative conversion. These findings can guide the optimal timing for additional examination in patients positive for TgAb during follow-up.

La respuesta excelente al tratamiento en pacientes con cáncer diferenciado de tiroides se mantiene a lo largo del seguimiento independientemente del riesgo de recurrencia inicial / Excellent response to treatment in patients with differentiated thyroid cancer is maintained throughout follow-up regardless of the risk of initial recurrence

Resumen Introducción: El riesgo de recurrencia en cáncer diferenciado de tiroides (CDT) se utiliza para determinar la frecuencia de las respuestas estructurales incompletas o excelentes con un valor predictivo positivo cercano al 30%. El riesgo dinámico, que evalúa la respuesta inicial al tratamiento demostró tener una proporción de varianza explicada de hasta el 80%. Por otro lado, en nuestro medio es fácil establecer la respuesta inicial, pero muchas veces es dificultoso determinar el riesgo de recurrencia desde donde partió el paciente. A esto hemos denominado "la silla rota" en pacientes con CDT. Materiales y métodos: Se realizó el análisis retrospectivo incluyendo 340 pacientes con los siguientes criterios:1) edad ≥18 años al momento del diagnóstico, 2) tratamiento inicial con tiroidectomía total y ablación con radioyodo, 3) seguimiento mínimo ≥3 años (excepto si ocurrió metástasis a distancia o muerte antes de ese tiempo), 4) datos anatomopatológicos y estudios complementarios suficientes para poder determinar tanto el riesgo de recurrencia como la respuesta inicial (evaluada en los primeros 6 meses a 2 años de seguimiento) y el estado al final del seguimiento (al momento de la última consulta). Objetivos: Describir la evolución de la respuesta inicial al final del seguimiento para demostrar que esta es la definición más importante, independientemente del riesgo de recurrencia al diagnóstico en pacientes con CDT. Resultados: El 36% de los pacientes presentó una respuesta excelente al tratamiento inicial (n=122) y de ellos, ninguno presentó evidencia estructural de enfermedad al final del seguimiento, independientemente del RR inicial. Conclusiones: La denominada "silla rota" parecería "repararse" correctamente cuando el paciente presenta una respuesta excelente al tratamiento, ya que esta se mantiene al final del seguimiento independientemente del RR inicial. La carencia de un correcto RR inicial no parecería ser imprescindible en pacientes con respuestas excelentes al tratamiento.

ABSTRACT Background: The risk of recurrence (RR) stratification system has been proposed as a useful tool for stablishing the frequency of the structural incomplete and excellent response-to-treatment in patients with differentiated thyroid cancer (DTC). However, the available information at diagnosis could be insufficient to accurately determine the initial RR. We called this situation "the broken chair". Although many studies have shown that the initial response to treatment usually predicts the final outcome, it is not clear if the final outcome could be different in the distinctive responses to treatment, if we analyze it together with the initial RR. Purpose: To investigate the outcomes of patients by comparing both situations: the initial RR and the initial response to treatment with the final outcome to establish if there was a different frequency of structural incomplete response at the end of follow-up. Methods: Retrospective review of 340 DTC patients followed up for at least 3 years after initial total thyroidectomy and radioactive iodine ablation (RAI). We assessed the initial response as the best response to therapy during the first 2 years, and the final response to therapy as the status at the end of follow-up, according to the definitions of the 2015 ATA guidelines. Conclusions: An excellent response to treatment during the first two years of follow-up can fix the "broken chair" in patients treated with DTC who received remnant ablation and it is independent of the initial RR. Results: None of the patients that achieved an initial excellent response to treatment (n=122, 36%), showed structural evidence of disease in the entire follow-up despite their initial RR.

Determining patient selection tool and response predictor for outpatient 30 mCi radioiodine ablation dose in non-metastatic differentiated thyroid carcinoma: a Japanese perspective.

The lack of isolation ward throughout Japan has long been limiting the 131I radioactive iodine (RAI) ablation for differentiated thyroid cancer (DTC) cases. The 30 mCi RAI ablation was only recently permitted for outpatient basis. However, no patient selection tool nor response predictor has been proposed. This study evaluated factors to find response predictor and determinant for the suitable patients. The retrospective study reviewed 47 eligible non-metastatic papillary DTC patients whose had first 30 mCi RAI ablation after total thyroidectomy. Age, gender, clinical stage, risk category, and pre-ablation serum thyroglobulin (Tg) level were among covariates analyzed to determine the patient selection factors; while the thyroid bed uptake on initial whole body scan (WBS) was later also included in determining RAI ablation response. Thirteen (28%) patients had a low risk (T1-2) while 23 (49%) and 11 (23%) had an intermediate (T3) or high risk (T4), respectively. Twenty-five patients were responders, and 22 were non-responders. All factors were similar between responders and non-responders except pre-ablation serum Tg level (p < 0.001). In multivariate analysis, pre-ablation serum Tg level was the only significant factor for both patient selection (odd ratio (OR) = 1.52, 95% confidence interval (CI) = 1.13-2.06) and response predictor (OR = 1.48; 95% CI = 1.12-1.95). With the cut-off of 5.4 ng/mL, pre-ablation serum Tg level predicts RAI ablation response with 92% specificity and 73% sensitivity. Pre-ablation serum Tg level may help patient selection and predict the response to outpatient 30 mCi RAI ablation among post total thyroidectomy non-metastatic DTC patients.

Computed tomography features of the major salivary glands after radioactive iodine ablation in patients with papillary thyroid carcinoma.

OBJECTIVE: No previous study has investigated computed tomography (CT) features of the major salivary glands (MSGs) after postoperative radioactive iodine ablation (RIA). This study aimed to assess CT features of the MSGs after RIA in patients with papillary thyroid carcinoma (PTC). METHODS: The study population comprised consecutively registered PTC patients who had undergone total thyroidectomy, RIA, follow-up neck ultrasonography (US), and neck CT. The US and CT features of the parotid and submandibular glands in each patient were retrospectively evaluated by a single radiologist. Post-RIA changes were determined by comparisons between follow-up neck US results (main reference) and between preoperative and post-RIA neck CT features. RESULTS: Of the 28 patients, 13 (46.4%) showed post-RIA changes in the parotid glands (n = 8), submandibular glands (n = 0), or both (n = 5) on neck CT. Of the 56 MSGs in 28 patients, post-RIA changes were more common in the parotid glands (n = 23, 41.1%) than in the submandibular glands (n = 8, 14.3%). The common CT findings of post-RIA changes in the parotid gland included low parenchymal attenuation, decreased glandular size, a lobulated margin, decreased or increased parenchymal enhancement, and an inhomogeneous enhancement pattern, whereas common CT findings of post-RIA changes in the submandibular gland included decreased glandular size, a lobulated margin, iso-enhancement, and an inhomogeneous enhancement pattern. CONCLUSION: The common CT features of post-RIA changes in MSGs include decreased glandular size, a lobulated margin, and an inhomogeneous enhancement pattern.