Adverse effects of radioactive iodine-131 treatment for differentiated thyroid carcinoma

Early and long-term responses of intestinal microbiota and metabolites to 131I treatment in differentiated thyroid cancer patients

BACKGROUND

Multiple high doses of 131I therapy in patients with differentiated thyroid cancer (DTC) might disrupt the balance of gut microbiota and metabolites. This study aimed to investigate the alterations of intestinal bacteria and metabolism over two courses of 131I therapy, explore the interactions, and construct diagnostic models reflecting enteric microecology based on 131I therapy.

METHODS

A total of 81 patients were recruited for the first 131I therapy (131I-1st), among whom 16 received a second course (131I-2nd) after half a year. Fecal samples were collected 1 day before (Pre-131I-1st/2nd) and 3 days after (Post-131I-1st/2nd) 131I therapy for microbiome (16S rRNA gene sequencing) and metabolomic (LC-MS/MS) analyses.

RESULTS

A total of six microbial genera and 11 fecal metabolites enriched in three pathways were identified to show significant differences between Pre-131I-1st and other groups throughout the two courses of 131I treatment. In the Post-131I-1st group, the beneficial bacteria Bifidobacterium, Lachnoclostridium, uncultured_bacterium_f_Lachnospiraceae, and Lachnospiraceae_UCG004 were abundant and the radiation-sensitive pathways of linoleic acid (LA), arachidonic acid, and tryptophan metabolism were inhibited compared with the Pre-131I-1st group. Compared with the Pre-131I-1st group, the Pre-131I-2nd group exhibited a reduced diversity of flora and differentially expressed metabolites, with a low abundance of beneficial bacteria and dysregulated radiation-sensitive pathways. However, less significant differences in microbiota and metabolites were found between the Pre/Post-131I-2nd groups compared with those between the Pre/Post-131I-1st groups. A complex co-occurrence was observed between 6 genera and 11 metabolites, with Lachnoclostridium, Lachnospiraceae_UCG004, Escherichia-Shigella, and LA-related metabolites contributing the most. Furthermore, combined diagnostic models of charactered bacteria and metabolites answered well in the early, long-term, and dose-dependent responses for 131I therapy.

CONCLUSIONS

Different stages of 131I therapy exert various effects on gut microecology, which play an essential role in regulating radiotoxicity and predicting the therapeutic response.

Salivary, lacrimal and nasal (SALANS) measure to assess side effects following radioactive iodine treatment: development, psychometric properties, and factor structure

PURPOSE

This study aimed to develop and psychometrically evaluate a patient-reported outcome measure (PROM), SAlivary, LAcrimal, NaSal (SALANS), to document patients' symptoms after radioactive iodine (RAI) treatment for differentiated thyroid cancer (DTC).

METHODS

We generated and iteratively revised SALANS items based on expert input, focus group discussions and feedback from cognitive testing (n = 17). We administered an initial SALANS measure with 39 items to patients diagnosed with DTC in the past two years (n = 105). Exploratory factor analysis (EFA) examined the factor structure of the SALANS items. We assessed the consistency reliability and related the total and subscale scores of the final SALANS to existing PROMs to assess validity.

RESULTS

The final SALANS consisted of 33 items and six subscales (sialadenitis, taste, xerostomia, dry eyes, epiphora, and nasal) with six factors extracted by EFA. The six subscales demonstrated good internal reliability (α range = 0.87-0.92). The SALANS total score showed good convergent validity with the Xerostomia Inventory (r = 0.86) and good discriminant validity with a measure of spirituality (r =  - 0.05). The mean SALANS total score was significantly higher (d = 0.5, p < 0.04) among patients who had RAI compared to those who did not have RAI.

CONCLUSION

Preliminary evidence suggests that SALANS is a novel and reliable PROM to assess the type and frequency all symptoms experienced after RAI treatment for DTC. Future work is needed to further validate and develop the scale.

Disrupted gut microecology after high-dose 131I therapy and radioprotective effects of arachidonic acid supplementation

BACKGROUND

Despite the potential radiotoxicity in differentiated thyroid cancer (DTC) patients with high-dose 131I therapy, the alterations and regulatory mechanisms dependent on intestinal microecology remain poorly understood. We aimed to identify the characteristics of the gut microbiota and metabolites in DTC patients suffering from high-dose 131I therapy and explore the radioprotective mechanisms underlying arachidonic acid (ARA) treatment.

METHODS

A total of 102 patients with DTC were recruited, with fecal samples collected before and after 131I therapy for microbiome and untargeted and targeted metabolomic analyses. Mice were exposed to total body irradiation with ARA replenishment and antibiotic pretreatment and were subjected to metagenomic, metabolomic, and proteomic analyses.

RESULTS

131I therapy significantly changed the structure of gut microbiota and metabolite composition in patients with DTC. Lachnospiraceae were the most dominant bacteria after 131I treatment, and metabolites with decreased levels and pathways related to ARA and linoleic acid were observed. In an irradiation mouse model, ARA supplementation not only improved quality of life and recovered hematopoietic and gastrointestinal systems but also ameliorated oxidative stress and inflammation and preserved enteric microecology composition. Additionally, antibiotic intervention eliminated the radioprotective effects of ARA. Proteomic analysis and ursolic acid pretreatment showed that ARA therapy greatly influenced intestinal lipid metabolism in mice subjected to irradiation by upregulating the expression of hydroxy-3-methylglutaryl-coenzyme A synthase 1.

CONCLUSION

These findings highlight that ARA, as a key metabolite, substantially contributes to radioprotection. Our study provides novel insights into the pivotal role that the microbiota-metabolite axis plays in radionuclide protection and offers effective biological targets for treating radiation-induced adverse effects.

Update on lacrimal apparatus dysfunction associated with differentiated thyroid cancer after I-131 therapy

PURPOSE

The most prevalent lacrimal apparatus dysfunctions associated with differentiated thyroid cancer(DTC) after I-131 therapy are dry eye and nasolacrimal duct obstruction(NLDO), leading to ocular discomfort and lower quality of life for patients. It is crucial to diagnose and manage lacrimal apparatus dysfunction associated with I-131 therapy for DTC. Therefore, this review aims to comprehensively summarize and analyze the advances in mechanisms and therapeutic options underlying lacrimal apparatus dysfunction induced by I-131 therapy for DTC.

METHODS

A comprehensive search of CNKI, PubMed, and Wed of Science was performed from the database to December of 2023. Key search terms were "Thyroid cancer", "I-131", "Complications", "Dry eye", "Epiphora", "Tear", "Nasolacrimal duct" and "NLDO".

RESULTS

The research indicates that I-131 therapy for DTC causes damage to the lacrimal glands and nasolacrimal duct system, resulting in symptoms such as dry eye, epiphora, and mucoid secretions. Moreover, recent research has focused on exploring relevant risk factors of the condition and experimental and clinical treatments. However, there is some controversy regarding the mechanisms involved, whether it is due to the passive flow of I-131 in tears, active uptake of I-131 by the sodium-iodide symporter (NIS) in the lacrimal sac and nasolacrimal duct, or secondary metabolic and hormonal disturbances caused by I-131.

CONCLUSION

It is crucial for early detection and preventive measures by ophthalmologists and the need for further studies to elucidate the mechanisms underlying the disease.

An age-and sex-matched postoperative therapy should be required in thyroid papillary carcinoma

Background and purpose

Thyroid papillary carcinoma (PTC) had a high possibility of recurrence after surgery, and thyroid stimulating hormone (TSH) suppression and radioactive iodine (131I) were used for postoperative therapy. This study explored the potential mechanism of lymph node metastasis (LNM) and aimed to develop differentiated treatments for PTC.

Method

This study explored the risk factors of lymph node metastasis in PTC by analyzing the clinical information of 2073 cases. The Cancer Genome Atlas Thyroid Cancer (TCGA-THCA) and the Gene Expression Omnibus (GEO) databases of gene expression were analyzed to identify the interrelationships between gene expression to phenotype.

Results

Analyzing clinical data, we found that male gender, younger age, larger tumor size, and extra-thyroidal extension (ETE) were risk significant risk factors for lymph node metastasis(P<0.05). Conversely, thyroid function parameters such as TSH, FT3, FT4, TSH/FT3, and TSH/FT4 didn't correlate with LNM(P>0.05), and TSH levels were observed to be higher in females(P<0.05). Gene expression analysis revealed that SLC5A5 was down-regulated in males, younger individuals, and those with lymph node metastasis, and a lower level of SLC5A5 was associated with a worse disease-free survival(P<0.05). Additionally, our examination of single-cell RNA sequencing (scRNA-seq) data indicated that SLC5A5 expression was reduced in tumors and lymph node metastasis samples, correlating positively with the expression of TSHR.

Conclusion

The impact of TSH on PTC behavior remained unclear, while the capacity for absorbing 131I in dependence on SLC5A5 showed variations across different genders and ages. We conclude that postoperative treatment of PTC should take into account the differences caused by gender and age.

