Radioiodine (131I) treatment decision-making for low- and intermediate-risk differentiated thyroid cancer

ABSTRACT Objective: The purpose of this study was to investigate the effect and influencing factors of post-surgical radioactive iodine (RAI) therapy for patients with low- and intermediate-risk differentiated thyroid cancer (DTC). Subjects and methods: A retrospective analysis of 423 low- and intermediate-risk DTC patients admitted to the Department of Nuclear Medicine, Sichuan Provincial People's Hospital from January 2005 to December 2020 was performed. All patients were treated with surgery, had a postoperative pathological diagnosis, and were treated with RAI, including 89 males and 334 females. Recurrence risk stratification: 143 cases were low-risk, and 280 cases were intermediate-risk. Results: The excellent response (ER) rate for low- and intermediate-risk were 93.7% and 78.2%, respectively (P < 0.05). There were significant differences in age, cumulative dose of [131I], and pretreatment stimulated-Tg (pre-Tg) levels between the low- and intermediate-risk groups (P < 0.05). There were significant differences in the cumulative dose of 131I and pre-Tg levels between ER and the non-ER group (P < 0.05). The area under the curve (AUC) values were 0.799 in the low-risk group, and 0.747 in the intermediate-risk group for the ROC curve by ER status of pre-Tg. The ER rate with RAI treatment decreased with an increase in pre-Tg levels. Conclusion: Pre-Tg was an important factor for RAI treatment decision-making and prognostic evaluation and differed between low-risk and intermediate-risk DTC. Aggressive RAI therapy was recommended for low-risk DTC with pre-Tg ≥ 20.0 ng/mL and in intermediate-risk group with pre-Tg ≥ 10.0 ng/mL.

Efficacy of methimazole before the administration of radioactive iodine in the management of Graves' disease: a systematic review and meta-analysis

ABSTRACT BACKGROUND: The efficacy of anti-thyroid drugs in conjunction with radioactive iodine therapy in the management of Graves' disease is still controversial. OBJECTIVE: To compare the efficacy of pretreatment with methimazole before the administration of radioactive iodine for the treatment of Graves' disease. DESIGN AND SETTING: A systematic review and meta-analysis was conducted at a teaching/tertiary hospital in Ibadan, Nigeria. METHODS: A systematic search of the PubMed, Embase, Cochrane Library, and Web of Science databases was performed from inception to December, 2021. RESULTS: Five studies with 297 participants were included. There was no difference in the risk of persistent hyperthyroidism when radioactive iodine was used in conjunction with methimazole compared with when radioactive iodine was used alone (relative risk: 1.02, 95% confidence interval, CI: 0.62-1.66; P = 0.95, I2 = 0%). Subgroup analysis based on the duration between discontinuation of methimazole and the administration of radioactive iodine showed a lower risk of persistent hyperthyroidism when methimazole was discontinued within 7 days before radioactive iodine use, although this did not reach statistical significance (risk ratio: 0.85, CI: 0.28-2.58). CONCLUSIONS: The use of methimazole before radioactive iodine administration was not associated with an increased risk of persistent hyperthyroidism. Concerns about medication toxicity and adverse effects should be considered when clinicians make decisions on combination therapies for the treatment of Graves' disease. PROSPERO REGISTRATION: CRD42020150013, https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=150013.

New-onset thyroid eye disease after COVID-19 vaccination in a radioactive iodine-treated graves’ disease patient: A case report and literature review / Journal of the ASEAN Federation of Endocrine Societies

@#Autoimmunity associated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been well-described as the mechanism of development of thyroid dysfunction following Coronavirus Disease 19 (COVID-19) infection and SARS-CoV-2 vaccination. However, the occurrence of thyroid eye disease (TED) after SARS-CoV-2 vaccination is scarcely described. The postulated mechanisms include immune reactivation, molecular mimicry and the autoimmune/inflammatory syndrome induced by adjuvants (ASIA). We report a case of new-onset TED after receiving the SARSCoV- 2 vaccine.

