Prospective study to evaluate radioactive iodine of 20 mCi vs 10-15 mCi in Graves' disease

OBJECTIVES

To assess whether increasing radioactive iodine dose can increase treatment efficacy in Graves' disease.

METHODS

A prospective study was conducted, including 106 patients receiving 20 mCi (740 MBq) radioactive iodine (RAI), compared with a retrospective data, including 113 patients receiving 10-15 mCi (370-555 MBq) RAI. Remission and failure rates were evaluated at 6 months post-RAI. Statistical analysis was performed using logistic regression and Kaplan-Meier curves.

RESULTS

Patients receiving 20 mCi RAI demonstrated a significantly higher remission rate compared to the 10-15 mCi group (82.1% vs 66.4%, p = 0.009). Median time to remission was shorter in the 20 mCI group (3 vs 4 months, p = 0.002). Hypothyroidism at 6 months was more prevalent in the 20 mCi group (67% vs 53%, p = 0.03). Larger thyroid size (> 60 g) was associated with treatment failure (p = 0.02).

CONCLUSIONS

Higher dosage (20 mCi) RAI showed superior efficacy in achieving remission compared to lower dosages (10-15 mCi) in Graves' disease treatment.

Efficient capture of iodine in steam and water media by hydrogen bond-driven charge transfer complexes

Untreated radioactive iodine (129I and 131I) released from nuclear power plants poses a significant threat to humans and the environment, so the development of materials to capture iodine from water media and steam is critical. Here, we report a charge transfer complex (TCNQ-MA CTC) with abundant nitrogen atoms and π-conjugated system for adsorption of I2 vapor and I3- from aqueous solutions. Due to the synergistic binding mechanism of benzene/triazine rings and N-containing groups with iodine, special I-π and charge transfer interaction can be formed between the guest and the host, and thus efficient removal of I2 and I3- can be realized by TCNQ-MA CTC with the adsorption capacity up to 2.42 g/g and 800 mg/g, respectively. TCNQ-MA CTC can capture 92% of I3- within 2.5 min, showing extremely fast kinetics, excellent selectivity and high affinity (Kd = 5.68 × 106 mL/g). Finally, the TCNQ-MA CTC was successfully applied in the removal of iodine from seawater with the efficiency of 93.71%. This work provides new insights in the construction of charge transfer complexes and lays the foundation for its environmental applications.

Presentation and treatment of two cases of malignant struma ovarii

BACKGROUND

Malignant Struma Ovarii (MSO) is a rare type of germ cell tumour which is diagnosed postoperatively on surgical pathology specimens by the presence of differentiated thyroid cancer in mature cystic teratomas in the ovaries. Treatment and follow-up procedures are not clearly established due to the paucity of MSO cases. CASE 1: A 44-year-old multiparous female presented with an irregular period. Ultrasound showed a left ovarian lesion mostly a dermoid cyst, however, CT showed a 3.8 × 2.7 × 4 cm complex cystic lesion with thick septation and enhancing soft tissue component. Laparoscopic left salpingo-oophorectomy was performed and histopathology showed a follicular variant of papillary thyroid carcinoma arising in a mature cystic teratoma. Peritoneal cytology was positive for malignancy. A thyroid function test was normal before surgery. Total thyroidectomy was performed followed by radioactive (RAI) iodine therapy. Later, a total laparoscopic hysterectomy and right salpingo-oophorectomy were performed. There is no evidence of recurrent disease during the 26-months follow-up. CASE 2: A 46-year-old single female presented with left lower abdominal pain that had persisted for 2 months. Imaging revealed an 8 × 9 × 9.5 cm left ovarian mass. Laparoscopic left salpingo-oophorectomy was performed and histopathology showed mature cystic teratoma with small papillary thyroid cancer. CT showed no evidence of metastatic disease. Later, the patient had a total thyroidectomy followed by radioactive (RAI) iodine therapy. She was started on thyroxine and later had total abdominal hysterectomy and right salpingo-oophorectomy.

CONCLUSION

MSO is a very rare tumour. Preoperative diagnosis is very difficult because of the nonspecific symptoms and the lack of specific features in imaging studies. Also, there is no consensus on the optimal treatment of women with MSO. Our two cases add to the limited number of MSO cases.

Clinical outcomes and implication of radioactive iodine therapy on cancer-specific survival in WHO classification of FTC

BACKGROUND

The clinical outcomes and implications of radioactive iodine therapy (RAIT) on cancer-specific survival (CSS) in World Health Organization (WHO) classification of follicular thyroid carcinoma (FTC) are not well established.

MATERIAL AND METHODS

The data of eligible patients with minimally invasive FTC (mi-FTC), encapsulated angioinvasive FTC (ea-FTC), or widely invasive FTC (wi-FTC) between 2000 and 2020 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Cancer-specific survival (CSS), the primary outcome, was compared among the three subtypes of FTC patients before and after adjusting for differences using propensity score matching (PSM). The FTC patients in different subtypes were then divided into two groups: the RAIT group and the no-RAIT group. Cox proportional hazards regression analyses were applied to discover the relationships of factors associated with CSS in the each PSM cohort.

RESULTS

A total of 2433 mi-FTC patients, 216 ea-FTC patients, and 554 wi-FTC patients were enrolled in the original cohorts, respectively. Patients with mi-FTC or ea-FTC had similar CSS (p =0.805), which was better than that of patients with wi-FTC (p <.001; p =0.021). Cox proportional hazards regression analysis revealed that RAIT was not associated with improved CSS in either the mi-FTC PSM cohort (HR =1.21, 95% CI=0.46-3.18, p =0.705) or the wi-FTC PSM cohort (HR =0.56, 95% CI=0.35-1.08, p =0.086). However, subgroup analysis demonstrated that wi-FTC patients with N1 stage (HR =0.44, 95% CI=0.20-0.99, p =0.018) or M1 stage (HR =0.25, 95% CI=00.11-0.53, p <.001) could gain CSS advantage from RAIT.

CONCLUSIONS

The RAIT can provide a CSS advantage for wi-FTC patients who with N1-stage or M1-stage disease.

Efficient adsorption of radioactive iodine by covalent organic framework/chitosan aerogel

Radioactive iodine is considered one of the most dangerous radioactive elements in nuclear waste. Therefore, effective capture of radioactive iodine is essential for developing and using nuclear energy to solve the energy crisis. Some materials that have been developed for removing radioactive iodine still suffer from complex synthesis, low removal capacity, and non-reusability. Herein, covalent organic framework (COF)/chitosan (CS) aerogels were prepared using vacuum freeze-drying, and the COF nanoparticles were tightly attached on the green biomass material CS networks. Due to the synergistic effect of both COF and CS, the composite aerogel shows a three-dimensional porous and stable structure in the recycle usage. The COF/CS aerogel exhibits excellent iodine adsorption capacity of 2211.58 mg g-1 and 5.62 g g-1 for static iodine solution and iodine vapor, respectively, better than some common adsorbents. Furthermore, COF/CS aerogel demonstrated good recyclability performance with 87 % of the initial adsorption capacity after 5 cycles. In addition, the interaction between iodine and imine groups, amino groups, and benzene rings of aerogel are the possible adsorption mechanisms. COF/CS aerogel has excellent adsorption properties, good chemical stability, and reusable performance, which is a potential and efficient adsorbent for industrial radioactive iodine adsorption from nuclear waste.

Unraveling the mechanism of iodate adsorption by anthocyanin-rich fruit waste as green adsorbents for Applications of radioactive iodine remediation in water environment

In aquatic settings, radioactive iodine from nuclear waste can exist as iodate (IO3-). This study explored the efficiency and mechanism of IO3- adsorption by minimally modified anthocyanin-based adsorbents. Pomegranate peels and mangosteen pericarps were selected from an initial screening test and could remove over 70% of 10 mg/L IO3-. The adsorbents yielded adsorption capacity (q) of 9.59 mg/g and 2.31 mg/g, respectively, at room temperature. At 5 °C, q values increased to 14.5 and 5.13 mg/g, respectively. Pomegranate peels showed superior performance, with approximately 4 times the anthocyanin content of mangosteen pericarps. Both adsorbents took 120 min to reach adsorption equilibrium, and no desorption was observed after 8 days (I-131 half-time). Confirmation of physisorption was indicated by the fit of the pseudo-first-order reaction model, negative entropy (exothermic), and negative activation energy (Arrhenius equation). IO3- inclusion was confirmed through adsorbent surface modifications in scanning electron microscope images, the increased iodine content post-adsorption in energy-dispersive X-ray spectroscopy analysis, and alterations in peaks corresponding to anthocyanin-related functional groups in Fourier transform infrared spectroscopy analysis. X-ray absorption near-edge spectroscopy at 4564.54 eV showed that iodine was retained in the form of IO3-. Through the computational analysis, electrostatic forces, hydrogen bonds, and π-halogen interactions were deduced as mechanisms of IO3- adsorption by anthocyanin-based adsorbents. Anthocyanin-rich fruit wastes emerged as sustainable materials for eliminating IO3- from water.