The prophylactic antiemetic therapies in management of differentiated thyroid cancer patients with radioactive iodine therapy: a single-center, non-randomized clinical trial

Objective

The present study was to investigate three different single-drug regimens to show which was more effective to reduce radioactive iodine therapy (RAI) associated nausea and vomiting, and to compare the occurrence of long-term gastrointestinal diseases after RAI therapy.

Method

We performed a single-center, non-randomized clinical trial among patients who underwent RAI therapy from March 2016 to July 2022. Enrolled patients were divided into four cohorts based on the date of the treatment. cohort 1, with no preventive antiemetics; cohort 2, received 20 mg of pantoprazole per day for 3 days; cohort 3, received a 10 mg metoclopramide tablet two times daily for 3 days; cohort 4, oral ondansetron, 8 mg, twice daily for 3 days. The primary endpoints were proportion of patients who experience vomiting episodes and nausea during the 7-day hospital period. Secondary end points included Functional Living Index Emesis (FLIE) quality-of life questionnaires and the occurrence of gastrointestinal diseases.

Results

A total of 1755 patients were analyzed, comprised of 1299 (74.0%) women and 456 (26.0%) men, with a median age of 44 years (range 18-78 years). The characteristics of patient were similar within the four groups. 465 (26.4%) patients developed RAI-associated nausea, and 186 (14.4%) patients developed RAI-associated vomiting. The rate of nausea was significantly decreased in the patients who were taking ondansetron when compared with the other cohorts (P<0.05), while the rate of vomiting (≥6 episodes) was slightly lower. As secondary endpoint, FLIE measures ondansetron scored highly compared to other cohorts, from baseline (mean score of 110.53 ± 17.54) to day 7 (mean score of 105.56 ± 12.48). In addition, 48 (2.7%) patients were found to be with gastrointestinal diseases at the end of one year follow up. Multiple RAI therapy and higher dose of I-131 per body weight revealed a significantly independent risk factors of developing gastrointestinal disorders.

Conclusions

In conclusion, the present study demonstrated that short-term ondansetron could be an effective prophylactic agent in controlling RAI-associated nausea and vomiting. Furthermore, the risk of developing gastrointestinal disorders was significantly higher for patients with multiple RAI therapy and higher dose of I-131 per body weight.

How Radioactive Iodine Treatment Affects the Retina

Objective  The aim of this study was to quantitatively assess the macular and retinal nerve fiber layer thicknesses in patients with hyperthyroidism and thyroid cancer undergoing radioactive iodine (RAI) therapy. Study Design  This prospective study was conducted in accordance with the principles of the Declaration of Helsinki and approved by the Bagcilar Training and Research Hospital Clinical Research Ethics Committee. Written informed consent was obtained from the patients following a detailed explanation of the study objectives and protocol. Patient selection was randomized. Patients scheduled for RAI treatment in the Nuclear Medicine Clinic were referred to the ophthalmology clinic, respectively. Patients without additional ocular pathology were included in the study. Methods  All patients had received RAI therapy using Iodine-131 for hyperthyroidism or thyroid cancer. A complete ophthalmological examination and measurement of macular and retinal nerve fiber layer thickness using optical coherence tomography were performed on all patients before and at the first and sixth months and in first year after RAI treatment. The results were prospectively evaluated. Results  The study included 80 eyes of 40 patients. The hyperthyroid group was group 1, and the thyroid cancer group was group 2. There were 25 patients in group 1 and 15 patients in group 2. The mean age was 43.76 ± 11.85 years (range: 22-65 years) in group 1 and 39.87 ± 9.13 years (range: 30-58 years) in group 2. There was no significant difference between the two groups regarding age and sex ( p  > 0.05). In both groups, no significant difference was found in the macular thickness and retinal nerve fiber layer thicknesses values obtained in both eyes before and after the RAI treatment. Conclusion  As a result of our study, we observed that RAI intake did not harm the retinal layer.

Comparative Analysis of Morphological and Functional Effects of 225Ac- and 177Lu-PSMA Radioligand Therapies (RLTs) on Salivary Glands

Most Prostate Specific Membrane Antigens (PSMAs) targeting small molecules accumulate in the salivary glands (SGs), raising concerns about SG toxicity, especially after repeated therapies or therapy with 225Ac-labeled ligands. SG toxicity is assessed clinically by the severity of patient-reported xerostomia, but this parameter can be challenging to objectively quantify. Therefore, we explored the feasibility of using SG volume as a biomarker for toxicity. In 21 patients with late-stage metastatic resistant prostate cancer (mCRPC), the PSMA volume and ligand uptake of SG were analyzed retrospectively before and after two cycles of 177Lu-PSMA (LuPSMA; cohort A) and before and after one cycle of 225Ac-PSMA-617 (AcPSMA, cohort B). Mean Volume-SG in cohort A was 59 ± 13 vs. 54 ± 16 mL (-10%, p = 0.4), and in cohort B, it was 50 ± 13 vs. 40 ± 11 mL (-20%, p = 0.007), respectively. A statistically significant decrease in the activity concentration in the SG was only observed in group B (SUVmean: 9.2 ± 2.8 vs. 5.3 ± 1.8, p < 0.0001; vs. A: SUVmean: 11.2 ± 3.3 vs. 11.1 ± 3.5, p = 0.8). SG volume and PSMA-ligand uptake are promising markers to monitor the SG toxicity after a PSMA RLT.

Robotic system for magnetic resonance imaging-guided focused ultrasound treatment of thyroid nodules

BACKGROUND

Herein, a robotic system offering Magnetic Resonance-guided Focused Ultrasound (MRgFUS) therapy of thyroid nodules was developed.

METHODS

The robotic system offers linear motion in 2 PC-controlled axes that navigate a 3 MHz single-element focused transducer. The system, through a C-arm structure attaches to the table of Magnetic Resonance Imaging (MRI) scanners and couples to the neck of patients lying in the supine position. The MRI compatibility of the developed system was assessed inside a 3 T scanner. Benchtop and MRI feasibility studies evaluating the heating performance of the system were executed on excised pork tissue and on homogeneous and thyroid model agar-based phantoms.

RESULTS

The MRI compatibility of the system was successfully established. Grid sonications executed using robotic motion inflicted discrete and overlapping lesions on the excised tissue, while magnetic resonance (MR) thermometry successfully monitored thermal heating in agar-based phantoms.

CONCLUSIONS

The developed system was found to be efficient with ex-vivo evaluation. The system can perform clinical MRgFUS therapy of thyroid nodules and other shallow targets after further in-vivo evaluation.

Efficacy and safety of postoperative levothyroxine sodium tablets for improving serum thyroid hormone levels and tumor marker levels in patients with thyroid tumors

Levothyroxine tablet has been used for improving serum thyroid hormones. Despite its efficacy, there has been a persistent recurrence. We aimed to evaluate the efficacy of levothyroxine regimen (administered as sodium tablets or liquid) therapy, including the regime in combination with other thyroxine hormones, to determine its effectiveness and safety regarding thyroid tumor patient outcomes. An electronic search of the online databases (PubMed, EMBASE, and Web of Science) was performed in duplicate independently by two authors (SSK and LPY) to identify any potential studies published in the English language from January 2002 to October 2022. The records were retrieved using keywords and MeSH terms. The Cochrane risk of bias tool in the Review Manager (RevMan software version 5.4.) was used to evaluate the risk of bias in the included studies.  A total of 18 quality studies were reported on levothyroxine tablets. Results showed that liquid levothyroxine was more efficient than tablet levothyroxine. Further results showed that levothyroxine in combination with L-T3 or I-131 was more effective than L-T4 tablet monotherapy for improving thyroid cancer hormones. Levothyroxine tablet monotherapy is less efficient than liquid levothyroxine and/or levothyroxine combined therapy. This research recommends future research using larger randomized controlled studies.

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.

Advances in Antioxidant Applications for Combating 131I Side Effects in Thyroid Cancer Treatment

Thyroid cancer is the most common endocrine cancer, and its prevalence has been increasing for decades. Approx. 95% of differentiated thyroid carcinomas are treated using ¹³¹iodine (¹³¹I), a radionuclide with a half-life of 8 days, to achieve optimal thyroid residual ablation following thyroidectomy. However, while ¹³¹I is highly enriched in eliminating thyroid tissue, it can also retain and damage other body parts (salivary glands, liver, etc.) without selectivity, and even trigger salivary gland dysfunction, secondary cancer, and other side effects. A significant amount of data suggests that the primary mechanism for these side effects is the excessive production of reactive oxygen species, causing a severe imbalance of oxidant/antioxidant in the cellular components, resulting in secondary DNA damage and abnormal vascular permeability. Antioxidants are substances that are capable of binding free radicals and reducing or preventing the oxidation of the substrate in a significant way. These compounds can help prevent damage caused by free radicals, which can attack lipids, protein amino acids, polyunsaturated fatty acids, and double bonds of DNA bases. Based on this, the rational utilization of the free radical scavenging function of antioxidants to maximize a reduction in ¹³¹I side effects is a promising medical strategy. This review provides an overview of the side effects of ¹³¹I, the mechanisms by which ¹³¹I causes oxidative stress-mediated damage, and the potential of natural and synthetic antioxidants in ameliorating the side effects of ¹³¹I. Finally, the disadvantages of the clinical application of antioxidants and their improving strategies are prospected. Clinicians and nursing staff can use this information to alleviate ¹³¹I side effects in the future, both effectively and reasonably.