Early versus delayed post-therapy whole body scintigraphy for well-differentiated thyroid carcinoma: A meta-analysis

Introduction@#No clear consensus exists as to the optimal timing for conducting whole body scintigraphy (WBS) after radioactive iodine (RAI) therapy for differentiated thyroid carcinoma. @*Objective@#This study aimed to compare the utility of early versus delayed post-therapy WBS in identifying residual lesions and metastases.@*Methods@#A systematic review of existing literature was done, yielding 6 observational studies relevant to the subject. Meta-analyses were done comparing lesion detecting rates of early (3-4 days post-RAI) and delayed (7-11 days post-RAI) post-therapy WBS for thyroid remnants and metastases in the lymph nodes, lungs, and bone using a random-effects model with odds ratios (OR) and 95% confidence intervals (CIs). A subgroup analysis was also done relating to the type of collimator used in imaging.

Effects of discontinuation of levothyroxine sodium before radioactive iodine therapy after DTC on blood lipids and renal function in patients / 中华内分泌外科杂志

Objective:To investigate the effect of levothyroxine withdrawal before radioiodine therapy on blood lipids and renal function in patients with differentiated thyroid carcinoma (DTC) after operation.Methods:From Mar. 2020 to Apr. 2022, 214 patients with differentiated thyroid cancer were enrolled in the General Surgery Department, Linyi Central Hospital, Shandong Province. All patients stopped taking levothyroxine sodium after total thyroidectomy. The thyroid function index, blood lipid index and renal function index were measured and compared before and after drug withdrawal (before operation) and after drug withdrawal (before radioiodine treatment). The patients were divided into groups according to the duration of drug withdrawal (drug withdrawal group for 3 weeks, drug withdrawal group for 4 weeks), and the differences of thyroid function index, blood lipid index, and renal function index among patients with different drug withdrawal time were compared. The measurement data in accordance with normal distribution were compared between groups, and independent sample t-test was performed. Results:The levels of free thyroxin T4 (FT 4) and free triiodothyronine (FT 3) in DTC patients decreased significantly ( t=57.60, 71.74,all P<0.001), and the levels of thyroid-stimulating hormone (TSH) increased significantly ( t=102.15, P<0.001). After drug withdrawal, the serum lipid index [triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL), low density lipoprotein (LDL) ] and renal function index [blood urea nitrogen (BUN), serum creatinine (SCR) ] of DTC patients increased significantly ( t=20.17, 42.50, 12.13, 30.73, 16.09, 43.73, all P<0.001). The levels of FT 3 and FT 4 in the 4-week group were significantly lower than those in the 3-week group ( t=7.75 and 10.07, both P<0.001), and TSH was significantly higher than that in the 3-week group ( t=26.46, P<0.001). The levels of TG, LDL, HDL, TC, BUN and Scr in the 4-week group were significantly higher than those in the 3-week group ( t=10.13, 10.29, 8.53, 11.47, 10.54, 8.55, all P<0.001). Correlation analysis showed that the levels of FT 3 and FT 4 in DCT patients were negatively correlated with the levels of TG, LDL, HDL, TC, BUN and Scr ( r=-0.256, -0.189, -0.249, -0.314, -0.352, -0.231, -0.342, -0.259, -0.304, -0.216, -0.391, -0.271, P=0.011, 0.029, 0.007, 0.004, 0.015, 0.036, 0.002, 0.009, 0.019, 0.017, 0.016, 0.003), and the levels of TSH were correlated with TG, LDL, HDL, TC and BUN Scr level was positively correlated ( r=0.257, 0.308, 0.219, 0.311, 0.251, 0.271, P=0.006, 0.013, 0.032, 0.004, 0.006, 0.014) . Conclusion:Stopping levothyroxine sodium before radioactive iodine treatment after DTC can easily lead to dyslipidemia and decreased renal function in patients, and the longer the withdrawal time is, the more obvious the changes of blood lipids and renal function in patients, and the withdrawal time should be shortened in clinical treatment.

Factors influencing changes in total radioactivity in differentiated thyroid cancer patients after 131I treatment / 中华放射医学与防护杂志