The value of the first postoperative diagnostic I-131 scan in patients with papillary thyroid carcinoma

OBJECTIVE

To explore the feasibility of the postoperative diagnostic 131I whole-body planar scans (Dx-WBS) in papillary thyroid cancer (PTC) patients, and to clarify its value for accurate staging, risk stratification, and postoperative radioactive iodine (RAI) treatment management.

DESIGN

Retrospective study from 2015 to 2021.

SETTING

A total of 1294 PTC patients in the tertiary referral hospital.

PARTICIPANTS

Patients with differentiated thyroid cancer who underwent total/subtotal thyroidectomy were included. Patients with non-PTC pathological type, non-first RAI treatment, and incomplete data such as Dx-WBS and postablation WBS (Rx-WBS) were excluded.

METHODS

The diagnostic efficacy of Dx-WBS was calculated with Rx-WBS as the reference. All patients were initially staged by the 8th edition of TNM staging, and risk stratification was performed based on clinical and pathological information. After Dx-WBS, the risk stratification was re-evaluated, and management was reconfirmed.

RESULTS

The detection rates of Dx-WBS for residual thyroid, cervical lymph nodes, upper mediastinal lymph nodes, lung, and bone distant metastasis were 97.6%, 78.3%, 82.1%, 66.7%, and 61.2%, respectively. The risk stratification of 113 patients (8.7%) changed after Dx-WBS, of which 107 patients changed from low to intermediate risk, 2 from low to high risk, and 4 from medium to high risk. A total of 241 patients (18.6%) adjusted the RAI regimen after Dx-WBS.

CONCLUSION

This study confirms the diagnostic efficacy of the postoperative Dx-WBS in PTC patients and the value of Dx-WBS in accurately assessing risk stratification, as well as assisting in determining RAI treatment.

Malignant degeneration of thyroglossal duct cysts: Clinical aspects, imaging findings and management: Case series

INTRODUCTION AND IMPORTANCE

Thyroglossal duct cysts (TDCs) are congenital anomalies that can rarely undergo malignant transformation, with approximately 1 % of operated TDCs demonstrating malignant degeneration. Therapeutic management and follow-up methods are still controversial subjects.

CASE SERIES PRESENTATION

We report 3 cases of a papillary carcinoma of thyroid occurring in a thyroglossal duct cyst. The diagnosis was suspected preoperatively in 2 patients, hence the indication of frozen section examination. All patients underwent Sistrunk procedure associated with total thyroidectomy and central neck dissection. Concomitant papillary thyroid carcinoma was found in 2 patients. A complementary treatment by radioactive iodine 131 with frenetic hormone therapy was undertaken in all the cases. The follow-up showed no recurrence.

CLINICAL DISCUSSION

The clinical presentation of thyroglossal duct cyst carcinoma is often nonspecific, posing challenges in early diagnosis. The chosen treatment strategy, involving the Sistrunk procedure, total thyroidectomy, and central neck dissection, along with adjuvant therapy using radioactive iodine 131 and frenetic hormone therapy, was effective in preventing recurrence.

CONCLUSION

The management of degenerated TDC is based on a multidisciplinary approach. Papillary carcinomas of TDC generally have a good prognosis.

Association of radioactive iodine treatment in differentiated thyroid cancer and cardiovascular death: a large population-based study

PURPOSE

The risk of cardiovascular diseases' death (CVD) in patients with differentiated thyroid cancer (DTC) treated with radioactive iodine (RAI) after surgery has not been adequately studied.

METHODS

Data of DTC patients who received RAI after surgery were retrieved from the Surveillance, Epidemiology, and End Result (SEER) database (2004-2015). Standardized mortality rate (SMR) analysis was used to evaluate the CVD risk in patients with RAI vs general population. A 1:1 propensity score matching (PSM) was applied to balance inter-group bias, and Pearson's correlation coefficient was used to detect collinearity between variables. The Cox proportional hazard model and multivariate competing risk model were utilized to evaluate the impact of RAI on CVD. At last, we curved forest plots to compare differences in factors significantly associated with CVD or cancer-related deaths.

RESULTS

DTC patients with RAI treatment showed lower SMR for CVD than general population (RAI: SMR = 0.66, 95% CI 0.62-0.71, P < 0.05). After PSM, Cox proportional hazard regression demonstrated a decreased risk of CVD among patients with RAI compared to patients without (HR = 0.76, 95% CI 0.6-0.97, P = 0.029). However, in competing risk regression analysis, there was no significant difference (adjusted HR = 0.82, 95% CI 0.66-1.01, P = 0.11). The independent risk factors associated with CVD were different from those associated with cancer-related deaths.

CONCLUSION

The CVD risk between DTC patients treated with RAI and those who did not was no statistical difference. Noteworthy, they had decreased CVD risk compared with the general population.

Radiopharmaceuticals: A New Vista for Diagnosis and Treatment of Thyroid Cancer

Radiopharmaceuticals are in the diagnosis and treatment of cancerous and noncancerous diseases, and a hope for optimistic effort in the field of nuclear medicine. They play a crucial role in clinical nuclear medicine by providing a tool to comprehend human disease and create efficient treatments. A detailed analysis is provided regarding the crux of molecular imaging including PET and SPECT overview for the detection of cancers. For a specified understanding of radiation therapy, topics include ranging from the selection of radionuclide to its development and manufacture, and dosage requirements to establishing the importance of I- 131 Radiotherapy in thyroid cancer. In this review, we also discussed the current state of the art of nuclear medicine in thyroid cancer, including the role of radioiodine (RAI) therapeutic scans in the diagnosis of differentiated thyroid cancer. In addition, we established a brief outlook into the current status of the research in thyroid cancer and discussed the future directions in this field.

Lymph node ratio independently associated with postoperative thyroglobulin levels in papillary thyroid cancer

OBJECTIVES

To investigate the impact of the lymph node ratio (LNR) on postoperative thyroglobulin (Tg) levels in patients with papillary thyroid carcinoma (PTC).

PATIENTS AND METHODS

This was a retrospective, cohort study. The association between clinicopathological variables and postoperative unstimulated Tg (uTg) levels, preablative-stimulated Tg (sTg) levels, and postablative unstimulated Tg levels was analysed.

RESULTS

A total of 300 patients with PTC were identified. Multivariate logistic analysis showed that M classification (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.62-3.34), and postoperative thyroid-stimulating hormone levels (OR, 1.01; 95% CI, 1.01-1.02) were independently associated with postoperative uTg levels. One hundred and sixteen patients underwent radioactive iodine (RAI) therapy. Multivariate analysis showed that LNR in the central neck (OR, 1.24; 95% CI, 1.02-1.51), LNR in the lateral neck (OR, 1.73; 95% CI, 1.09-2.77), RAI dose (OR, 1.43; 95% CI, 1.21-1.69), and M classification (OR, 1.79; 95% CI, 1.22-2.61) were independently associated with preablative sTg levels. Tumour size (OR, 1.01; 95% CI, 1.00-1.01), LNR in the central neck (OR, 1.28; 95% CI, 1.08-1.51), LNR in the lateral neck (OR, 1.66; 95% CI, 1.10-2.49), RAI dose (OR, 1.54; 95% CI, 1.34-1.79), and M classification (OR, 1.56; 95% CI, 1.12-2.19) were also independently associated with postablative uTg levels.

CONCLUSION

LNR was independently associated with postoperative Tg levels in patients with PTC. Patients with high LNR were more likely to have incomplete biochemical responses after surgery.

Clinicopathological profile and management of thyroid carcinoma: a Sub-Saharan country experience

BACKGROUND

In Sudan, there is limited knowledge on the epidemiology, clinical characteristics and pathological patterns of thyroid cancer. To address this shortcoming, we studied the clinical, pathological and treatment patterns of thyroid cancer at the National Cancer Institute ‒ University of Gezira (NCI-UG), Sudan.

METHODS

We performed a retrospective health facility-based study of patients with thyroid cancer who were treated at NCI-UG from January 2009 to December 2017.

RESULTS

A total of 139 patients with thyroid cancer were identified during the study period. Tumors were more common among women (69%). Goiter was the main presenting symptom (85%). The most common type of thyroid cancer was follicular carcinoma (41%), followed by papillary carcinoma (24%), then anaplastic carcinoma (20%). The mean age of the women was 56.3 years (SD ± 14.7), compared to 52.5 years (SD ± 16.6) for the men. The frequencies of stage I, II, III, and IV were 17%, 22%, 16%, and 45%, respectively. Different types of thyroidectomies were performed in 79% of the cases, lobectomy in 4%, and no surgery in 17%. Only 28% of the cases received radioactive iodine. Palliative chemotherapy and radiotherapy were prescribed to 17% and 37% of the cases, respectively.