Dependence of radioactive iodine-131 capture by the lacrimal ducts on the tear production level

Purpose

Secondary acquired lacrimal duct obstruction (SALDO) is one of the complications of radioiodine therapy. SALDO is formed a few months after therapy if there is a sufficient uptake of radioactive iodine by the nasolacrimal duct. To date, risk factors leading to SALDO are unclear. The objective was to determine the correlation between the tear production level and radioactive iodine-131 uptake in the lacrimal ducts.

Methods

Basal and reflex tear production was studied in 64 eyes prior to the therapy with radioactive iodine-131 after drug-induced hypothyroidism. The condition of the ocular surface was assessed using the Ocular Surface Disease Index (OSDI) questionnaire. Seventy-two hours after the radioactive iodine therapy, scintigraphy was performed, which determined the presence or absence of iodine-131 in the lacrimal ducts. T-statistics and the Mann-Whitney criterion were used to identify the differences between the groups. The differences were considered significant at P ≤ 0.05. The current tear production level in patients receiving radioiodine therapy was determined using a mathematical model.

Results

A statistically significant difference between the basal (p = 0.044) and reflex (p = 0.015) tear production levels was found in cases with and without iodine-131 uptake by the lacrimal ducts. The probable current tear production level corresponds to the sum of basal and 10-20% of reflex tear production. The uptake of iodine-131 was found regardless of the OSDI results.

Conclusion

The probability of iodine-131 uptake by the lacrimal ducts rises as the tear production level increases.

Multi-Omics and Management of Follicular Carcinoma of the Thyroid

Follicular thyroid carcinoma (FTC) is the second most common cancer of the thyroid gland, accounting for up to 20% of all primary malignant tumors in iodine-replete areas. The diagnostic work-up, staging, risk stratification, management, and follow-up strategies in patients who have FTC are modeled after those of papillary thyroid carcinoma (PTC), even though FTC is more aggressive. FTC has a greater propensity for haematogenous metastasis than PTC. Furthermore, FTC is a phenotypically and genotypically heterogeneous disease. The diagnosis and identification of markers of an aggressive FTC depend on the expertise and thoroughness of pathologists during histopathological analysis. An untreated or metastatic FTC is likely to de-differentiate and become poorly differentiated or undifferentiated and resistant to standard treatment. While thyroid lobectomy is adequate for the treatment of selected patients who have low-risk FTC, it is not advisable for patients whose tumor is larger than 4 cm in diameter or has extensive extra-thyroidal extension. Lobectomy is also not adequate for tumors that have aggressive mutations. Although the prognosis for over 80% of PTC and FTC is good, nearly 20% of the tumors behave aggressively. The introduction of radiomics, pathomics, genomics, transcriptomics, metabolomics, and liquid biopsy have led to improvements in the understanding of tumorigenesis, progression, treatment response, and prognostication of thyroid cancer. The article reviews the challenges that are encountered during the diagnostic work-up, staging, risk stratification, management, and follow-up of patients who have FTC. How the application of multi-omics can strengthen decision-making during the management of follicular carcinoma is also discussed.

The efficacy of adjuvant radioactive iodine after reoperation in patients with persistent or recurrent differentiated thyroid cancer: a systematic review

OBJECTIVE

The effectiveness of adjuvant radioiodine (RAI) after reoperation in patients with persistent or recurrent differentiated thyroid cancer (DTC) is controversial. Although various organizations recognize that strong evidence for the use of RAI is lacking, they continue to recommend the use of adjuvant RAI therapy for select groups of patients. This is concerning as RAI therapy has potential side effects such as gastrointestinal symptoms, bone marrow suppression, and gonadal damage.

METHODS

Four electronic databases were systematically searched for randomized trials or observational studies that examined the outcomes of adjuvant RAI after reoperation for recurrent DTC, among patients of any age. The baseline characteristics, treatment response, disease progression, and overall survival of these studies were synthesized and reported. A meta-analysis of the use of RAI on progression-free survival was also performed.

RESULTS

Six observational studies, comprising a combined cohort of 437 patients who underwent reoperation, were included from 1212 records. Adjuvant RAI after reoperation in recurrent DTC was not associated with longer progression-free or overall survival. There was also no association of RAI with excellent structural or biochemical treatment response, lower thyroglobulin levels, nor a lower rate of second recurrence or distant metastases.

CONCLUSIONS

Adjuvant RAI after reoperation in recurrent DTC was not associated with improved cancer or treatment-related outcomes. However, as the included studies were of inadequate quality, there is an urgent need for randomized trials and well-analyzed cohort studies. Physicians should exercise clinical judgment to prescribe adjuvant RAI for only selected, high-risk patients.

Role of 131I in low-risk differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is the most frequent endocrine neoplasm, with an increase in recent decades. Papillary carcinoma is the most frequent histological subtype and a large number of cases are related to tumors of small size and with little clinical repercussion, detected incidentally or as a consequence of the availability of diagnostic techniques. The "good prognosis" of the majority of cases has maintained for years the controversy in the approach to these patients, especially in two basic aspects of the therapeutic protocol: surgery and the administration of radioiodine. While in metastatic and high-risk patients, the administration of ¹³¹I therapy is widely accepted, in intermediate-low risk patients its use is highly questioned. In this paper we review the available evidence on radioiodine therapy in low-risk patients.

Association between thyroid cancer and cardiovascular disease: A meta-analysis

Objective

To determine the association between thyroid cancer and coronary artery disease, atrial fibrillation, cerebrovascular disease, and cardiovascular disease mortality.

Methods

The PubMed, Embase, and Cochrane Library databases were searched for eligible studies from inception to September 22, 2022. Keywords included "thyroid cancer", "atrial fibrillation", "coronary artery disease", "cerebrovascular disease", and "mortality". Primary outcomes included the incidence of coronary artery disease, cerebrovascular disease, atrial fibrillation, and cardiovascular disease mortality among patients with thyroid cancer. Secondary outcomes included cardiovascular disease events among those with thyroid cancer that received or did not receive radioactive iodine or lenvatinib. Estimates were pooled using fixed- and random-effects meta-analysis.

Results

A total of 771,220 patients who underwent thyroidectomy in 15 studies were included. Risk for cerebrovascular disease (risk ratio [RR] 1.15 [95% confidence interval (CI) 1.10-1.21]) and atrial fibrillation [RR 1.59 (95% CI: 1.45-1.73)] were significantly increased. Risk for coronary artery disease was significantly increased [RR 1.12 (95% CI: 1.08-1.17)] in the common effect model. Cardiovascular disease mortality associated with thyroid cancer was not significant [RR 0.93 (95% CI: 0.59-1.45)]. Radioactive iodine had a neutral effect on cardiovascular disease [RR 1.00 (95% CI: 0.87-1.16)], and there was no beneficial nor harmful effect among different RAI doses.

Conclusions

Thyroid cancer was significantly associated with a higher risk for cerebrovascular disease and atrial fibrillation; however, the hazard risk was not different between patients with and without radioactive iodine treatment. Thyroid cancer treatment should be individualized considering the potential harms and benefits to cardiovascular health.

Paediatric differentiated thyroid carcinoma: a UK National Clinical Practice Consensus Guideline

This guideline is written as a reference document for clinicians presented with the challenge of managing paediatric patients with differentiated thyroid carcinoma up to the age of 19 years. Care of paediatric patients with differentiated thyroid carcinoma differs in key aspects from that of adults, and there have been several recent developments in the care pathways for this condition; this guideline has sought to identify and attend to these areas. It addresses the presentation, clinical assessment, diagnosis, management (both surgical and medical), genetic counselling, follow-up and prognosis of affected patients. The guideline development group formed of a multi-disciplinary panel of sub-speciality experts carried out a systematic primary literature review and Delphi Consensus exercise. The guideline was developed in accordance with The Appraisal of Guidelines Research and Evaluation Instrument II criteria, with input from stakeholders including charities and patient groups. Based on scientific evidence and expert opinion, 58 recommendations have been collected to produce a clear, pragmatic set of management guidelines. It is intended as an evidence base for future optimal management and to improve the quality of clinical care of paediatric patients with differentiated thyroid carcinoma.

Ionizing Radiation from Radiopharmaceuticals and the Human Gut Microbiota: An Ex Vivo Approach

This study aimed to determine the effect of three widely used radiopharmaceuticals with intestinal excretion on selected relevant bacteria that are part of the human gut microbiota, using an ex vivo approach. Fecal samples obtained from healthy volunteers were analyzed. Each sample was divided into four smaller aliquots. One served as the non-irradiated control. The other three were homogenized with three radiopharmaceutical solutions ([¹³¹I]NaI, [^99mTc]NaTcO₄, and [²²³Ra]RaCl₂). Relative quantification of each taxa was determined by the 2^−ΔΔC method, using the ribosomal gene 16S as an internal control (primers 534/385). Twelve fecal samples were analysed: three controls and nine irradiated. Our experiment showed fold changes in all analyzed taxa with all radiopharmaceuticals, but results were more significant with I-131, ranging from 1.87–83.58; whereas no relevant differences were found with Tc-99m and Ra-223, ranging from 0.98–1.58 and 0.83–1.97, respectively. This study corroborates limited existing research on how ionizing radiation changes the gut microbiota composition, providing novel data regarding the ex vivo effect of radiopharmaceuticals. Our findings justify the need for future larger scale projects.