Objective:To investigate the changes in total radioactivity in patient body with differentiated thyroid carcinoma (DTC) after 131I treatment and the factors influencing its metabolism. Methods:The clinical data from 218 patients after DTC treatment in the Department of Nuclear Medicine, the Second Affiliated Hospital of Air Force Medical University from September 2021 to April 2022 were retrospectively analyzed. Based on administrated 131I dose, 171 patients were divided into low-dose group (≤ 3.7 GBq) and 47 into high-dose group (>3.7 GBq) . A whole body dynamic radiation monitoring system was used to measure the in vivo residual activity of 131I 24, 48 and 72 h after 131I administration and to explore their influencing factors. Results:24, 48 and 72 h after adimination of 131I, the residual activity of 131I in the low-dose group patients was significantly lower than in the high-dose group patients ( t= -7.46, -3.31, -2.01, P<0.05) . The discharge compliance rate at 24 and 48 h in the low-dose group was significantly higher than that in the high-dose group (21.0% vs. 4.3%, 98.2% vs. 89.4%, χ2 = 7.23, 5.91, P<0.05) , and all patients could meet the discharge criteria at 72 h. Univariate analysis showed that the residual 131I activity at 24 and 48 h was dependent on age, body mass index (BMI) , basal metabolism rate (BMR) and thyroid stimulating hormone (TSH) . As have been shown by multiple linear regression analysis, in the low-dose group, the older age, the higher BMR and the higher TSH level at 24 h tended to the higher 131I residual activity in the body. At 48 h, the higher BMI and the higher TSH level lead to the higher 131I residual activity in patient body. Meanwhile, in the high-dose group, the higher age and BMR at 24 h, tended to the higher in vivo131I residual activity. The influencing factors were analyzed in terms that 131I residual activity reaching 400 MBq in patient body at 24 and 36 h. The result showed that at 24 h the lower TSH level leaded to the lower 131I residual activity in patient body. At 36 h, the younger age, the lower TSH level, and the smaller 131I treatment dose tended to the lower in vivo131I residual activity. Conclusions:Age, BMI, BMR and TSH levels are the influencing factors for the change in total activity in patient body after 131I treatment of DTC. Radiation dose assessment based on the above indicators can provide a reference for adjusting the length of hospitalization time.

Progress in Re-differentiating Therapy of Radioiodine-refractory Differentiated Thyroid Cancer / 肿瘤防治研究

The majority patients of differentiated thyroid carcinoma (DTC) with indolent progression have general good prognosis after standard primary treatments including surgery, thyroid stimulating hormone (TSH) suppression and radioactive iodine (RAI) therapy. However, there are still some patients suffered from recurrence or distant metastasis after initial treatment. They may lose the ability of uptaking iodine during their natural course of disease or treatment and could not benefit from subsequent RAI treatment, which will result in radioiodine-refractory differentiated thyroid cancer (RAIR-DTC). Options are very limited for RAIR-DTC patients, which is associated with a poor prognosis. Recently, with the research advances on the molecular mechanism of RAIR-DTC, redifferentiation combined with RAI therapy have been increasingly used to treat RAIR-DTC, and some outcomes are quite encouraging. This paper reviews the progress of signaling pathway inhibitors, histone deacetylase inhibitors, DNA methyltransferase inhibitors, retinoids and peroxisome proliferator-activated receptor agonists in redifferentiating therapy of RAIR-DTC.

Studies on newly recognized chronic sialadenitis / 北京大学学报(医学版)

Some kinds of chronic sialadenitis were recognized during the recent years. They have specific pathogenesis, clinical and histopathologic appearances, and require specific treatment. IgG4-related sialadenitis (IgG4-RS) is one of the immune-mediated diseases, characterized by tumefactive lesions. The incidence of IgG4-RS obviously increased during the past 30 years. The study on the potential relationship between occupational exposure to chemical substances and the incidence of IgG4-RS showed that subjects with occupational exposure to agents known to cause IgG4-RD had an increased risk for IgG4-RS. Surgical excision of involved SMG could not control the disease progression, which is not recommended for treatment of IgG4-RS. The combination of glucocorticoid and steroid-sparing agents is effective for treating IgG4-RS, and restores salivary gland function. Radioiodine induced sialadenitis (RAIS) is one of the common complications of postoperative adjuvant treatment of differentiated thyroid cancer by 131I. The incidence of the disease is related to radiation dosage. Clinically, the patients suffered from swelling and tenderness in the buccal or submandibular regions, especially during the mealtime. Imaging appearances are similar to those of chronic obstructive sialadenitis. Conservative managements, such as gland massage, sialagogues, are the mainstream methods in the treatment of RAIS. Sialendoscopy is feasible for RAIS, but not as effective as conventional obstructive sialadenitis (COS). Therefore the prevention of RAIS is crucial. Eosinophilic sialodochitis (ES) is a new type of chronic inflammatory disease of the salivary gland related to allergy. It has characteristics of swelling of multiple major salivary glands, strip-like gelatinous plugs discharged from the duct orifice of the gland, elevated level of serum IgE and eosinophils in peripheral blood, infiltration of eosinophils and IgE positive plasma cells in the tissues, allergic history, increased expression of allergy-related cytokines, such as IL-4, IL-5, IL-13, and eotaxin, which suggest allergic reactions as a potential pathogenesis of the disease. The clinical, laboratory, histological, and immunohistochemical characteristics of ES are significantly different from conventional obstructive sialadenitis (COS). Therefore, it is suitable to separate ES from COS. Conservative managements, such as self-maintenance therapy and anti- allergic modality are the choices of treatment for ES. Based on the results of our comprehensive studies a new classification of chronic sialadenitis is suggested.