CONCLUSION

Thyroid cancer is more prevalent among women and most patients present at later stages. The dominance of follicular type suggests that the majority of this population is iodine-deficient.

The effect of selenium supplementation on sonographic findings of salivary glands in papillary thyroid cancer (PTC) patients treated with radioactive iodine: study protocol for a double-blind, randomized, placebo-controlled clinical trial

BACKGROUND

Thyroid cancer is a very damaging disease. The most common treatment for this disease includes thyroidectomy and then using radioactive iodine (RAI). RAI has many side effects, including a decrease in salivary secretions, followed by dry mouth and oral and dental injuries, as well as increased inflammation and oxidative stress. Selenium can be effective in these patients by improving inflammation and oxidative stress and by modulating salivary secretions. So far, only one clinical trial has investigated the effect of selenium on thyroid cancer patients treated with radioiodine therapy (RIT) conducted on 16 patients; considering the importance of this issue, to show the potential efficacy of selenium in these patients, more high-quality trials with a larger sample size are warranted.

METHODS

This is a parallel double-blind randomized controlled clinical trial that includes 60 patients aged 20 to 65 years with papillary thyroid cancer (PTC) treated with RAI and will be conducted in Seyyed al-Shohada Center, an academic center for referral of patients to receive iodine, Isfahan, Iran. Thirty patients will receive 200 µg of selenium for 10 days (3 days before to 6 days after RAI treatment) and another 30 patients will receive a placebo for the same period. Sonographic findings of major salivary glands, salivary secretions, and sense of taste will be evaluated before and 6 months after 10-day supplementation.

DISCUSSION

Due to its anti-inflammatory and antioxidant effects, as well as improving salivary secretions, selenium may improve the symptoms of thyroid cancer treated with radioactive iodine. In past studies, selenium consumption has not reduced the therapeutic effects of radiation therapy, and at a dose of 300 to 500 μg/day, it has not had any significant side effects in many types of cancer under radiation therapy.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials IRCT20201129049534N6 . Registered on 16 September 2021.

Follicular thyroid carcinoma with sternal metastasis: A case report

INTRODUCTION AND IMPORTANCE

Sternal metastasis of follicular thyroid cancer (FTC) is rare as only 15 cases have been reported in the literature in which most cases of sternal metastasis occurs form breast and lung cancer. Surgical excision of the metastatic mass provides the best option due to its curative benefit, symptomatic palliation, and better response to radioactive iodine.

CASE PRESENTATION

Herein, we present a 77-year-old female patient with a known history of follicular thyroid carcinoma with isolated sternal metastasis treated with total thyroidectomy and en-bloc resection of the metastasis, followed by chest wall reconstruction using pectoralis major muscle flap.

CLINICAL DISCUSSION

Surgical excision of metastatic FTC to sternum with chest wall reconstruction was seldom reported as the treatment of choice. In most cases in the literature, mesh was used. However, in our patient mesh was not used taking into consideration the drastic consequences of wound infection and the possible need for mesh retrieval in such a dangerous area in proximity to the mediastinum. We believe that myo-adipo-facial flap is a more reasonable and safe option.

CONCLUSION

In patients with FTC, large tumors and bone metastases are factors that indicate poor prognostic factors, both of which were present in our patient. However, surgical excision provides hope for a better quality of life as it enhances subsequent Radioactive Iodine (RAI) therapy.

Synthesis and characterization of Ag@Cu-based MOFs as efficient adsorbents for iodine anions removal from aqueous solutions

Due to the critical importance of capturing radioiodine from aquatic environments for human health and ecosystems, developing highly efficient adsorbent materials with rapid kinetics for capturing iodide ions in aqueous solutions is urgently needed. Although extensive research has been conducted on iodine adsorption in gas and organic phases, limited research has been dedicated to adsorption in aqueous solutions. An effective technique for removing iodide was proposed using Ag@Cu-based MOFs synthesized by incorporating Ag into calcined HKUST-1 with varying mass ratios of Ag/Cu-C. Extensive characterization using SEM, XRD, XPS, and nitrogen adsorption-desorption analysis confirmed successful incorporation of Ag in Cu-C. Batch adsorption experiments were conducted, demonstrating that the 5% Ag@Cu-C material exhibited a high adsorption capacity of 247.1 mg g^-1 at pH 3. Mechanism investigations revealed that Cu⁰ and dissolved oxygen in water generate Cu₂O and H₂O₂, while Ag and a small amount of CuO generate Ag₂O and Cu₂O. Furthermore, iodide ions in the solution are captured by Cu⁺ and Ag⁺ adsorption sites. These findings highlighted the potential of Ag@Cu-based MOFs as highly effective adsorbents for iodine anions removal in radioactive wastewater.

Morphological Characteristics of the Lacrimal Apparatus in its Obstruction of Various Genesis

Secondary acquired lacrimal duct obstruction (SALDO) is one of the complications of radioiodine therapy. The material was obtained during endoscopic dacryocystorhinostomy with revision of Hasner's valve in patients with PANDO (n = 7) in the distal segments of the nasolacrimal duct and in patients with SALDO (n = 7) after radioactive iodine therapy. The material was stained with hemotoxylin and eosin, alcyan blue, and by Masson method. Morphological and morphometric analyses were performed in semi-automatic mode. The results of histochemical staining of sections were translated into points taking into account the area and optical density (chromogenicity). The differences were considered significant at p < 0.05. It was shown that the nasolacrimal duct sclerosis is significantly lower (p = 0.029) in patients with SALDO than in patients with PANDO while fibrosis in the lacrimal sac is the same in patients of the compared groups.

Life-threatening Airway Complication After Radioactive Iodine Treatment: A Case Report and Review of the Literature

BACKGROUND/AIM

Radioactive iodine (RAI) treatment is a cornerstone of treatment of differentiated thyroid carcinoma. Although serious RAI-related complications are uncommon, there have been reports of airway emergencies. Here, a life-threatening airway complication after RAI treatment is reported and previously reported cases are reviewed.

CASE REPORT

A 79-year old man with Hürthle cell carcinoma and a remnant thyroid lobe after surgery developed an edema compromising the airway two days after receiving radioactive iodine treatment. An emergency awake intubation and tracheostomy were performed. He could be successfully de-cannulated 17 days later with no long-term complications.

CONCLUSION

Although rare, life-threatening airway complications after radioactive iodine treatment, especially with high dose treatment in patients with remaining thyroid tissue, can occur and these patients should be supervised where these complications can be managed.

Strategies for Treatment of Thyroid Cancer

More people are diagnosed with thyroid cancer than any other endocrine tumor. Differentiated thyroid cancer is often treated by removing the thyroid gland (thyroidectomy), iodizing radiation, or inhibiting thyroid stimulating hormone (TSH). Advanced thyroid carcinomas are notoriously resistant to chemotherapy, thus the pursuit of alternative treatments is vital. The best methods for treating individuals with advanced nonmedullary and medullary thyroid carcinomas are discussed in this post. Numerous tyrosine kinase inhibitors and antiangiogenic inhibitors, two types of novel target therapy, have shown promise in studies for individuals with thyroid cancer. Both the positive and unfavourable outcomes of clinical studies of these drugs were addressed. The findings presented here are encouraging, but more study is required to establish whether or not this method is effective in the treatment of thyroid cancer.

Quantitative Iodine-123 single-photon emission computed tomography/computed tomography for Iodine-131 therapy of an autonomously functioning thyroid nodule

PURPOSE

Autonomously functioning thyroid nodules (AFTNs) are treated with iodine-131 (I-131) therapy, which increases the risk of permanent hypothyroidism; however, the risk can be reduced by separately estimating the accumulated activity for the AFTN and extranodular thyroid tissue (ETT).

METHODS

A quantitative I-123 single-photon emission computed tomography (SPECT)/CT (5 mCi) was performed in one patient with unilateral AFTN and T3 thyrotoxicosis. The I-123 concentrations measured at 24 h were 12.26 µCi/mL and 0.11 µCi/mL in the AFTN and contralateral ETT, respectively. Thus, the I-131 concentrations and radioactive iodine uptake expected at 24 h by 5 mCi of I-131 were 38.59 µCi/mL and 0.31 for the AFTN and 0.34 µCi/mL and 0.007 for the contralateral ETT. The weight was calculated as CT-measured volume multiplied by 1.03.

RESULTS

In the AFTN patient with thyrotoxicosis, we administered 30 mCi of I-131, which would maximize the 24-h I-131 concentration in the AFTN (226.86 µCi/g) and maintain a tolerable concentration in the ETT (1.97 µCi/g). The percentage of I-131 uptake at 48 h post I-131 administration was 62.6%. The patient achieved a euthyroid state at 14 weeks and maintained the state until 2 years post I-131 administration with an AFTN volume reduction of 61.38%.