Clinical Efficacy of Levothyroxine Sodium plus I 131 in the Treatment of Patients with Thyroidectomy and Its Effect on the Levels of Thyroglobulin and Thyrotropin

Objective

This study was to evaluate the clinical efficacy of levothyroxine sodium tablets combined with I 131 in the treatment of patients after thyroidectomy and the effect on thyroglobulin (Tg) and thyroid stimulating hormone (TSH) levels.

Methods

80 patients with differentiated thyroid cancer who required thyroidectomy after surgery between July 2019 and January 2021 were recruited for prospective study, 40 patients in the control group received levothyroxine sodium tablets, and 40 patients in the experimental group received levothyroxine sodium treatment plus I 131 treatment. Treatment effect, serum Tg and TSH levels, and relapse were measured.

Results

The removal rate of residual thyroid tissue in the experimental group (87.50%) was significantly higher than that in the control group (57.50%) (P < 0.05). Levothyroxine sodium tablets plus I 131 was associated with a significantly higher efficacy versus levothyroxine sodium tablets (P < 0.05). There were no significant differences in the serum Tg levels between the two groups before treatment (P > 0.05). After treatment, the serum Tg levels in both groups were significantly decreased, and levothyroxine sodium tablets plus I 131 resulted in a significantly lower Tg level versus levothyroxine sodium tablets (P < 0.05). Before treatment, the two groups showed similar TSH levels (P > 0.05). After treatment, patients receiving levothyroxine sodium tablets plus I 131 had a significantly greater increase in the TSH levels versus levothyroxine sodium tablets (P < 0.05). The recurrence rate of the experimental group was lower than that of the control group (P < 0.05).

Conclusion

Levothyroxine sodium tablets plus I 131 for post-operative patients with differentiated thyroid cancer enhance the removal rate of residual thyroid tissue, effectively reduce serum Tg level, and increase TSH level, with significant therapeutic effects, low recurrence rates, and a high safety profile.

Risk factors of SARS-CoV-2 infection in cancer patients pre- and post-vaccination

Background

Severe complications from COVID-19 and poor responses to SARS-CoV-2 vaccination were commonly reported in cancer patients compared to those without cancer. Therefore, the identification of predisposing factors to SARS-CoV-2 infection in cancer patients would assist in the prevention of COVID-19 and improve vaccination strategies. The literature lacks reports on this topic from the Kingdom of Saudi Arabia (KSA). Therefore, we studied clinical and laboratory data of 139 cancer patients from King Abdulaziz Medical City, Riyadh, KSA.

Methods

The cancer patients fall into three categories; (i) uninfected with SARS-CoV-2 pre-vaccination and remained uninfected post-vaccination (control group; n = 114; 81%), (ii) pre-vaccination infected group (n = 16; 11%), or (iii) post-vaccination infected group (n = 9; 6%). Next, the clinical and lab data of the three groups of patients were investigated.

Results

Comorbidity factors like diabetes and hemodialysis were associated with the risk of infection in cancer patients before the vaccination (p<0.05). In contrast to breast cancer, papillary thyroid cancer was more prevalent in the infected patients pre- and post-vaccination (p<0.05). Pre-vaccination infected group had earlier cancer stages compared with the control group (p = 0.01). On the other hand, combined therapy was less commonly administrated to the infected groups versus the control group (p<0.05). Neutrophil to lymphocyte ratio was lower in the post-vaccination infected group compared to the control group (p = 0.01).

Conclusion

Collectively, this is the first study from KSA to report potential risk factors of SARS-CoV-2 infection in cancer patients pre- and post-vaccination. Further investigations on these risk factors in a larger cohort are worthwhile to draw a definitive conclusion about their roles in predisposing cancer patients to the infection.

Second primary malignancies induced by radioactive iodine treatment of differentiated thyroid carcinoma - a critical review and evaluation of the existing evidence

PURPOSE

Concern is growing about long-term side effects of differentiated thyroid cancer treatment, most notably radioactive iodine (RAI) therapy. However, published studies on the subject have had heterogeneous cohorts and conflicting results. This review seeks to provide an updated evaluation of published evidence, and to elucidate the risk of second primary malignancies (SPMs), especially secondary hematologic malignancies (SHMs), attributable to RAI therapy.

METHODS

An extensive literature search was performed in Ovid MEDLINE, Ovid MEDLINE and In-Process & Other Non-Indexed Citations, Ovid MEDLINE Epub Ahead of Print, Cochrane Central Register of Controlled Trials (CENTRAL) and PubMed. Studies regarding RAI-induced SPMs or a dose-response relationship between RAI therapy and SPMs were identified, 10 of which were eligible for the analysis. We evaluated risk of bias in each study and judged quality of evidence (QOE) across all studies using the Grading of Recommendations, Assessment, Development and Evaluations approach.

RESULTS

For the outcome "SPM", the relative effect (relative risk, hazard ratio, or odds ratio) of RAI vs. no RAI ranged from 1.14 to 1.84 across studies, but most results were not statistically significant. For the outcome "SHM", reported relative effects ranged from 1.30 to 2.50, with 2/3 of the studies presenting statistically significant results. In 7/8 of the studies, increased risk for SPM was shown with increasing cumulative RAI activity. QOE was "very low" regarding SPM after RAI and regarding a dose-response relationship, and "low" for SHM after RAI.

CONCLUSION

Based on low quality evidence, an excess risk for the development of SPM cannot be excluded but is expected to be small.

Radioactive Iodine Treatment for Thyroid Cancer Patients Increases the Risk of Long-Term Gastrointestinal Disorders: A Nationwide Population-Based Cohort Analysis

Simple Summary

The standard treatment for well-differentiated thyroid cancer is thyroidectomy followed by radioactive iodine (RAI) treatment or active surveillance. Despite adequate documentation of acute gastrointestinal adverse effects after RAI treatment, whether the gastrointestinal exposure causes long-term comorbidity or not remained unclear. We conducted a nationwide, population-based retrospective cohort study using the data from the Taiwan National Health Insurance Research Database (NHIRD) to clarify the association between long-term gastrointestinal disorders (including ulcers, atrophic gastritis, and secondary stomach malignancy) and RAI treatment in thyroid cancer patients. We found that patients with RAI treatment were at a significantly higher risk of developing gastric and duodenal ulcers than those without. In addition, a higher cumulative dose is associated with higher risk. Therefore, follow-ups at gastrointestinal clinics might be of great importance for patients presenting with chronic gastrointestinal discomforts, after receiving a single RAI dose of more than 1.11 GBq, and undergoing repeated treatment due to recurrent or residual thyroid cancer.

Abstract

(1) Background: The study aimed to investigate the association between radioactive iodine (RAI) treatment and long-term gastrointestinal disorders including ulcers, atrophic gastritis, and secondary malignant neoplasm of the stomach in patients with thyroid cancer. (2) Methods: The data of the study were extracted from the National Health Insurance Database (NHIRD) of Taiwan between 2000 to 2015. Patients of ages older than 20 with thyroid cancer after thyroidectomy were included and divided into groups with RAI (study cohort) and without RAI (comparison cohort). Multivariate Cox proportional hazards regression analysis and the Kaplan–Meier method were used for statistical analysis. (3) Results: A total of 7250 (with RAI: 5800, without RAI: 1450) patients were included. The Kaplan-Meier analysis revealed a significantly higher cumulative risk for overall gastrointestinal disorders in the group with RAI (log-rank p = 0.034). The risk for gastrointestinal disorders was higher when receiving a cumulative RAI dose higher than 1.11 GBq in the Cox regression analysis. In the subgroup analysis, the risks of gastric and duodenal ulcers are significantly higher in the group with RAI treatment. (4) Conclusions: This study revealed that RAI was associated with an increased risk for long-term gastrointestinal disorders, specifically gastric and duodenal ulcers, in thyroid cancer, especially when the cumulative dose exceeds 1.11 GBq.

Cu(II) Coordination Complex: Anti-Thyroid Carcinoma Activity by Initiating Reactive Oxygen Species Accumulation and Inducing Cell Apoptosis

A mixed-donor ligand that shows pyrazole and carboxylic groups and a coordination complex that include Cu(II) has been created in the present study by mixing Hcppp with Cu(NO3)2 ·3H2O in water and DMF mixed solvent. The chemical formula of the compound is [Cu2(cppp)2(Hcppp)2(H2O)2] ·2NO3 ·6H2O. Additionally, Complex 1’s inhibitory influence against the cell proliferation of K1 human thyroid carcinoma cells was explored via exploiting the Cell Counting Kit-8 analysis. Annexin V-FITC/PI double staining analysis was finished to evaluate Complex 1’s mechanism, which induced the death of K1thyroid carcinoma cells. Moreover, the reactive oxygen species (ROS) analysis was implemented to determine the accumulation of ROS in K1 thyroid carcinoma cells.