Prognostic factors in patients with advanced differentiated thyroid cancer treated with multikinase inhibitors - a single Brazilian center experience

ABSTRACT Objective: The aim of this study was to describe the real-world experience multikinase inhibitors (MKI) in the treatment advanced differentiated thyroid carcinoma (DTC) refractory to radioactive iodine (RAIR) therapy. Subjects and methods: We reviewed the records of all patients with MKI-treated DTC from 2010 to 2018. Progression free survival (PFS), response rates (RR) and adverse events (AE) profiles were assessed. Clinical parameters were compared between groups with different outcomes (disease progression and death) to identify possible prognostic factors and benefit from treatment. Results: Forty-four patients received MKI for progressive RAIR DTC. Median PFS was 24 months (10.2-37.7) and median overall survival (OS) was 31 months. Best overall response was complete response in one patient (4.5%), partial response in nine (20.4%), stable disease in twenty-two (50%), and progressive disease (PD) in twelve (27.3%). Seventy-two point 7 percent patients had clinical benefit and AE were mild in most cases (82.7%). Progressive patients were more likely to have FDG positive target lesion than those who did not progress (p = 0.033) and higher maximum SUV on target lesions (p = 0.042). Presence of lung-only metastasis and lower thyroglobulin (Tg) during treatment was associated with stable disease (p = 0.015 and 0,049, respectively). Patients with shorter survival had larger primary tumor size (p = 0.015) and higher maximum SUV on target lesions (p = 0.023). Conclusion: Our findings demonstrate safety and effectiveness of MKI in patients with advanced RAIR DTC. We were able to identify as possible prognostic markers of better outcomes: absence of FDG uptake on target lesions, lower maximum SUV on PET-CT, presence of lung-only metastasis and lower Tg during treatment.

Captación tiroidea de yodo radioactivo 131 en 24 horas en adultos jóvenes eutiroideos residentes de gran altitud / Thyroid uptake of radioactive iodine 131 in 24 hours in eutiroid young adults residents at high altitude

INTRODUCCIÓN: el tiroides exhibe una gran avidez por el yodo radioactivo (I131) que al ser fijado por ésta glándula puede determinarse, desde afuera, aprovechando el hecho de que las radiaciones gamma atraviesan los tejidos blandos del cuello y pueden registrarse (Gammagrafía) a distancias apreciables. Desde 1962 Bolivia cuenta con esta tecnología, sin embargo, no cuenta con trabajos similares desde la declaración de país libre de enfermedades secundarias a la deficiencia de Yodo en 1997. El objetivo fue determinar valores de la captación tiroidea de I131 a las 24 horas en adultos jóvenes eutiroideos, residentes de gran altitud. MÉTODO: se realizó un estudio descriptivo transversal, en 76 sujetos obtenidos por intención y seleccionados mediante una entrevista clínica, examen físico dirigido y un consentimiento informado. El procedimiento fue ejecutado por personal calificado en el INAMEN siguiendo las recomendaciones de la OIEA. RESULTADOS: el valor de la captación tiroidea de I131 en 24 horas fue de 18,23 + 5,79% (rango 7,70 ­ 39,70). DISCUSIÓN: los expertos recomiendan establecer valores de referencia actualizados en cada región. Se han descrito variaciones de los valores normales influenciados por el sexo y edad; esta última, aparentemente por una hipofunción tiroidea inversamente proporcional con la edad. CONCLUSIÓN: el valor referencial encontrado en nuestro estudio es concordante con los establecidos en el extranjero, sin embargo, con una tendencia incrementada. Podría deberse a la secuencia cronológica de los estudios comparados en países que ya habían establecido políticas de yodación más tempranamente.