CONCLUSION

The pre-therapeutic planning of quantitative I-123 SPECT/CT may enable a therapeutic window for I-131 therapy, which directs optimal I-131 activity to effectively treat AFTN while preserving the normal thyroid tissue.

Short-term efficacy assessment of transarterial chemoembolization combined with radioactive iodine therapy in primary hepatocellular carcinoma

BACKGROUND

Transarterial chemoembolization (TACE) is an effective treatment for primary hepatocellular carcinoma (PHC). Radioactive iodine therapy has been used in the treatment of advanced PHC, especially in patients with portal vein tumor thrombosis. However, data on the therapeutic effect of TACE combined with radioactive iodine therapy in PHC are scarce.

AIM

To investigate the clinical efficacy of TACE combined with radioactive iodine implantation therapy in advanced PHC via perfusion computed tomography (CT).

METHODS

For this study, 98 advanced PHC patients were recruited and divided randomly into the study and control groups. Patients in the study group were treated with TACE combined radioactive iodine implantation therapy. Patients in the control group were treated with only TACE. The tumor lesion length, clinical effect, serum alpha-fetoprotein (AFP) and CT perfusion parameters were compared before and after therapy, and statistical analysis was performed.

RESULTS

There was no significant difference in tumor length and serum AFP between the study and control groups (P > 0.05) before treatment. However, the tumor length and serum AFP in the study group were lower than those in the control group 1 mo and 3 mo after therapy. After 3 mo of treatment, the complete and partial remission rate of the study group was 93.88%, which was significantly higher than the control group (77.55%) (P < 0.05). Before treatment, there were no significant differences between the two groups on the perfusion CT variables, including the lesion blood volume, permeability surface, blood flow, hepatic artery flow and mean transit time (P > 0.05). After 3 mo of treatment, all perfusion CT variables were lower in the study group compared to the control group (P < 0.05). The survival time of patients in the study group was 22 mo compared to 18 mo in the control group, which was significantly different [log rank (Mantel-Cox) = 4.318, P = 0.038].

CONCLUSION

TACE combined with radioactive iodine implantation in the treatment of advanced PHC can inhibit the formation of blood vessels in tumor tissue and reduce the perfusion level of tumor lesions, thereby improving the clinical efficacy and prolonging the survival time of patients.

Management of Chronic Sialadenitis due to Sjogren's Syndrome and Radioactive Iodine Therapy Using Sialendoscopy

INTRODUCTION

Sialendoscopy is a minimally invasive technique for the management of salivary gland disease. This work characterizes its utility for treating chronic sialadenitis due to Sjogren's syndrome and radioactive iodine (RAI) therapy.

METHODS

A single-center, retrospective review of patients undergoing sialendoscopy between March 2013 and May 2019 for the treatment of chronic sialadenitis due to Sjogren's or prior RAI therapy was performed.

RESULTS

Thirty-four patients with Sjogren's and 25 patients who received RAI were identified, undergoing a total of 86 procedures. Median age at presentation was 53 years with mean follow-up time of 14.3 months. Seventy-two procedures were performed on the parotid gland, four on the submandibular gland, and ten on both glands. Corticosteroid injection and duct dilation were performed most commonly. Sixteen patients required repeat procedure. All patients were symptomatically improved at follow-up visit.

DISCUSSION/CONCLUSION

These results support the idea that sialendoscopy offers symptomatic benefit for patients with chronic sialadenitis due to Sjogren's or RAI.

A systematic review

Adjuvant radioactive iodine (RAI) is administered to thyroid cancer patients following thyroidectomy for remnant tissue ablation and metastatic disease management. Patients are prepared with thyroid hormone withdrawal (THW) or recombinant human thyroid stimulating hormone (rhTSH). Long-term salivary gland dysfunction (LT-SGD) is a common, dosage-dependent, RAI adverse effect. Although rhTSH preparation seems to reduce LT-SGD, this effect could be due to lower RAI activity generally used in rhTSH-prepared patients. Therefore, this meta-analysis investigated the effect of preparation type on LT-SGD development. Literature search (PubMed, Medline, EmBase, Cochrane, Web of Science, LILACS, Google Scholar) was performed four times (January-November 2022) and studies reporting LT-SGD incidence ≥1 year after RAI in patients prepared with rhTSH/THW were identified. The LT-SGD risk ratio (RR) was estimated with various models considered for sensitivity analysis (fixed-effect, random-effects, study-quality adjusted, publication-bias adjusted, individual-patient-data meta-analysis adjusted for RAI). Subgroup analysis according to RAI activity (<3.7/≥3.7 GBq) also was performed. Literature search resulted in five studies (321 rhTSH, 632 THW patients). The pooled RRs according to various models were 0.65 (95% confidence interval -95CI, 0.49-0.86; fixed-effect); 0.62 (95CI, 0.38-1.02; random-effects); 0.72 (95CI, 0.54-0.96; quality adjusted); 0.76 (95CI, 0.58-0.99; publication-bias adjusted); 0.0.80 (95CI, 0.55-1.14; individual-patient-data meta-analysis). The pooled RRs stratified for RAI activity were 0.26 (95CI, 0.05-1.30) for <3.7 GBq; 0.75 (95CI, 0.57-0.98) for ≥3.7 GBq. The number of patients needed to be prepared with rhTSH to prevent one case of LT-SGD ranged between seven and thirty-seven. There is moderate-quality scientific evidence that rhTSH preparation may consistently protect salivary gland function.

Thyroid Receptor Antibody and the Development of Graves' Orbitopathy: Clinical Experience of using Radioiodine Ablation in the Management of Graves' Orbitopathy in post-iodine ablation hypothyroid patient

Graves' disease (GD) is the commonest cause of hyperthyroidism, accounted for 70-80% in iodine sufficient countries and up to 50% in iodine deficient countries. Combination of genetic predisposition and environmental factors influences the development of GD. Graves' orbitopathy (GO) represents the most common extra-thyroidal manifestation of GD with substantial impact on morbidity and quality of life. Expression of thyroid stimulating hormone receptor (TSHR) mRNA and protein in orbital tissues infiltrated by the activated lymphocytes produced by thyroid cells (Thyroid Receptor Antibody) results in the secretion of inflammatory cytokines that leads to the development of histological and clinical characteristics of GO. A subdivision of TRAb, thyroid stimulating antibody (TSAb), was found to have a close relationship with the activity and severity of GO, and suggested to be considered as a direct parameter of GO. Here, we present a 75-year-old female with a history of GD that has successfully been treated with radioiodine treatment, who developed GO 13 months after therapy while being hypothyroid with high TRAb level. The patient was given a second dose of radioiodine ablation to maintain GO with successful result.

Iodine uptake in brown seaweed exposed to radioactive liquid discharges from the reprocessing plant of ORANO La Hague

Iodine-129 is present in controlled liquid radioactive waste routinely released in seawater by the ORANO nuclear fuel reprocessing plant in La Hague (Normandy, France). Brown algae are known for their exceptional ability to concentrate iodine from seawater. They also potentially emit volatile iodine compounds in response to various stresses, such as during emersion at low tide. For these reasons, brown seaweed is routinely collected for radioactivity monitoring in the marine environment (Fucus serratus and Laminaria digitata). Despite the high concentration ratio, the exact mechanism of iodine uptake is still unclear. Chemical imaging by laser desorption/ionization mass spectrometry provided evidence that iodine is stored by kelps as I-. In this study we investigate in vivo iodine uptake in kelps (L. digitata) with an emphasis on seawater iodine chemical speciation. Our results showed that kelp plantlets were able to take up iodine in the forms of both IO3- and I-. We also observed transient net efflux of I- back to seawater but no IO3- efflux. Since the seaweed stores I- but takes up both IO3- and I-, IO3- was likely to be converted into I- at some point in the plantlet. One major outcome of our experiments was the direct observation of the kelp-based biogenic conversion of seawater IO3- into I-. On the basis of both IO3- and I- uptakes by the seaweed, we propose new steps in the possible iodine concentration mechanism used by brown algae.

Incidence and treatment outcomes of Graves' disease in Thailand: a single-center retrospective observational study

BACKGROUND

Treatment patterns and outcomes of Graves' disease (GD) are variable around the world. However, studies on treatment outcomes of GD from the Asian populations are limited. We aimed to evaluate treatment outcomes of GD in Thailand.

METHODS

Patients with new diagnoses of GD in a single center between 2014-2018 were retrospectively reviewed. The diagnosis of GD was based on clinical features, which included diffuse goiter, Graves' orbitopathy (GO), pretibial myxedema and acropachy.