Radicular variant of dens in dente (RDinD) in a patient undergoing radioisotope therapy

Dense in dente is a developmental anomaly frequently encountered in permanent maxillary incisors, with a prevalence rate of 0.25–10%. Our review of the scientific literature on a radicular variant of dens in dente (RDinD) in permanent molar teeth identified only two reported cases with a confirmed diagnosis. Here, we report the third case of RDinD, in a 37-year-old woman presenting with nocturnal pain in the left maxillary second molar for 1 week. The patient had a medical history of surgery for papillary thyroid carcinoma followed by radioactive iodine therapy. We established a diagnosis of RDinD with an osteolytic lesion and transverse fracture line along the palatal root of the tooth by using cone beam computed tomography (CBCT). Extraction and periapical curettage of the lesion were performed, and the patient was followed up. In summary, we observed a rare clinical presentation of RDinD in the left maxillary second molar of a 37-year-old female patient.

Epitopes specificity of antibodies to thyroid peroxidase in patients with Graves’ disease, Hashimoto’s thyroiditis and overlap-syndrome

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Further research that may shed light on specificity of MAbs in various TAIDs is strongly needed.

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Heterogeneity of epitopes recognized by anti-TPO in patients with HT, GD and overlap-syndrome may help to clarify specificity of MAbs in various TAIDs.

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Various MAbs in HT, GD and overlap-syndrome is different and this might be influenced by concentration of TPO in blood serum.

Background

Antibodies against thyroid peroxidase (anti-TPO) serve as clinical markers of thyroid autoimmune diseases (TAIDs). By trying to elucidate the causes of heterogeneity in autoantibody levels among patients with different TAIDs it becomes possible to clarify the pathophysiology of GD and HT.

Objective

To investigate the heterogeneity of epitopes recognized by anti-TPO in patients with Hashimoto’s thyroiditis (HT), Graves’ disease (GD) and overlap-syndrome.

Methods

We carried out a cross-sectional study on 398 patients with GD, HT and overlap syndrome and analyzed the specificity of epitopes and binding constants of TPO with monoclonal antibodies (MAbs). Ten MAbs to TPO were used, of which five were reactive with native TPO and the rest were reactive with denaturated TPO.

Results

The autoantibodies in blood serum of HT patients inhibited the binding of MAb63 more significantly than those in serum of GD patients: 59.62 % versus 54.02 %, respectively (p = 0.001). The anti-TPOs in serum of GD patients inhibited the binding of MAb77 more significantly than those in serum of HT patients: 54.36 % versus 51.13 %, respectively (p = 0.047). The binding of MAb45 was more inhibited in serum of patients with anti-TPO concentration over 1000 IU/ml (58.36 %). The blood serum of patients with overlap-syndrome showed less significant inhibition of MAb63 binding than that of patients with no overlap-syndrome: 52.47 % versus 58.81 %, respectively (p = 0.043).

Conclusion

Mapping the epitopes to TPO with the help of MAbs may improve the differential diagnosis between different thyroid autoimmunities.

HSA-MnO2-131I Combined Imaging and Treatment of Anaplastic Thyroid Carcinoma

Purpose Compelling evidence suggests that nanoparticles (NPs) play a crucial role in cancer therapy. NPs templated with human serum albumin (HSA) has good retention in tumors. Manganese dioxide (MnO₂) has been used to enhance the effect of radiotherapy. In this study, synthesized NPs using HSA-MnO₂ labeled ¹³¹I to perform both imaging and therapy for anaplastic thyroid carcinoma (ATC). Method HSA-MnO₂ was synthesized via HSA using a simple biomineralization method, and then labeled with Na¹³¹I by the chloramine T method. The cytotoxicity and biosafety of HSA-MnO₂ were evaluated by the MTT test. The proliferation-inhibiting effect of HSA-MnO₂-¹³¹I was evaluated in papillary thyroid cancer cell lines (K1, BCPAP, and KTC) and anaplastic thyroid carcinoma cell lines (Cal62, THJ16T, and ARO). For further translational application in medicine, we established a model of transplantable subcutaneously tumors in BALB\c-nu mice to assess the anti-tumor effect of HSA-MnO₂-¹³¹I. The imaging effects of NPs were evaluated by MRI and SPECT/CT. Results The MTT test proved that the HSA-MnO₂ had low toxicity. HSA-MnO₂-¹³¹I significantly inhibited the proliferation of PTC and ATC cell lines. In addition, the results unveiled that HSA-MnO₂-¹³¹I exhibited dual-modality MR/SPECT imaging for thyroid cancer visualization. In particular, HSA-MnO₂-¹³¹I had an enhanced T1 signal in MR. Using SPECT/CT, we observed that HSA-MnO₂-¹³¹I had good retention in tumor tissue, which was helpful for the diagnosis and treatment of tumor. In vivo assays indicated that the NPs led to a reduction in radioresistance in the tumor hypoxic microenvironment. Conclusion The nanomaterial had a simple synthesis method, good water solubility and biosafety, and good retention in tumor tissue. Hence, it could be used for SPECT/CT and MR dual mode imaging and therapy with radioiodine of tumor cells. The experimental results provided a feasible solution for combining radiotherapy and dual-model imaging by NPs for cancer diagnosis and 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.

Bethanechol used to prevent salivary gland dysfunction in patients submitted to radioactive iodine therapy: A double blind, placebo-controlled, randomized study

Symptoms related to salivary gland damage are one of the most frustrating complications after radioactive iodine (¹³¹I) therapy. To the best of our knowledge, this is the first study that aimed to evaluate the prophylactic effect of Bethanechol on the radioiodine content of salivary gland. Fifty patients who were referred to ¹³¹I therapy were randomized into Bethanechol and placebo groups. Patients received Bethanechol or Placebo (25 mg, 2 times daily), starting 2 h after ¹³¹I therapy to 1-month.  Both groups were compared at baseline, 10, 30 and 90 days after ¹³¹I therapy based on the following: symptoms related to salivary gland damage; unstimulated whole saliva (UWS) and quality of life using University of Washington Quality of Life 4 questionnaire. Bethanechol group presented significantly lower complaints of dry mouth on 10 (p = 0.047) and 30 (p = 0.003) days compared with placebo. Salivary gland pain and swelling were more frequent among placebo patients at 10 days (p = 0.047). Comparison of the two groups by UWS, no statistical difference was found. Placebo group presented worse score related to activity (p = 0.034), saliva (p = 0.05) and humor (p = 0.05) at 10 days; palate (p = 0.05) and saliva (p = 0.05) at 1 month. Interestingly, Bethanechol patients who received ¹³¹I dose > 125mCi, showed better xerostomia indices when compared to the Placebo with same dose. Bethanechol during ¹³¹I therapy was found to be effective in decreasing the acute salivary gland damage with impact on patients' quality of life.

Biodistribution and image characteristics of 124 I-positron emission tomography in dogs with neuroendocrine neoplasia

Radioactive iodine is frequently used for staging of human thyroid carcinomas. Iodine-124 scans performed using position emission tomography (PET) allow for more precise dosimetry of therapeutic radioiodine. The distribution of I-124 has not previously been described in veterinary medicine. The purpose of this prospective, exporatory, descriptive study is to evaluate the whole-body distribution of I-124 in dogs with suspected thyroid carcinoma. Ten dogs with either a cytologic diagnosis of a neuroendocrine neoplasm or biochemical hyperthyroidism were enrolled in a prospective clinical study. Whole-body I-124 PET/CT scans were performed and were evaluated for physiologic and pathologic uptake of I-124. The maximum and mean standardized uptake values (SUVmean) were recorded for several normal and abnormal tissues. Varying degrees of uptake were found in thyroid tumors (SUVmean = 66.37), ectopic thyroid masses (21.44), presumed metastatic lesions in lymph nodes (32.14), and the pulmonary parenchyma (4.50). In most dogs, physiologic uptake above background, measured in maximum SUV, was identified in parotid and mandibular salivary glands (14.00 and 1.57) the urinary tract (1.83), the gastrointestinal tract (19.90 stomach, 6.15 colon), the liver (1.41), and the heart (1.88). Occasionally, uptake was identified in the nasolacrimal duct (3.42), salivary duct (2.73), gallbladder (2.68), and anal gland (2.22). Physiologic uptake was also identified in normal thyroid glands and ectopic thyroid tissue. This study provides a baseline of pathologic and physiologic uptake of I-124 in dogs with thyroid carcinoma, to guide interpretation of future studies.