INTRODUCTION: the thyroid exhibits a great avidity for radioactive iodine (I131) which, when fixed by this gland, can be determined from the outside, taking advantage of the fact that gamma radiation passes through the soft tissues of the neck and can be registered (scintigraphy) at appreciable distances. Since 1962, Bolivia has had this technology, however, it does not have similar studies since the declaration of a country free of diseases secondary to iodine deficiency in 1997. The objective was to determine values of the thyroid uptake of I131 at 24 hours in euthyroid young adults, high altitude residents. METHOD: a descriptive cross-sectional study was carried out in 76 subjects obtained by intention and selected by means of a clinical interview, directed physical examination and informed consent. The procedure was carried out by qualified personnel at INAMEN, following IAEA recommendations. RESULTS: the value of the thyroid uptake of I131 in 24 hours was 18.23 + 5.79% (range 7.70 - 39.70). DISCUSSION: experts recommend establishing up-to-date reference values in each region. Variations in normal values influenced by sex and age have been described; the latter, apparently due to a thyroid hypofunction inversely proportional to age. CONCLUSION: the reference value found in our study is consistent with those established abroad, however, with an increased trend. It could be due to the chronological sequence of comparative studies in countries that had already established iodination policies earlier.

Metástasis raras de cáncer papilar de tiroides en músculo esquelético: serie de casos / Rare metastases of papillary thyroid cancer in skeletal muscle: case series

Las metástasis del carcinoma papilar de tiroides (CPT) generalmente son a nivel locorregional, la diseminación a distancia es poco habitual, sin embargo la invasión de tejidos blandos aunque inusual puede ocurrir, y afecta negativamente la supervivencia. El presente estudio describe una serie de casos de Metástasis Musculares de CPT. Se realizó un estudio transversal de un solo centro que evaluó diez pacientes con CPT con metástasis en músculo. La edad de los pacientes fue entre 46 a 77 años, siendo la edad promedio de 60 años, 7 de los cuales fueron de sexo masculino que corresponde al 70%, todos con antecedente de CPT con respuesta estructural incompleta, además de las metástasis en músculo presentaron afectación de tres o más órganos, con necesidad de varios tratamientos, cada paciente registró entre 1 a 8 cirugías, recibieron entre 100 a 780mCi de I131 (yodo radiactivo), ocho ameritaron radioterapia, todos tuvieron indicación de tratamiento con ITK, sin embargo solo cuatro pacientes tuvieron acceso a dicho medicamento. La mayoría de las metástasis del CPT en músculo fueron diagnosticadas en los estudios de imagen PET/ CT, después de la tiroidectomía el tiempo de su presentación fue muy variable entre 1 a 18 años, el número de músculos comprometidos se reporta entre uno a cuatro, siendo el glúteo (4 casos) el músculo metastásico más frecuente. La presencia de metástasis musculares empeora el pronóstico en nuestra serie de pacientes.

Metastases of thyroid papillary carcinoma (CPT) are generally at the locoregional level, the dissemination from a distance is unusual, however the invasion of soft tissues, although rare can occur, and it negatively affects survival. The present study describes several Muscular Metastases of CPT cases. A transversal study in one only center was performed and assessed ten patients CPT metastases in muscles.The patients age ranged from 46 to 77, being the average age of 60, and 7 of them were male, corresponding to the 70%, everyone with CPT records with an incomplete structural response. Besides muscular metastases they also presented issues with three or more organs, needing many treatments. Each patient registered between 1 to 8 surgeries, they received between 100 to 780mCi of I131. Eight required radiotherapies, everyone required treatment with ITK, however, just four patients had access to that medication. Most of the CPT metastases in muscles were diagnosed in PET/CT image studies, after the thyroidectomy, the time for its presentation was very variable between 1 to 18 years, the number of compromised muscles is reported between one to four, being the buttock (4 cases) the most frequently muscle with metastases. The presence of muscular metastases aggravates the prognosis in our series of patients.