RESULTS

The age-adjusted incidence of GD was 26.57 per 100,000 per year. The study included 355 patients aged 15 years or above with a follow-up period of at least 24 months. Antithyroid drug (ATD) was the most popular first-line treatment modality with 98.7% patients receiving the treatment, followed by radioactive iodine (RAI) treatment in 1.3% patients. The most effective treatment modality was surgery with a remission rate of 100%. ATD had a lowest remission rate of 23.8%. Multivariable Cox regression analysis showed GO (HR 1.76, 95% CI 1.08-2.88) and initial TSH < 0.01 uIU/ml (HR 1.61, 95% CI 1.14-2.28) were significant factors associated with an increased treatment failure rate.

CONCLUSION

Treatment failure with ATD in patients with GD was frequent in this population. The diagnosis of GD based solely on clinical features may explain the high treatment failure rate in this study. More definitive treatment could be used to prevent relapse and complications of the disease.

Synthesis and applications of bismuth-impregnated biochars originated from spent coffee grounds for efficient adsorption of radioactive iodine: A mechanism study

The adsorption of radioactive iodine, which is capable of presenting high mobility in aquatic ecosystems and generating undesirable health effects in humans (e.g., thyroid gland dysfunction), was comprehensively examined using pristine spent coffee ground biochar (SCGB) and bismuth-impregnated spent coffee ground biochar (Bi@SCGB) to provide valuable insights into the variations in the adsorption capacity and mechanisms after pretreatment with Bi(NO₃)₃. The greater adsorption of radioactive iodine toward Bi@SCGB (adsorption capacity (Q_e) = 253.71 μg/g) compared to that for SCGB (Q_e = 23.32 μg/g) and its reduced adsorption capability at higher pH values provide evidence that the adsorption of radioactive iodine with SCGB and Bi@SCGB is strongly influenced by the presence of bismuth materials and the electrostatic repulsion between their negatively charged surfaces and negatively charged radioactive iodine (IO₃^-). The calculated R² values for the adsorption kinetics and isotherms support that chemisorption plays a crucial role in the adsorption of radioactive iodine by SCGB and Bi@SCGB in aqueous phases. The adsorption of radioactive iodine onto SCGB was linearly correlated with the contact time (h^1/2), and the diffusion of intra-particle predominantly determined the adsorption rate of radioactive iodine onto Bi@SCGB (C_{stage II} (129.20) > C_{stage I} (42.33)). Thermodynamic studies revealed that the adsorption of radioactive iodine toward SCGB (ΔG° = -8.47 to -7.83 kJ/mol; ΔH° = -13.93 kJ/mol) occurred exothermically and that for Bi@SCGB (ΔG° = -15.90 to -13.89 kJ/mol; ΔH° = 5.88 kJ/mol) proceeded endothermically and spontaneously. The X-ray photoelectron spectroscopy (XPS) analysis of SCGB and Bi@SCGB before and after the adsorption of radioactive iodine suggest the conclusion that the change in the primary adsorption mechanism from electrostatic attraction to surface precipitation upon the impregnation of bismuth materials on the surfaces of spent coffee ground biochars is beneficial for the adsorption of radioactive iodine in aqueous phases.

Long term outcome after toxic nodular goitre

BACKGROUND

The purpose of treating toxic nodular goitre (TNG) is to reverse hyperthyroidism, prevent recurrent disease, relieve symptoms and preserve thyroid function. Treatment efficacies and long-term outcomes of antithyroid drugs (ATD), radioactive iodine (RAI) or surgery vary in the literature. Symptoms often persist for a long time following euthyroidism, and previous studies have demonstrated long-term cognitive and quality of life (QoL) impairments. We report the outcome of treatment, rate of cure (euthyroidism and hypothyroidism), and QoL in an unselected TNG cohort.

METHODS

TNG patients (n = 638) de novo diagnosed between 2003-2005 were invited to engage in a 6-10-year follow-up study. 237 patients responded to questionnaires about therapies, demographics, comorbidities, and quality of life (ThyPRO). Patients received ATD, RAI, or surgery according clinical guidelines.

RESULTS

The fraction of patients cured with one RAI treatment was 89%, and 93% in patients treated with surgery. The rate of levothyroxine supplementation for RAI and surgery, at the end of the study period, was 58% respectively 64%. Approximately 5% of the patients needed three or more RAI treatments to be cured. The patients had worse thyroid-related QoL scores, in a broad spectrum, than the general population.

CONCLUSION

One advantage of treating TNG with RAI over surgery might be lost due to the seemingly similar incidence of hypothyroidism. The need for up to five treatments is rarely described and indicates that the treatment of TNG can be more complex than expected. This circumstance and the long-term QoL impairments are reminders of the chronic nature of hyperthyroidism from TNG.

Treatment of post-radioactive iodine relapse of hyperthyroidism: comparison of long-term methimazole and radioactive iodine treatment

BACKGROUND

This study aimed to compare the time to achieve euthyroidism and sustained control of hyperthyroidism after treatment with radioactive iodine (RAI) or long-term methimazole (LT-MMI) in patients with post-RAI relapsed hyperthyroidism.

METHODS

Sixty four patients with recurrence of hyperthyroidism after RAI treatment were randomly assigned to either RAI or LT-MMI treatment. Both groups were followed every 1-3 months in the first year and then every 6 months for a total of 60 months.

RESULTS

In RAI and LT-MMI groups, mean age was 49.0 ± 12.1 and 50.1 ± 14.6 years and time of relapse of hyperthyroidism after previous RAI treatment was 23.2 ± 18.8 and 20.8 ± 17.1 months, respectively. At the end of study, in the LT-MMI group, 31 (97%) and 1 (3%) were euthyroid and hypothyroid, respectively; in the RAI group, 8 (25%) patients were euthyroid, whereas 18 (56%), 3 (9.5%) and 3 (9.5%) had overt hypothyroidism, subclinical hypothyroidism and hyperthyroidism, respectively. Mean time to euthyroidism was 9.4 ± 5.0 months in the RAI group and 3.5 ± 2.8 months in the LT-MMI group (p < 0.001). Patients in the RAI group spent 77.7 ± 14.0 percent and those in the LT-MMI group spent 95.2 ± 5.9 percent of 60 months in the euthyroid state (p < 0.001).

CONCLUSION

In patients with post-RAI relapse of hyperthyroidism, LT-MMI treatment was superior to radioiodine because of faster achievement of euthyroidism and more sustained control of hyperthyroidism during 60 months of follow-up.

Levothyroxine-induced serum free thyroxine response following radioactive iodine administration in patients thyroidectomized for differentiated thyroid cancer: A randomized controlled trial

PURPOSE

Patients undergoing thyroidectomy for differentiated thyroid cancer (DTC) may require 131-radioactive iodine (RAI) administration for remnant ablation or disease treatment. After ingestion, RAI resides within the gastrointestinal tract potentially leading to mucosal damage and abnormalities in the absorption of levothyroxine (LT4). The aim of this study was to evaluate whether serum FT4 peak, induced by a LT4 challenge, changes according to the LT4 formulation (solid or liquid) in both RAI and non-RAI-treated DTC patients.

METHODS

This was a monocentric controlled clinical trial, with a parallel two-groups (1:1) randomization of sequence of LT4 formulation. Patients received 200 mcg LT4 orally administered at 08:00 h, in both solid and liquid formulation, at one-week interval, at baseline and after 1, 3, and 6 months from RAI administration. At each time-point, circulating FT4 was evaluated both before LT4 assumption as well as after 1 and 3 h. FT4 increments were evaluated as area under the curve response (AUC). Analogous protocol with the same time-intervals was followed for non-RAI patients.

RESULTS

The trial included 29 consecutive DTC patients, nineteen of whom were submitted to RAI. In RAI subjects, we observed an overall significant reduction in serum FT4 increments with the most relevant decrease at the 1-month time-point, (FT4 AUC: 4.46 ± 0.72 (M ± SD) vs 4.07 ± 0.63 in baseline vs 1-month, P = 0.001) without any difference between the two LT4 formulations. No difference in serum FT4 AUC was found in non-RAI subjects.

CONCLUSION

LT4-induced serum FT4 responses are reduced following RAI administration in thyroidectomized DTC patients.

Efficient capture of radioactive iodine by ZIF-8 derived porous carbon

Due to the rapid diffusion of radioactive iodine, the demand for safe and efficient capture and storage of radioactive iodine is increasing worldwide. The use of porous carbon materials to capture iodine has aroused great interest. This work prepared porous carbon materials derived from polymetallic oxides of the zeolitic imidazolate framework (ZIF) by pyrolysis at 1000 °C. The carbon materials (CZIF-1000) have a high specific surface area of about 1110 m2/g and a total pore volume of 0.92 cm3/g. Adsorption studies have shown that the CZIF-1000 had significant adsorption performance for iodine, and the adsorption capacity can reach 790.8 mg/g at 8h. The potential mechanism of adsorption is that the carbonization causes the charge-transfer interaction and pore size distribution. Compared with the conventional adsorbents, the adsorbents showed faster kinetics and high extraction capacity for iodine. This experiment provides an effective method for designing a highly efficient adsorbent for iodine and broadens the ideas for developing new iodine extraction adsorbents.