Side effects of theragnostic agents currently employed in clinical practice

Nuclear medicine plays an increasingly important role in several neoplasms management through a theragnostic approach by which targeted molecular imaging and radiotherapy are obtained with the use of radionuclide pairs with similar characteristics. In some cases, nuclear theragnostic use a pair of agents with identical chemical and biological characteristics while in others are employed theragnostic molecules which are not chemically or biologically identical but show similar biodistribution (so-called "twins in spirit" radiopharmaceuticals). This strategy was developed for the first time over 75 years ago, when iodine-131 was used for diagnostic imaging, confirmation of target expression and radionuclide therapy of thyroid cancer. Other theragnostic approaches were subsequently introduced with significant clinical results and some of them are currently considered standard treatment for different cancers. However, as any other therapy, also nuclear theragnostic treatment carries the potential risk of early deterministic and late stochastic off-target adverse effects, generally minimal and easily managed. This article reviews the reported side effects and risks of the main radiopharmaceuticals used for nuclear theragnostic in oncology for the treatment of thyroid cancer, neuroendocrine neoplasms, adrenergic tumors, metastatic prostate cancer, and liver tumors. Selecting appropriate patients using a multidisciplinary approach, meticulous pretreatment planning and knowledge of methods permit to decrease the incidence of these potential side effects.

Ameliorating effects of N-acetyl cysteine against early liver damage of radioiodine in rats

OBJECTIVE

The present study was aimed to explore the potential ameliorating effects of N-acetyl cysteine (NAC) against radioiodine (RAI)-induced early liver damage.

METHODS

Thirty Wistar Albino male rats were arbitrarily allocated into three groups each containing 10 rats: the control group (group 1); the RAI group (group 2), oral 111 MBq/kg radioiodine was administered to rats; the RAI + NAC group (group 3), 150 mg/kg/day intraperitoneal NAC treatment was initiated 3 days prior to the RAI administration and continued for 10 days. Liver samples were obtained 24 h after the last dose of NAC therapy for biochemical and histopathologic evaluation.

RESULTS

In the RAI + NAC group, the histopathologic damage was found significantly less than in the RAI group for whole parameters except inflammatory cell infiltration (P < 0.05). Unlike the RAI group which had marked histopathologic damage, the RAI + NAC group had only mild histologic activity index scores with no granuloma formation observed. Oxidative stress parameters were demonstrated that the NAC treatment significantly decreased the tissue malondialdehyde (MDA) and catalase levels and increased the total sulfhydryl (total sulfhydryl) levels when compared to the RAI group (P < 0.01).

CONCLUSION

The outcomes of the study exhibited that the NAC treatment improved RAI-induced early liver damage. This improving effect considered to be caused by its antioxidant, anti-inflammatory, and likely vasodilator properties of NAC. Having advantages such as inexpensive, easy access, and tolerability, the NAC can be used as a radioprotective agent, especially in patients with liver diseases and requiring RAI treatment.

Radioactive Iodine Treatment and the Risk of Long-Term Cardiovascular Morbidity and Mortality in Thyroid Cancer Patients: A Nationwide Cohort Study

(1) Background: This study aimed to investigate the association between radioactive iodine (RAI) and long-term cardiovascular disease (CVD) morbidity/mortality in thyroid cancer. (2) Methods: The study was conducted using data from the Taiwan National Health Insurance Database during 2000–2015. Thyroid cancer patients aged ≥20 years were categorized into RAI (thyroidectomy with RAI) and non-RAI (thyroidectomy only) groups. The Cox proportional hazard regression model and Kaplan–Meier method were used for analysis. (3) Results: A total of 13,310 patients were included. Kaplan–Meier analysis demonstrated that the two groups had similar cumulative risks of CVD (log-rank p = 0.72) and CVD-specific mortality (log-rank p = 0.62). On Cox regression analysis of different RAI doses, the risk of CVD was higher in the cumulative dosage >3.7 GBq (hazard ratio = 1.69, 95% confidence interval = 1.24–2.40, p < 0.001). (4) Conclusions: RAI was not associated with an increased risk of CVD in thyroid cancer. However, CVD surveillance is indicated in the patients receiving the cumulative RAI dosage above 3.7 GBq.

Silicon-photomultiplier-based PET/CT reduces the minimum detectable activity of iodine-124

The radioiodine isotope pair 124I/131I is used in a theranostic approach for patient-specific treatment of differentiated thyroid cancer. Lesion detectability is notably higher for 124I PET (positron emission tomography) than for 131I gamma camera imaging but can be limited for small and low uptake lesions. The recently introduced silicon-photomultiplier-based (SiPM-based) PET/CT (computed tomography) systems outperform previous-generation systems in detector sensitivity, coincidence time resolution, and spatial resolution. Hence, SiPM-based PET/CT shows an improved detectability, particularly for small lesions. In this study, we compare the size-dependant minimum detectable 124I activity (MDA) between the SiPM-based Biograph Vision and the previous-generation Biograph mCT PET/CT systems and we attempt to predict the response to 131I radioiodine therapy of lesions additionally identified on the SiPM-based system. A tumour phantom mimicking challenging conditions (derived from published patient data) was used; i.e., 6 small spheres (diameter of 3.7-9.7 mm), 9 low activity concentrations (0.25-25 kBq/mL), and a very low signal-to-background ratio (20:1). List-mode emission data (single-bed position) were divided into frames of 4, 8, 16, and 30 min. Images were reconstructed with ordinary Poisson ordered-subsets expectation maximization (OSEM), additional time-of-flight (OSEM-TOF) or TOF and point spread function modelling (OSEM-TOF+PSF). The signal-to-noise ratio and the MDA were determined. Absorbed dose estimations were performed to assess possible treatment response to high-activity 131I radioiodine therapy. The signal-to-noise ratio and the MDA were improved from the mCT to the Vision, from OSEM to OSEM-TOF and from OSEM-TOF to OSEM-TOF+PSF reconstructed images, and from shorter to longer emission times. The overall mean MDA ratio of the Vision to the mCT was 0.52 ± 0.18. The absorbed dose estimations indicate that lesions ≥ 6.5 mm with expected response to radioiodine therapy would be detectable on both systems at 4-min emission time. Additional smaller lesions of therapeutic relevance could be detected when using a SiPM-based PET system at clinically reasonable emission times. This study demonstrates that additional lesions with predicted response to 131I radioiodine therapy can be detected. Further clinical evaluation is warranted to evaluate if negative 124I PET scans on a SiPM-based system can be sufficient to preclude patients from blind radioiodine therapy.

Progressive changes in the major salivary gland after radioiodine therapy for differentiated thyroid cancer: a single-center retrospective ultrasound cohort study

This study aimed to determine the prevalence of radioiodine-induced salivary gland damage by evaluating progressive changes in salivary glands using ultrasound. Four hundred forty-six patients with differentiated thyroid carcinoma who underwent total or near-total thyroidectomy and postoperative radioiodine therapy were retrospectively reviewed. From the first to the fifth follow-up visits, the positive rate of major salivary gland changes on ultrasound gradually increased from 2.0% to 33.0% (P<0.001) and possibly stabilized at the fifth visit (approximately 36 months). The first positive result was detected at an average of 20.78±8.72 months. Only 21 of the 161 positive cases eventually achieved negative ultrasound results (Fisher's test, P<0.001), and the 21 cases simply showed a coarse echotexure. In conclusion, ultrasound changes appeared late, and most of these changes were not reversed.

Radioactive polymeric nanoparticles for biomedical application

Nowadays, emerging radiolabeled nanosystems are revolutionizing medicine in terms of diagnostics, treatment, and theranostics. These radionuclides include polymeric nanoparticles (NPs), liposomal carriers, dendrimers, magnetic iron oxide NPs, silica NPs, carbon nanotubes, and inorganic metal-based nanoformulations. Between these nano-platforms, polymeric NPs have gained attention in the biomedical field due to their excellent properties, such as their surface to mass ratio, quantum properties, biodegradability, low toxicity, and ability to absorb and carry other molecules. In addition, NPs are capable of carrying high payloads of radionuclides which can be used for diagnostic, treatment, and theranostics depending on the radioactive material linked. The radiolabeling process of nanoparticles can be performed by direct or indirect labeling process. In both cases, the most appropriate must be selected in order to keep the targeting properties as preserved as possible. In addition, radionuclide therapy has the advantage of delivering a highly concentrated absorbed dose to the targeted tissue while sparing the surrounding healthy tissues. Said another way, radioactive polymeric NPs represent a promising prospect in the treatment and diagnostics of cardiovascular diseases such as cardiac ischemia, infectious diseases such as tuberculosis, and other type of cancer cells or tumors.

The effect of I-131 therapy on pregnancy outcomes after thyroidectomy in patients with differentiated thyroid carcinoma: a meta-analysis

PURPOSE

Studies on the effects of I-131 therapy on pregnancy outcomes after differentiated thyroid carcinoma (DTC) surgery showed inconsistent findings. The purpose of the study was to investigate the association between I-131 therapy and pregnancy outcomes in female DTC patients.

METHODS

PubMed, Embase, Cochrane Library, CNKI, and VIP were searched until November, 2020. Keywords included differentiated thyroid cancer, thyroid carcinoma, thyroid neoplasm, radioiodine, I-131, ¹³¹I, pregnancy outcomes, reproduction, fertility, abortion, preterm birth, and congenital malformation. Studies that provided the pregnancy outcomes in DTC patients who received I-131 therapy and those who did not receive I-131 therapy were included. Meta-analysis was performed in Stata/SE 12. A random or fixed effects model was adopted according to the result of heterogeneity test.