Influence of 131I therapy on parathyroid hormone in patients with differentiated thyroid cancer / 中华内分泌代谢杂志

Objective:This study aimed to investigate the influence of 131I therapy on parathyroid hormone (PTH) in differentiated thyroid cancer (DTC) patients. Methods:Clinical data were collected from 353 DTC patients (121 males and 232 females) with normal initial PTH (baseline PTH) and normal serum calcium who received 131I therapy, and tetany, limbs anesthesia, or paresthesia after the 131I therapy were also collected. Comparisons were performed on the changes of PTH, serum calcium, and serum phosphorus before and after 131I therapy. According to gender, age, histology, American Joint Committee on Cancer (AJCC) stages, administered activity, and residual thyroid tissue, further analyses were done for the difference of changes of PTH. Paired t-tests and Pearson χ 2 test were used to conduct statistics. Results:No patients suffered from tetany, limbs anesthesia, or paresthesia, etc. PTH showed a significant decrease [(39.83±16.94)μg/L vs (36.98±16.31)μg/L, P<0.01] after the 131I therapy. Serum calcium also decreased mildly [(2.30±0.12)mmol/L vs (2.27±0.14)mmol/L, P<0.01]. There was no significant difference in changes of PTH in gender, age, histology, AJCC stages, administered activity, and residual thyroid tissue. Conclusions:PTH of DTC patients decreased mildly after 131I therapy, and no hypocalcemia occurred. The change of PTH was not associated with sex, age, histology, AJCC stages, administered activity, and residual thyroid tissue.

Severe radiation thyroiditis after radioactive iodine for treatment of Graves' disease

Radiation thyroiditis resulting from radioactive iodine-131 treatment for Graves' disease is an uncommon complication. Although a majority of patients are asymptomatic or manifest mild symptoms that can be managed conservatively, published literature describing severe radiation thyroiditis resulting in significant morbidity is lacking. We herein report on six patients with severe radiation thyroiditis that resulted in hospitalisation, including an unusual complication of myopericarditis.

De Novo Extra-Thyroidal Manifestations of Graves’ Disease presenting 16 years after Total Thyroidectomy for Thyroid Cancer / Journal of the ASEAN Federation of Endocrine Societies

@#We present a 61-year-old Chinese female who had a history of angioinvasive follicular thyroid cancer (FTC) treated with total thyroidectomy 16 years ago, without radioactive iodine (RAI) treatment who now presents with de novo pretibial myxedema (PTM) followed by active severe Graves’ ophthalmopathy (GO) requiring pulse steroids and radiotherapy.

Intermediate-risk thyroid carcinoma: indicators of a poor prognosis

ABSTRACT Objective: The intermediate-risk (IR) category includes tumors with different degrees of aggression. We aimed to identify the risk factors associated with unfavorable response to initial treatment and compare the effect of low/high radioactive iodine (RAI) therapy. Subjects and methods: A total of 614 IR patients were selected from a database, during 1972-2015. All patients underwent total thyroidectomy and RAI therapy and were reclassified after 12-18 months into the favorable (complete/indeterminate) response group and the unfavorable (biochemical/incomplete structural) response group. A total of 92 patients were assessed for late response (mean: 9.19 ± 5.73 years). Age, gender, tumor size, histology, multifocality, vascular invasion, extrathyroidal extension, presence and number of lymph node metastasis, and stimulated thyroglobulin at ablation (sTg) were evaluated. Results: Mean age at diagnosis was 41.47 ± 15.81 years, and 83.6% of the patients were female. Within 12-18 months after initial therapy, unfavorable response was detected in 41.2% of the patients and was associated, in multivariate analysis, with lymph node metastasis (p = 0.041; odds ratio [OR] = 1.9), presence of more than five metastatic lymph nodes (p = 0,017; OR = 2.6), and sTg > 10 ng/mL (p = 0.005; OR = 10.0). For patients with a longer follow-up, sTg >10 ng/mL was associated with unfavorable response (p = 0.002; OR = 6.8). A higher RAI dose was not related to better prognosis at the end of the follow-up. Conclusion: A sTg level of >10 ng/mL and lymph node metastasis were associated with an unfavorable response 12-18 months after initial treatment. A RAI dose below 150 mCi was proven sufficient to treat IR patients.