Functional imaging in thyroid cancer patients with metastases and therapeutic implications

Functional imaging plays a central role in the management of thyroid cancer patients. In patients with a differentiated thyroid cancer (DTC), radioactive iodine (RAI) is used mostly with a therapeutic intent, either post-operatively or as the first line systemic treatment in patients with known structural disease. A whole body scan is performed a few days after the RAI administration, and this procedure is very sensitive to detect all tumor foci with RAI uptake. PET/CT with ¹⁸F-FDG complements the use of RAI at the initial evaluation of patients with high-risk DTC, during follow-up in those with rising serum thyroglobulin levels over time, for the work-up of patients with documented structural disease and for assessing the efficacy of focal or systemic treatment modalities. ¹⁸F-FDG uptake is a prognostic indicator in all these clinical conditions. A dosimetric approach with ¹²⁴I PET/CT showed encouraging results. Several functional imaging modalities are currently available for medullary thyroid carcinoma (MTC) patients. ¹⁸F-FDG-PET/CT may be sensitive in MTC patients with high FDG uptake that signals aggressive disease. ¹⁸F-DOPA is the most sensitive imaging technique to visualize small tumor foci, and is also highly specific in patients with a known MTC, but should be complemented by a CT scan of the chest and by a MRI of the liver to detect small metastases.

Novel Therapeutics for Advanced Differentiated Thyroid Cancer

The current treatments for radioactive iodine (RAI) -refractory differentiated thyroid cancer (DTC) are evolving as cancer genomics are further understood. Multitargeted tyrosine kinase inhibitors are the first-line therapy for symptomatic or progressive disease; however, considerable adverse effects have spurred the development of targeted therapies for redifferentiation of iodine avidity and the treatment of RAI-refractory DTC. Next-generation sequencing allows for the use of tumor-targeted therapeutics, such as MEK1/2, BRAF, RET, and NTRK inhibitors. Immunotherapy is also under investigation as a therapeutic option for this disease.

Diagnostic and Treatment Considerations for Thyroid Cancer in Women of Reproductive Age and the Perinatal Period

Thyroid cancer is one of the most common cancers diagnosed in women of reproductive age and during pregnancy. This leads to important questions about thyroid cancer prognosis and treatment, but also fertility and risk for adverse obstetric and/or fetal and neonatal outcomes. The benefits of thyroid cancer treatment should be weighed against its harms, as various options may adversely impact maternal and fetal health. In the current review, the authors focus on perinatal-specific clinical considerations related to the care of patients with thyroid cancer.

Two-dimensional assembly made up of ZIF-8 particles for the high-efficient capture of the iodine and dyes

The removal of the pollutants from the environment is the need of the environmental protection. ZIF-8 is promising adsorbents, and the construction of ZIF-8 assembly is essential to boost its performance. Here, we showed the easy synthesis of two-dimensional (2D) assembly built by ZIF-8 particles (2D A-ZIF-8) for the high-efficient capture of the iodine (I₂) and dyes. The assembly was synthesized by the controllable reaction of 2-methylimidazole (2-MIM) with 2D Zn-glycerol (Zn-GL) precursor. Time-dependent experiments showed the predominant replacement of GL at outer boundary and then basic plane of the precursor by 2-MIM. The assembly can be synthesized with high output and combined the advantage of large accessible surface of 2D sheets, the plentiful pores of ZIF-8 and enhanced stability of assembly, endowing the large potential as adsorbent. The high adsorption capacity of I₂ (200 wt%) was achieved on A-ZIF-8, while it is about 128 wt% on traditional dodecahedronal ZIF-8. The assembly also showed the excellent adsorption capacity for methyl orange (MO) (46.3 mg g^-1) and methylene blue (MB) (46.5 mg g^-1) at a concentration of 50 mg L^-1. It can be easily separated for reuse benefited from the large size and enhanced stability of assembly.

Enhanced removal of radioactive iodine anions from wastewater using modified bentonite: Experimental and theoretical study

Efficient and cost-effective removal of radioactive iodine anions from contaminated water has become a crucial task and a great challenge for waste treatment and environmental remediation. Herein, we present hexadecylpyridinium chloride monohydrate modified bentonite (HDPy-bent) for the efficient and selective removal of iodine anions (I^- and IO₃^-) from contaminated water. Batch experiments showed that HDPy-bent could remove more than 95% of I^- and IO₃^- within 10 min, and had maximum I^- and IO₃^- adsorption capacities of 80.0 and 50.2 mg/g, respectively. Competitive experiments indicated that HDPy-bent exhibited excellent I^- and IO₃^- selectivity in the excessive presence of common concomitant anions including PO₄^3-, SO₄^2-, HCO₃^-, NO₃^-, Cl^- (maximum mole ratio of anions vs iodine anions was ∼50,000). An anion exchange mechanism was proposed for the selective adsorption of iodine anions. Optimal adsorption structure of HDPy⁺/I^- (IO₃^-) at atomic level and driving forces of the I^- (IO₃^-) adsorption were calculated by density functional theory (DFT) simulations. Moreover, the good durability and reusability of the HDPy-bent has been demonstrated with 5 adsorption-desorption cycles. Dynamic column experiment also demonstrated that HDPy-bent exhibited excellent removal and fractional recovery capabilities towards I^- and IO₃^- from simulated groundwater and environmental water samples. In conclusion, this work presents a promising adsorbent material for the decontamination of radioactive iodine anions from wastewater on a large scale.

Association between exposure to radioactive iodine after the Chernobyl accident and thyroid volume in Belarus 10-15 years later

BACKGROUND

While there is a robust literature on environmental exposure to iodine-131 (131I) in childhood and adolescence and the risk of thyroid cancer and benign nodules, little is known about its effects on thyroid volume.

METHODS

To assess the effect of 131I dose to the thyroid on the volume of the thyroid gland, we examined the data from the baseline screening of the Belarusian-American Cohort Study of residents of Belarus who were exposed to the Chernobyl fallout at ages ≤18 years. Thyroid dose estimates were based on individual thyroid activity measurements made shortly after the accident and dosimetric data from questionnaires obtained 10-15 years later at baseline screening. During baseline screening, thyroid gland volume was assessed from thyroid ultrasound measurements. The association between radiation dose and thyroid volume was modeled using linear regression where radiation dose was expressed with power terms to address non-linearity. The model was adjusted for attained age, sex, and place of residence, and their modifying effects were examined.

RESULTS

The analysis was based on 10,703 subjects. We found a statistically significant positive association between radiation dose and thyroid volume (P < 0.001). Heterogeneity of association was observed by attained age (P < 0.001) with statistically significant association remaining only in the subgroup of ≥18 years at screening (P < 0.001). For this group, increase in dose from 0.0005 to 0.15 Gy was associated with a 1.27 ml (95% CI: 0.46, 2.07) increase in thyroid volume. The estimated effect did not change with increasing doses above 0.15 Gy.

CONCLUSIONS

This is the first study to examine the association between 131I dose to the thyroid gland and thyroid volume in a population of individuals exposed during childhood and systematically screened 10-15 years later. It provides evidence for a moderate statistically significant increase in thyroid volume among those who were ≥ 18 years at screening. Given that this effect was observed at very low doses and was restricted to a narrow dose range, further studies are necessary to better understand the effect.

Radioiodine Refractory Differentiated Thyroid Cancer

Patients with radioactive iodine (RAI) refractory locally advanced or metastatic differentiated thyroid cancer have a poor prognosis. This article reviews the definition of RAI-refractory thyroid cancer and the management approach. Watchful waiting should be considered for patients with asymptomatic and non-progressive disease, while oral targeted agent with tyrosine kinase inhibitors can be considered for patients who are symptomatic or whose disease would cause irreversible complications if treatment has not been initiated. Since these targeted agents only improve disease-free survival and are associated with adverse events, physicians should assess both clinical and tumor factors carefully to decide on the right timing of start of palliative treatment.

Radioactive Iodine for Papillary Thyroid Carcinoma

Radioactive iodine is given after total thyroidectomy for remnant ablation or treatment of residual/metastatic disease. The decision and dose of radioactive iodine should be in a personalized and patient-specific approach, taking account the clinical-pathological features, risk stratification, patient's preference, and facilities of the institutions. We review the principles and use of radioactive iodine in differentiated thyroid cancer.