RESULTS

Seven observational studies were eligible, involving 125,591 participants and 13,811 pregnancies. It showed that postoperative I-131 therapy for DTC had no significant effect on spontaneous abortion (OR = 1.05, P = 0.701), induced abortion (OR = 1.06, P = 0.859), abortion (OR = 1.07, P = 0.098), premature birth (OR = 1.02, P = 0.756), stillbirth (OR = 1.58, P = 0.364), and congenital malformation(OR = 1.00, P = 0.986). Cumulative RAI dose >3.7 GBq or <3.7 GBq had no significant effect on abortion (OR = 0.94, P = 0.252) and congenital malformation (OR = 1.05, P = 0.752).The group in which interval time between last I-131 therapy and pregnancy >1 year had significant lower risk of abortion than with interval <1 year (OR = 0.60, P = 0.000).

CONCLUSIONS

Pregnancy is not recommended for DTC patients within 1 year after I-131 therapy.

Less extensive surgery for low-risk papillary thyroid cancers post 2015 American Thyroid Association guidelines in an Australian tertiary centre

INTRODUCTION

The 2015 American Thyroid Association guidelines (ATA15) consider hemithyroidectomy (HT) a viable treatment option for low-risk papillary thyroid cancers (PTCs) between 1 and 4 cm. We aimed to examine the impact of ATA15 in a high-volume Australian endocrine surgery unit.

METHODS

A retrospective study of all patients undergoing thyroidectomy from January 2010 to December 2019.

INCLUSION CRITERIA

PTC histopathology, Bethesda V-VI, size 1-4 cm, and absence of clinical evidence of lymph node or distant metastases pre-operatively. Primary outcome was rate of HT before and after ATA15.

RESULTS

Of 5408 thyroidectomy patients, 339 (6.3%) met the inclusion criteria - 186 (54.9%) pre-ATA15 (2010-2015) and 153 (45.1%) post-ATA15 (2016-2019). The patient groups were similar; there were no significant differences between groups in age, sex, tumour size, proportion with Bethesda VI cytology, compressive symptoms, or thyrotoxicosis. Post-ATA15, there was a significant increase in HT rate from 5.4% to 19.6% (P = 0.0001). However, there was no corresponding increase in completion thyroidectomy (CT) rate (50.0% versus 27.6%, P = 0.2). The proportion managed with prophylactic central neck dissection (pCND) fell from 80.5% to 10.8% (P < 0.0001). Pre-ATA15, the only factor significantly associated with HT was Bethesda V. In contrast, post-ATA15, HT was more likely in patients with younger age, smaller tumours, and Bethesda V.

CONCLUSION

After the release of 2015 ATA guidelines, we observed a significant increase in HT rate and a significant decrease in pCND rate for low-risk PTCs in our specialised thyroid cancer unit. This reflects a growing clinician uptake of a more conservative approach as recommended by ATA15.

Effect of ¹³¹I Therapy on Complete Blood Count in Patients with Differentiated Thyroid Cancer

Background

The aim of this study was to investigate the effects of ¹³¹I therapy on complete blood count (CBC) in patients with differentiated thyroid cancer (DTC).

Materia/Methods

We analyzed CBC in 542 patients with DTC who were grouped according to treatment cycles and cumulative dose and then subdivided by sex and age. The effects of ¹³¹I therapy among the different groups and subgroups were analyzed.

Results

After sorting patients by treatment cycles and doses, ¹³¹I therapy was found to have different effects on CBC depending on patient sex and age. The effect on white blood cell (WBC) counts persisted longer in women, while increases in hemoglobin (Hb) were more significant in men. The influence on red blood cell (RBC) counts was short-lived in patients aged 45 to 54 years. Monocyte counts were significantly decreased only in patients aged 55 years and older who had undergone 3 or 4 treatment cycles. In men, CBC was more affected by cumulative dose. ¹³¹I therapy only influenced platelet and monocyte counts in patients aged 55 years or older. Hb was significantly decreased and increased in the high- and low-dose groups, respectively. No significant complications were observed during follow-up.

Conclusions

¹³¹I therapy had a greater impact on WBC counts in women, while changes in RBC counts and Hb were more obvious in men. During ¹³¹I therapy, clinicians should pay attention to different CBC indicators based on a patient’s sex and age, but risks associated with an altered CBC are unlikely to outweigh the benefits of ¹³¹I. The results of the present study may help alleviate the concerns of a large proportion of patients with DTC and their families about the effects of ¹³¹I therapy on CBC.

Influence of Socioeconomic Status on Incident Medical Conditions in Two-Year Survivors of Adolescent or Young Adult Differentiated Thyroid Cancer

Purpose: We sought to enumerate secondary medical conditions from hospitalization records in adolescent and young adult (AYA) differentiated thyroid cancer (DTC) survivors and identify characteristics of patients with increased likelihood of subsequent medical diagnoses. Methods: Using data from the California Cancer Registry and statewide hospitalization data, we examined incident oncologic, endocrine, pulmonary, hematologic, and cardiovascular diagnoses in 12,312 AYA (aged 15-39) patients diagnosed with DTC in 1996-2012 and surviving >2 years after diagnosis with follow-up through 2014. We calculated the cumulative incidence of each condition accounting for the competing risk of death and used multivariable Cox proportional hazards regression to evaluate sociodemographic and clinical characteristics associated with each incident condition. Results: The 10-year cumulative incidences of multiple medical conditions were particularly high in blacks and Hispanics. Asian/Pacific Islander survivors were most likely to develop subsequent cancers. Men had higher rates of cardiovascular and diabetes diagnoses than women, but lower rates of asthma and cytopenias. Low socioeconomic status and/or public or no insurance were associated with a higher risk of several diagnoses. More extensive disease stage and thyroid surgery increased the risk of calcium and phosphorus metabolism disorders. Neck reoperation associated with the risk of cytopenias, as well as subsequent endocrine, cardiovascular, and respiratory diagnoses. Conclusions: The incidence of medical conditions after thyroid cancer diagnosis and treatment differ among racial/ethnic groups and sexes. Those residing in lower socioeconomic neighborhoods, those with public or no insurance, and those who require further neck surgery have substantially higher burdens of subsequent medical diagnoses.

The effects of radioiodine therapy on parathyroid function among patients with papillary thyroid cancer: a retrospective cohort study

PURPOSE

To explore the effects of initial radioiodine therapy on parathyroid function among postoperative papillary thyroid cancer (PTC) patients.

METHODS

Postoperative PTC patients who were admitted in our department from April 2018 to April 2019 were recruited. Patients were divided into two groups: Group A, who underwent surgery and initial radioiodine therapy in our hospital, and Group B, who did not receive radioiodine therapy after surgery. The levels of serum calcium, magnesium, phosphorus, parathyroid hormone (PTH), and 25 hydroxyvitamin D3 were collected. Data were analyzed by SPSS 25.0.

RESULTS

A total of 252 patients were included. Between the two groups, no significant difference of PTH in 6th, 9th, and 12th month was found during postoperative follow-up (p = 0.493, p = 0.202, p = 0.814). No significant difference of PTH was found after stratifying Group A according to ¹³¹I dosage (p = 0.751 for 6th month after operation, p = 0.130 for 9th month after operation, p = 0.683 for 12th month after operation), interval time between surgery and radioiodine therapy (p = 0.522 for 3rd day after ¹³¹I therapy, p = 0.184 for 9th month after operation, p = 0.311 for 12th month after operation), and ratio of parathyroid autotransplantation (p = 0.545 for 3rd day after ¹³¹I therapy, p = 0.485 for 6th month after operation, p = 0.201 for 9th month after operation, p = 0.146 for 12th month after operation).

CONCLUSIONS

Initial radioiodine therapy following PTC surgery had no significant adverse effect on parathyroid function in the short term. However, physicians should inform patients of possible risks of abnormal parathyroid function prior to RAI therapy, and parathyroid function was periodically reviewed after RAI therapy.

Incidence and risk factors for radioactive iodine-induced sialadenitis

BACKGROUND

Radioactive iodine (¹³¹I) is one of the treatments of hyperthyroidism and differentiated thyroid carcinoma (DTC). Swelling of salivary glands are one of the possible side effects of this treatment, known as radioactive iodine-induced sialadenitis (RAIS). The prevalence of RAIS varies widely and no specific risk ratio has been established.

OBJECTIVES

To determine the incidence of RAIS, analysing the epidemiological data and tumour- and treatment-related factors that may influence the development of the disease.

MATERIAL AND METHODS

197 patients who received radioiodine treatment between 2015 and 2017 were studied (76.6% women). The variables studied were age, gender, weight, height, and body mass index; presence of high blood pressure, dyslipidemia, diabetes, and thyroid diseases; cumulative radioiodine dose, presence of sialadenitis, affected salivary gland, and the time of onset.

RESULTS

14 patients developed sialadenitis (78.6% women), all with DTC. The incidence of sialadenitis was 3.4% overall and 6.3% among DTC patients. Furthermore, we found that higher cumulative radioiodine doses confer a greater risk of developing sialadenitis, with a hazard ratio of 1.009 (p = .001). No association was found between the epidemiologic data studied and sialadenitis.