Quality of Life in Patients with Papillary Thyroid Microcarcinoma According to Treatment: Total Thyroidectomy with or without Radioactive Iodine Ablation

BACKGROUND: Recently, there has been some controversy regarding the role of radioactive iodine (RAI) ablation in the treatment of low-risk differentiated thyroid carcinoma (DTC), especially papillary thyroid microcarcinoma (PTMC). This study aimed to compare quality of life (QoL) parameters between patients with PTMC who underwent total thyroidectomy (TT) alone and those who underwent TT with RAI ablation.METHODS: In this cross-sectional study, patients with PTMC who underwent TT with/without RAI remnant ablation were prospectively enrolled between June 2016 and October 2017. All patients completed three questionnaires: the 12-item short-form health survey (SF-12), thyroid cancer-specific quality of life (THYCA-QoL) questionnaire, and fear of progression (FoP) questionnaire.RESULTS: The TT and TT with RAI groups comprised 107 and 182 patients, respectively. The TT with RAI group had significantly lower serum thyrotropin (TSH) levels than the TT group. However, after matching for TSH levels between the groups (n=100 in both groups), there were no significant differences in baseline characteristics. According to the SF-12, the score for general health was significantly lower in the TT with RAI group than in the TT group (P=0.047). The THYCA-QoL also showed a significant difference in the “felt chilly” score between groups (P=0.023). No significant differences in FoP scores were observed between the groups.CONCLUSION: Patients with PTMC who underwent TT with RAI ablation experienced more health-related problems than those managed with TT alone. These findings support the idea that RAI ablation should be carefully considered in patients with low-risk DTCs.

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.

68Ga-PSMA: a One-stop Shop in Radioactive Iodine Refractory Thyroid Cancer? / 대한핵의학회잡지

We report a case of a 47-year-old female known with metastatic papillary thyroid cancer. Her treatment history included total thyroidectomy and 3 previous radio ablations with a cumulative dose of 950 mCi of ¹³¹I. On follow-up, her thyroglobulin levels had demonstrated a rising trend (from 3789.0 to 4240.0 ug/L) despite a ¹²³I whole-body scan demonstrating a reduction in tracer avid lesions. She was suspected of having radio-resistant disease. The patient underwent both ¹⁸F-FDG and ⁶⁸Ga-PSMA PET/CT imaging with both scans demonstrating congruent lesions however with far greater intensity on the ⁶⁸Ga-PSMA study.

Theranostics in Bangladesh: Current Status, Challenges, and Future Perspective / 대한핵의학회잡지

BACKGROUND AND CURRENT STATUS OF THERANOSTICS: Therapeutic nuclear medicine (NM) in Bangladesh began in the early 1980s with the application of radioactive iodine for treatment of thyroid cancer and primary hyperthyroidism. Since then, NM practice has remarkably developed in the country with the advancement of instrumentation, radiopharmacy, and information technology. The government took the initiative to establish four PET-CTcenters at different NMcenters, including one at the National Institute of Nuclear Medicine and Allied Sciences (NINMAS). A further development is the installation of a cyclotron center (18-MeV cyclotron) at NINMAS by the government's fund. Currently, NM is providing good health services to oncology patients throughout the country. More than 20 NM centers are functioning in different parts of the country, and therapeutic NM has an important place. However, conventional radioactive iodine still remains the major theranostic application.CHALLENGES AND FUTURE PERSPECTIVE: The expansion and development of therapeutic NM for other cancers have been limited due to a number of challenging factors. A brief overview of the history and current status ofNMin Bangladesh is presented here with an examination of factors that pose as obstacles to the introduction and development of new therapeutic technologies. Finally, future perspectives are discussed with ways to mitigate existing problems and challenges.

Differentiated Thyroid Cancer and Radioactive Iodine: Past, Present and Future

Radioiodine has been known as an important and safe armamentarium in the diagnosis and treatment of differentiated thyroid cancer (DTC) for more than 70 years. The 2015 guidelines from the American Thyroid Association (ATA) for adults with thyroid nodules and DTC seem to be the most comprehensive guidelines in the thyroid cancer field. The 2015 ATA guidelines provided an advance in evidence-based management of DTC, and resulted in a significant change in the patterns of practice regarding the application of the radioiodine. However, the 2015 ATA guidelines also provoked much controversy because a substantial portion of the recommendations announced were not based on sufficiently strong evidence. While the number of radioiodine administrations in Korea in the year of 2018 has decreased to a level less than 50% of that in 2013, in this review, we address some of the current issues and controversies regarding the application of radioiodine for the diagnosis, ablation and treatment of DTC, especially related to the 2015 ATA guidelines. Possible strategies for the achievement of better quality in radioiodine imaging and improvement in treatment efficiency that can be used in the near future are also discussed here.