Meta-Analysis of Randomized Controlled Trials Comparing the Efficacy of Radioactive Iodine Monotherapy versus Radioactive Iodine Therapy and Adjunctive Lithium for the Treatment of Hyperthyroidism

Background: The objective of this article is to evaluate the outcomes in patients undergoing radioactive iodine (RAI) with adjunctive lithium (Li) therapy versus (vs.) RAI therapy alone for the treatment of hyperthyroidism.Methods: A systematic review of the literature was undertaken to analyze clinical trials comparing RAI with adjunctive Li therapy vs. RAI therapy alone for the treatment of hyperthyroidism.Results: Six randomized-controlled trials (RCT) involving 755 patients were analyzed. RAI with adjunctive Li was associated with a significantly higher cure rate for hyperthyroidism when compared to RAI alone. Furthermore, a significantly higher cure rate for hyperthyroidism at 12 months was achieved with RAI and adjunctive Li. Adjuvant Li with RAI for ≤ 7 days showed significantly higher cure rate compared to RAI alone, whereas > 7 days of adjuvant Li with RAI did not show any difference in cure rate compared to RAI alone. RAI with adjunctive Li was associated with a significantly higher cure rate for patients with Graves' disease compared to RAI alone. There was no significant difference between RAI with adjunctive Li and RAI alone for toxic nodular thyroid disorder (toxic nodule and toxic multinodular goiter) and thyroid volume >40 grams and ≤40 grams.Conclusions: RAI with adjunctive Li therapy demonstrated superiority over RAI therapy alone with regards to both curing hyperthyroidism and, reduced time till cure, with a limited side effect profile. A large multicenter RCT is required, and if this confirms the data from these smaller trials, then this could change current practice.

[De-escalation strategies in differentiated thyroid cancer]

Thyroid cancer runs the gamut from indolent micropapillary carcinoma to highly aggressive metastatic disease. Today, using prognostic algorithms, treatment and follow-up can be tailored to each patient in order to decrease overtreatment and over-medicalization of indolent disease. Active surveillance of papillary thyroid carcinoma less than 1cm avoids surgery and thyroid hormone replacement in a large proportion of patient whose tumors remain stable for years. Total thyroidectomy, once a dogma in the treatment of all thyroid cancer, is being supplanted by thyroid lobectomy for low-risk cancers, thereby decreasing the surgical risks involved and improving patients' quality of life. Indications for prophylactic central neck dissection, once mandatory, are now being adapted to the risk of cancer recurrence. Radioactive iodine therapy, also previously mandatory for all, is now only employed according to risk factors and expected outcomes. Follow-up is also being tailored to risk factors for recurrence, with less frequent visits and less use of ultrasound and scintigraphy. For more advanced disease, molecular therapies tailored to somatic mutations are opening opportunities for redifferentiation of aggressive tumors which become amenable to radioactive iodine therapy which carries fewer side effects than other systemic therapies. These advances in the management of thyroid cancer with a personalized approach and de-escalation of treatment and follow-up are improving the way we treat thyroid cancer, avoiding overtreatment and improving patients' quality of life.

A case of the accumulation of 131-iodine in the mammary gland after remnant ablation for papillary thyroid carcinoma on lactating period

The accumulation of 131-iodine is known to occur in the extrathyroidal tissues, such as the salivary glands and the gastrointestinal tract during radioactive iodine therapy. It is considered to be due to the expression of sodium iodide symporter. A 36-year-old lactating female was treated for remnant ablation for papillary thyroid carcinoma (pT1bN1bM0 pStage I) on the condition that she refrained from breastfeeding and was separated from her child and was milked to promote the excretion of 131-iodine until the accumulation disappeared on scintigram imaging. Scintigram showed the decrease and disappearance of the 131-iodine accumulation and the external dose rate was measured and confirmed to have decreased on the day 7 and 14 after the treatment. In conclusion, remnant ablation may be available by milking and separation from the child for 7 to 14 days.

Comprehensive comparison of bismuth and silver functionalized nickel foam composites in capturing radioactive gaseous iodine

Developing an efficient and cheap iodine sorbent is of great practical significance in the modern nuclear industry. In this work, novel bismuth and silver functionalized Ni foam composites as iodine sorption materials (Bi-Ni foam and Ag-Ni foam) were successfully prepared via a simple solvothermal method. Through a series of iodine sorption experiments and characterization methods, iodine capture properties and corresponding sorption mechanism were comprehensively compared and thoroughly revealed. The results show that the core-sheath structure formed by the solvothermal reaction can supply more active sites (Bi⁰ or Ag⁰ particles) for the contact of radioactive iodine gas, thereby improving the sorption capacity of sorbents. Compared with Ag-Ni foam (456 mg/g), Bi-Ni foam exhibits a higher iodine capture capacity (658 mg/g), whereas silver-based material has a faster sorption kinetics. Such excellent sorption performances were attributed to the chemical reaction between Bi⁰/Ag⁰ particles and iodine gas, generating stable BiI₃/AgI. In addition, this type of sorbents inherits the external structure of the Ni foam skeleton, decreasing the physically sorbed iodine, and can be prepared in different shapes and sizes, which is of great practical significance.

Canadian consensus statement on the management of radioactive iodine-resistant differentiated thyroid cancer

Radioactive iodine-resistant differentiated thyroid cancer (RAIRTC) is an aggressive form of thyroid cancer that is uncommon and heterogeneous in its clinical behavior. With the emergence of more effective systemic therapy, the need for guidance in decision-making was recognized and a consensus committee of national experts was assembled. The consensus committee consisted of 13 clinicians involved in treating RAIRTC from across Canada and included endocrinologists, nuclear medicine physicians, surgeons, and radiation and medical oncologists. Domains of interest were identified by consensus, and evidence gathered using systematic reviews. Consensus recommendations for the diagnosis and management of RAIRTC were developed. It was recognized that the rarity of RAIRTC in practice and heterogeneous patterns of thyroid cancer care could limit access to effective therapy for some RAIRTC patients. This document offers guidance to manage RAIRTC patients in a multidisciplinary manner.

The Efficacy and Short- and Long-Term Side Effects of Radioactive Iodine Treatment in Pediatric Graves' Disease: A Systematic Review

BACKGROUND

Graves's disease (GD) is the most common cause of hyperthyroidism. Maximal 30% of pediatric GD patients achieve remission with antithyroid drugs. The majority of patients therefore require definitive treatment. Both thyroidectomy and radioactive iodine (RAI) are often used as definitive treatment for GD. However, data on efficacy and short- and long-term side effects of RAI treatment for pediatric GD are relatively scarce.

METHODS

A systematic review of the literature (PubMed and Embase) was performed to identify studies reporting the efficacy or short- and long-term side effects of RAI treatment in pediatric GD.

RESULTS

Twenty-three studies evaluating 1,283 children and adolescents treated with RAI for GD were included. The treatment goal of RAI treatment changed over time, from trying to achieve euthyroidism in the past to aiming at complete thyroid destruction and subsequent hypothyroidism in the last 3 decades. The reported efficacy of a first RAI treatment when aiming at hypothyroidism ranged from 42.8 to 97.5%, depending on the activity administered. The efficacy seems to increase with higher RAI activities. When aiming at hypothyroidism, both short- and long-term side effects of treatment are very rare. Long-term side effects were mainly seen in patients in whom treatment aimed at achieving euthyroidism.

CONCLUSION

RAI is a safe definitive treatment option for pediatric GD when aiming at complete thyroid destruction. When aiming at hypothyroidism, the efficacy of treatment seems to increase with a higher RAI activity. Prospective studies are needed to determine the optimal RAI dosing regimen in pediatric GD.

Change in Practice of Radioactive Iodine Administration in Differentiated Thyroid Cancer: A Single-Centre Experience

OBJECTIVE

Our study aimed to analyse temporal trends in radioactive iodine (RAI) treatment for thyroid cancer over the past decade; to analyse key factors associated with clinical decisions in RAI dosing; and to confirm lower activities of RAI for low-risk patients were not associated with an increased risk of recurrence.

METHODS

Retrospective analysis of 1,323 patients who received RAI at a quaternary centre in Australia between 2008 and 2018 was performed. Prospectively collected data included age, gender, histology, and American Joint Committee on Cancer stage (7th ed). American Thyroid Association risk was calculated retrospectively.

RESULTS

The median activities of RAI administered to low-risk patients decreased from 3.85 GBq (104 mCi) in 2008-2016 to 2.0 GBq (54 mCi) in 2017-2018. The principal driver of this change was an increased use of 1 GBq (27 mCi) from 1.3% of prescriptions in 2008-2011 to 18.5% in 2017-2018. In patients assigned as low risk per ATA stratification, lower activities of 1 GBq or 2 GBq (27 mCi or 54 mCi) were not associated with an increased risk of recurrence. In patients assigned to intermediate- or high-risk categories who received RAI as adjuvant therapy, there was no difference in risk of recurrence between 4 GBq (108 mCi) and 6 GBq (162 mCi).