CONCLUSIONS

In this series, a dose-dependent relationship was found between radioiodine treatment and sialadenitis.

Prophylactic prednisolone for the prevention of early and intermediate adverse effects of radioactive iodine therapy in patients with thyroid cancer: study protocol for a single-centre, phase II/III, randomized, double-blinded, placebo-controlled clinical trial

Background

Radioactive iodine (RAI) therapy is the standard adjuvant treatment for differentiated thyroid cancer (i.e. papillary and follicular). RAI is associated with troublesome early, intermediate and late adverse effects. Although glucocorticoids are used for the management of these adverse effects, there is little evidence regarding the effectiveness of prophylactic glucocorticoids to prevent these complications. This trial will evaluate the efficacy of a short course of prophylactic glucocorticoids in the prevention of adverse effects of RAI treatment in patients with differentiated thyroid cancer.

Methods

A phase II/III, single-centre, randomized, double-blinded, placebo-controlled, parallel-arm clinical trial will be conducted. Patients with differentiated thyroid cancer who are referred to RAI therapy at the National Cancer Institute, Sri Lanka, will be randomized into two arms consisting of 200 patients each. The experimental group will receive prophylactic oral prednisolone 0.5 mg/kg and omeprazole 20 mg single dose 6 h before RAI therapy followed by oral prednisolone 0.5 mg/kg and omeprazole 20 mg daily for 3 days. The control group will receive oral placebo and omeprazole 20 mg single dose 6 h before RAI therapy followed by oral placebo and omeprazole 20 mg daily for 3 days. Clinically significant adverse effects assessed as related to RAI as well as prednisolone therapy and the quality of life parameters will be compared between the two groups.

Discussion

If proven beneficial, this intervention can be incorporated into the standard practice to reduce early and intermediate adverse effects of RAI for thyroid cancer with a potential improvement of quality of life.

Trial registration

Sri Lanka Clinical Trials Registry SLCTR/2020/009. Registered prospectively on 23 February 2020. Items of the WHO Trial Registration Data Set are provided in the supplementary file.

Long-Term Effects of Radioiodine Treatment on Female Fertility in Survivors of Childhood Differentiated Thyroid Carcinoma

Background: Differentiated thyroid carcinoma (DTC) during childhood is a rare disease. Its excellent survival rate requires a focus on possible long-term adverse effects. This study aimed to evaluate fertility in female survivors of childhood DTC by assessing various reproductive characteristics combined with anti-Müllerian hormone (AMH) levels (a marker of ovarian reserve). Methods: Female survivors of childhood DTC, diagnosed at ≤18 years of age between 1970 and 2013, were included. Survivors were excluded when follow-up time was less than five years or if they developed other malignancies before or after diagnosis of DTC. Survivors filled out a questionnaire regarding reproductive characteristics (e.g., age at menarche and menopause, pregnancies, pregnancy outcomes, need for assisted reproductive therapy). Survivors aged <18 years during evaluation received an altered questionnaire without questions regarding pregnancy and pregnancy outcomes. These data were combined with information from medical records. AMH levels were measured in serum samples and were compared with AMH levels from 420 women not treated for cancer. Results: Fifty-six survivors with a median age of 31.0 (interquartile range, IQR, 25.1-39.6) years were evaluated after a median follow-up of 15.4 (IQR 8.3-24.7) years. The median cumulative dose of ¹³¹I administered was 7.4 (IQR 3.7-13.0) GBq/200.0 (IQR 100.0-350.0) mCi. Twenty-five of the 55 survivors aged 18 years or older during evaluation reported 64 pregnancies, 45 of which resulted in live birth. Of these 55, 10.9% visited a fertility clinic. None of the survivors reported premature menopause. Age at AMH evaluation did not differ between DTC survivors and the comparison group (p = 0.268). Median AMH levels did not differ between DTC survivors and the comparison group [2.0 (IQR 1.0-3.7) μg/L vs. 1.6 (IQR 0.6-3.1) μg/L, respectively, p = 0.244]. The cumulative dose of ¹³¹I was not associated with AMH levels in DTC survivors (r_s = 0.210, p = 0.130). Conclusions: Female survivors of DTC who received ¹³¹I treatment during childhood do not appear to have major abnormalities in reproductive characteristics nor in predictors of ovarian failure.

Assessment and Care of Oral Lesions for Patients Who Undergo Radioiodine Treatment for Thyroid Cancer

Patients with differentiated thyroid cancer who undergo radioiodine treatment often present oral complications with a significant impact on their oral cavity function. Any potential sources of systemic infections like periodontal disease, unfitted dentures, orthodontic appliances, deficient/rough fillings, or traumatic dentition must be treated by the dental practitioner, because they represent the main source of spread and dissemination. Any systemic complication of a dental foci may result from improper dental preparation of the patient before radioiodine therapy and inadequate post-radioiodine therapy oral care. Therefore, all patients proceeding into radioiodine treatment should be addressed by the oncological team to undergo thorough dental check-up and receive appropriate treatment in due time.

Salivary side effects after radioiodine treatment for differentiated papillary thyroid carcinoma: Long-term study

BACKGROUND

Although many studies focus on short-term side effects of radioiodine therapy, almost none studied long-term side effects. We assessed radioiodine long-term salivary side effects after radioiodine treatment for differentiated papillary thyroid carcinoma and compared it to short-term morbidity within the same population.

METHODS

A standardized self-administrated questionnaire was submitted in 2019 by patients treated with radioiodine between January 2011 and December 2012. These patients had already answered the same questionnaire 6 years before.

RESULTS

Our study showed a significant reduction for salivary side effects: discomfort in submandibular or parotid area, swelling, pain, a bad or salty taste in the mouth, allowing to get back to a "normal" diet.

CONCLUSIONS

Our study suggests that a significant rate of patients will recover from I¹³¹ therapy salivary side effects. As almost 30% of these remissions happened during our late stage follow-up, we highlight the necessity of a long-term follow-up in these patients.

Contemporary considerations in adjuvant radioiodine treatment of adults with differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy with a growing incidence worldwide. The initial conventional management is surgery, followed by consideration of ¹³¹ I treatment that includes three options. These are termed remnant ablation (targeting benign thyroid remnant), adjuvant (targeting presumed microscopic DTC) and known disease (targeting macroscopic DTC) treatments. Some experts mostly rely on clinicopathologic assessment for recurrence risk to select patients for the ¹³¹ I treatment. Others, in addition, apply radioiodine imaging to guide their treatment planning, termed theranostics (aka theragnostics or radiotheragnostics). In patients with low-risk DTC, remnant ablation rather than adjuvant treatment is generally recommended and, in this setting, the ATA recommends a low ¹³¹ I activity. ¹³¹ I adjuvant treatment is universally recommended in patients with high-risk DTC (a primary tumor of any size with gross extrathyroidal extension) and is generally recommended in intermediate-risk DTC (primary tumor >4 cm in diameter, locoregional metastases, microscopic extrathyroidal extension, aggressive histology or vascular invasion). The optimal amount of ¹³¹ I activity for adjuvant treatment is controversial, but experts reached a consensus that the ¹³¹ I activity should be greater than that for remnant ablation. The main obstacles to establishing timely evidence through randomized clinical trials for ¹³¹ I therapy include years-to-decades delay in recurrence and low disease-specific mortality. This mini-review is intended to update oncologists on the most recent clinical, pathologic, laboratory and imaging variables, as well as on the current ¹³¹ I therapy-related definitions and management paradigms, which should optimally equip them for individualized patient guidance and treatment.

Preclinical Evaluation of Radiation-Induced Toxicity in Targeted Alpha Therapy Using [211At] NaAt in Mice: A Revisit

We recently reported the dose-dependent therapeutic effect of ²¹¹At-NaAt in differentiated thyroid cancer xenograft models. In the present study, we evaluated the radiation-induced toxicity of ²¹¹At-NaAt using detailed hematological, biochemical, and histological analyses. Biodistribution of ²¹¹At-NaAt was measured in normal ICR mice (n = 12), absorbed doses in the major organs were calculated. Groups of ICR mice (n = 60) were injected with 0.1 MBq or 1 MBq of ²¹¹At-NaAt, using saline as the control group (n = 30). Body weight and food intake were followed up for 60 days. Blood cell counts and serum level of biochemical parameters were measured 3, 7, 15, 29, 60 days after injection. Histological analyses of the major organs with hematoxylin and eosin staining were performed. Biodistribution study revealed a high-absorbed dose in the thyroid gland, stomach, bladder, heart, lungs, spleen, kidneys, and testis. The 0.1 MBq group showed no abnormalities. The 1 MBq group showed decreased body weight and food intake. Histological analysis showed atrophy and fibrosis in the thyroid gland, a transient hypospermatogenesis in the testis on day 29 was found in one mouse. Hematological toxicity was mild and transient. The total cholesterol, albumin, and total protein increased with no signs of recovery, which was considered to be caused by hypothyroidism. High-dose administration of ²¹¹At-NaAt showed transient toxicity in the white blood cells and testis without severe hematological or renal toxicity, suggesting its tolerable safety as targeted alpha-therapy for differentiated thyroid cancer in the 1 MBq group.