CONCLUSIONS

Our data demonstrate an evolution of RAI activities consistent with translation of ATA guidelines into clinical practice. Use of lower RAI activities was not associated with an increase in recurrence in low-risk thyroid cancer patients. Our data also suggest lower RAI activities may be as efficacious for adjuvant therapy in intermediate- and high-risk patients.

Change of Therapeutic Response Classification According to Recombinant Human Thyrotropin-Stimulated Thyroglobulin Measured at Different Time Points in Papillary Thyroid Carcinoma

Purpose

We investigated whether response classification after total thyroidectomy and radioactive iodine (RAI) therapy could be affected by serum levels of recombinant human thyrotropin (rhTSH)-stimulated thyroglobulin (Tg) measured at different time points in a follow-up of patients with papillary thyroid carcinoma (PTC).

Methods

A total of 147 PTC patients underwent serum Tg measurement for response assessment 6 to 24 months after the first RAI therapy. Serum Tg levels were measured at 24 h (D1Tg) and 48-72 h (D2-3Tg) after the 2^nd injection of rhTSH. Responses were classified into three categories based on serum Tg corresponding to the excellent response (ER-Tg), indeterminate response (IR-Tg), and biochemical incomplete response (BIR-Tg). The distribution pattern of response classification based on serum Tg at different time points (D1Tg vs. D2-3Tg) was compared.

Results

Serum D2-3Tg level was higher than D1Tg level (0.339 ng/mL vs. 0.239 ng/mL, P < 0.001). The distribution of response categories was not significantly different between D1Tg-based and D2-3Tg-based classification. However, 8 of 103 (7.8%) patients and 3 of 40 (7.5%) patients initially categorized as ER-Tg and IR-Tg based on D1Tg, respectively, were reclassified to IR-Tg and BIR-Tg based on D2-3Tg, respectively. The optimal cutoff values of D1Tg for the change of response categories were 0.557 ng/mL (from ER-Tg to IR-Tg) and 6.845 ng/mL (from IR-Tg to BIR-Tg).

Conclusion

D1Tg measurement was sufficient to assess the therapeutic response in most patients with low level of D1Tg. Nevertheless, D2-3Tg measurement was still necessary in the patients with D1Tg higher than a certain level as response classification based on D2-3Tg could change.

Usefulness of albumin-globulin ratio as a clinical prognostic factor in patients with thyroid cancer treated with radioiodine

OBJECTIVE

Albumin-globulin ratio (AGR), which is calculated by dividing serum albumin by serum globulin, is considered as a cancer-related inflammation biomarker. Although the prognosis of many solid cancers has been shown to be associated with AGR, there are no studies to demonstrate the association between the prognosis of thyroid cancer and AGR. The purpose of this study is to reveal the relationship between AGR and overall survival (OS) in patients with thyroid cancer who received radioactive iodine therapy (RIT).

METHODS

Eighty-eight patients with thyroid cancer who had received RIT for the first time in our institution were included. The values before RIT were adopted as initial measurements for serum albumin, globulin, and thyroglobulin (Tg) and used for analysis. Patients were divided into two groups based on the AGR value. We analyzed the relationship between clinical factors and treatment outcome.

RESULTS

The median follow-up period was 92.4 months (range: 30.1-173.9 months). The 5-year OS and progression-free survival (PFS) were 94% and 54%, respectively. Seventeen patients (< 65 years, 8; and ≥ 65 years, 9) died during the follow-up period. Low AGR was significantly associated with OS in both univariate and multivariate analyses (p = 0.0059 and p = 0.0120, respectively). As the 5-year OS was as high as 94%, there was no significant difference in survival rate between the two groups during the first 5 years. However, there seemed to be a remarkable difference in 10 years after the first RIT. On the other hand, Tg was significantly associated with PFS in both univariate and multivariate analyses (p = 0.0016 and p = 0.0441, respectively). In patients under the age of 65, the PFS rate was significantly lower in the low AGR group (p < 0.0001), while there was no difference in PFS rate between the two AGR groups in patients aged 65 years or older.

CONCLUSIONS

AGR may be used as a prognostic factor in relatively younger patients with thyroid cancer treated with radioiodine, while it may be less useful in the older. Overall, it may be an independent prognostic factor for long-term survival in those with thyroid cancer.

Impact of expert review of histological diagnosis of papillary and follicular thyroid cancer

PURPOSE

Histologic and pTNM classification of differentiated thyroid cancer (DTC) is mandatory to assess risk of relapse, risk of death, and radioactive iodine administration. The impact of an expert central review of external pathology reports has not yet been reported.

METHODS

Monocentric retrospective study to evaluate the difference between initial and second-opinion histopathologic diagnosis for DTC patients referred for post-operative radioactive iodine administration between January 2014 and December 2016. We evaluated major discordance (change of diagnosis from malignant to benign or in main histological subtype or a description of aggressive pathological subtypes), minor discordance (change in histological subtype or description of an aggressive component, multifocality or extrathyroidal extension), and change in ATA classification.

RESULTS

A second-opinion histological diagnosis was available for 199 patients. A major discordance was observed in 42 (21%) cases (changes in malignancy in 4 cases, changes in main histological subtype in 22, changes in aggressive pathology variants of PTC in 16). One hundred and four minor discordances were observed regarding 92 patients. These histopathological changes led to changes in the ATA 2015 risk stratification classification in 61 (31%) of cases. There were no predictive factors of major/minor histologic changes or ATA risk stratification changes.

CONCLUSION

Expert central review of pathology has an impact on the 2015 ATA risk stratification classification that can lead to changes in the management of patients with differentiated thyroid cancer.

Risk and outcome of subsequent malignancies after radioactive iodine treatment in differentiated thyroid cancer patients

BACKGROUND

We identified differentiated thyroid cancer (DTC) survivors from SEER registries and performed Poisson regression to calculate the relative risks (RRs) of subsequent malignancies (SMs) by different sites associated with radioactive iodine (RAI) treatment, and the attributable risk proportion of RAI for developing different SMs.

RESULTS

We identified 4628 of 104,026 DTC patients developing a SM after two years of their DTC diagnosis, with a medium follow-up time of 113 months. The adjusted RRs of developing SM associated with RAI varied from 0.98 (0.58-1.65) for neurologic SMs to 1.37 (1.13-1.66) for hematologic SMs. The RRs of developing all cancer combined SMs generally increased with age at DTC diagnosis and decreased with the latency time. We estimated that the attributable risk proportion of RAI treatment is only 0.9% for all cancer combined SMs and 20% for hematologic SMs, which is the highest among all SMs. The tumor features and mortalities in patients treated with and without RAI are generally comparable.

CONCLUSION

With the large population based analyses, we concluded that a low percentage of DTC survivors would develop SMs during their follow-up. Although the adjusted RR of SMs development increased slightly in patients receiving RAI, the attributable risk proportion associated with RAI was low, suggesting the absolute number of SMs induced by RAI in DTC survivors would be low. The attributable risk proportion of RAI treatment is the highest in hematological SMs, but when in consideration of its low incidence among all DTC survivors, the absolute number of hematological SMs was low.

Mass spectrometry - based imaging techniques for iodine-127 and iodine-129 detection and localization in the brown alga Laminaria digitata

129I is one of the main radioisotopes of iodine derived from the nuclear fuel cycle that can be found sustainably in the environment due to its long half-life. In coastal marine environment, brown macroalgae, such laminariales (or kelps), are known to naturally feature highest rates of iodine accumulation, and to be an important source of biogenic volatile iodinated compounds released to the atmosphere. These seaweeds are therefore likely to be significantly marked by but also potential vectors of radioactive iodine. In order to better understand the chemical and isotopic speciation of iodine in brown algal tissues, we combined mass spectrometry-based imaging approaches in natural samples of Laminaria digitata young sporophytes, collected at two different locations along the south coast of the English Channel (Roscoff and Goury). Laser desorption ionization (LDI) and desorption electrospray-ionization techniques (DESI), coupled with mass spectrometry, confirmed the predominance of inorganic I- species on the surface of fresh algae, and a peripheral iodine localization when applied on micro-sections. Moreover, radioactive isotope 129I was not detected on plantlet surface or in stipe sections of algal samples collected near Roscoff but was detected in L. digitata samples collected at Goury, near La Hague, where controlled liquid radioactive discharges from the ORANO La Hague reprocessing plant occur. At the subcellular scale, cryo-fixed micro-sections of algal blade samples from both sites were further analyzed by secondary ion mass spectrometry (nano-SIMS), leading to similar results. Even if the signal detected for 129I was much weaker than for 127I in samples from Goury, the chemical imaging revealed some differences in extracellular distribution between radioactive and stable iodine isotopes. Altogether LDI and nano-SIMS are complementary and powerful techniques for the detection and localization of iodine isotopes in algal samples, and for a better understanding of radioactive and stable iodine uptake mechanisms in the marine environment.