Radioactive iodine and the salivary glands

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.

Salivary iodine concentration in pregnant women and its association with iodine status and thyroid function

PURPOSE

There have been no reports on the application of salivary iodine concentration (SIC) in evaluating iodine nutrition in pregnant women. This study aimed to clarify the relationship between SIC and indicators of iodine nutritional status and thyroid function during pregnancy, to investigate whether salivary iodine can be applied to the evaluation of iodine nutritional status in pregnant women, and to provide a reference basis for establishing a normal range of salivary iodine values during pregnancy.

METHODS

Pregnant women were enrolled in the Department of Obstetrics, the people's hospital of Yuncheng Country, Shandong Province, from July 2021 to December 2022, using random cluster sampling. Saliva, urine, and blood samples were collected from pregnant women to assess iodine nutritional status, and venous blood was collected to determine thyroid function.

RESULTS

A total of 609 pregnant women were included in this study. The median spot urinary iodine concentration (SUIC) was 261 μg/L. The median SIC was 297 μg/L. SIC was positively correlated with SUIC (r = 0.46, P < 0.0001), 24-h UIC (r = 0.30, P < 0.0001), 24-h urinary iodine excretion (24-h UIE) (r = 0.41, P < 0.0001), and estimated iodine intake (EII) (r = 0.52, P < 0.0001). After adjusting for confounders, there was a weak correlation between SIC and serum total iodine and serum non-protein-bound iodine (P = 0.02, P = 0.04, respectively). Pregnant women with a SIC < 176 μg/L had a higher risk of insufficient iodine status (OR = 2.07, 95% CI 1.35-3.19) and thyroid dysfunction (OR = 2.71, 95% CI 1.18-6.21) compared to those with higher SIC. Those having SIC > 529 μg/L were more likely to have excessive iodine status (OR = 2.82, 95% CI 1.81-4.38) and thyroid dysfunction (OR = 3.04, 95% CI 1.36-6.78) than those with lower SIC values.

CONCLUSION

SIC is associated with urinary iodine concentration and thyroid function in pregnant women. SIC < 176 μg/L was associated with an increased risk for iodine deficiency and hypothyroxinemia, while SIC > 529 μg/L was related to excess and thyrotoxicosis. SIC can be used as a reference indicator for evaluating the iodine nutrition status of pregnant women, but it needs further investigation and verification.

TRIAL REGISTRATION

NCT04492657(Aug 9, 2022).

Salivary iodide status as a measure of whole body iodine homoeostasis?

Iodine is a trace element required to produce the thyroid hormones, which are critical for development, growth and metabolism. To ensure appropriate population iodine nutrition, convenient and accurate methods of monitoring are necessary. Current methods for determining iodine status either involve a significant participant burden or are subject to considerable intra-individual variation. The continuous secretion of iodide in saliva potentially permits its use as a convenient, non-invasive assessment of status in populations. To assess its likely effectiveness, we reviewed studies analysing the association between salivary iodide concentration (SIC) and dietary iodine intake, urinary iodide concentration (UIC) and/or 24-h urinary iodide excretion (UIE). Eight studies conducted in different countries met the inclusion criteria, including data for 921 subjects: 702 healthy participants and 219 with health conditions. SIC correlated positively with UIC and/or UIE in four studies, with the strength of relationship ranging from r = 0·19 to r = 0·90 depending on sampling protocol, age, and if salivary values were corrected for protein concentration. Additionally, SIC positively correlated with dietary intake, being strongest when saliva was collected after dinner. SIC varied with external factors, including thyroid function, use of some medications, smoking and overall health status. Evidence provided here supports the use of SIC as a viable, low-burden method for determining iodine status in populations. However, small sample sizes and high variability indicates the need for more extensive analyses across age groups, ethnicities, disease states and dietary groups to clarify the relative accuracy and reliability in each case and standardise procedure.

Ultrasound and Sialendoscopy Findings in Radioactive Iodine-Induced Sialadenitis: Comparative Analysis and Possible Impact on Management

BACKGROUND

To assess the correlation/association between ultrasound and sialendoscopy findings in radioactive iodine therapy-induced sialadenitis (RAIS).

METHODS

Patients presenting with RAIS were investigated with ultrasound and sialendoscopy. Four pathologic ultrasound parameters and seven pathologic sialendoscopy parameters were retrospectively assessed. Correlations/associations between ultrasound and sialendoscopy findings and associations between the changes between the first and last ultrasound and sialendoscopy findings were assessed separately for the parotid (PG) and submandibular glands (SMG).

RESULTS

Sixty-seven patients were included. In the first examination, 107 glands were investigated (PGs 88.8%, SMGs 11.21%), and in the last examination, 64 glands were investigated (90.6% PGs, 9.4% SMGs). Highly significant positive associations were observed between the severity or category of ultrasound and sialendoscopy findings for first and last examinations for PGs (both p = 0.0001) and SMGs (p = 0.002; p = 0.037). Duct dilation had a significant negative association with the sialendoscopy findings for PGs in the first and last examinations (both p = 0.0001), but not for SMGs. Comparison of changes in the ultrasound and sialendoscopy findings between the first and last examinations showed a significant positive association for PGs (p = 0.0001) but not for SMGs.

CONCLUSIONS

Ultrasound and sialendoscopy findings for the parenchyma and duct system in RAIS showed significant associations/correlations and can be useful for effective management in RAIS.

The effect of radioiodine therapy on blood cell count in patients with differentiated thyroid cancer

PURPOSE

This study aimed to investigate the long-term effects of radioiodine treatment (RAI) on blood cell counts in patients with differentiated thyroid cancer (DTC) and to describe the characteristics of patients at high risk for blood cell count abnormalities.

METHODS

The study included patients with DTC who underwent RAI treatment between 2007 and 2017. Patients with regular complete blood counts for at least 5 years were included, while those with diseases or treatments that could influence blood count parameters were excluded. Blood cell count abnormalities were defined according to the Common Terminology Criteria for Adverse Events version 5.0, and factors influencing these abnormalities were examined.

RESULTS

A total of 225 patients were analyzed. The mean age at diagnosis was 45.8 ± 13.9 years, and 76.5% of patients were female. In the first year after RAI, leukocyte, neutrophil, and lymphocyte counts were significantly reduced compared with baseline values. The leukocyte and neutrophil counts returned to baseline values by the third year, while the decrease in lymphocytes continued until the fifth year. Blood cell count abnormalities developed in 16 patients (7.1%) within the first year after RAI. Risk factors for blood cell count abnormalities within the first year after RAI included male sex, older age, T4, N1, and M1 disease, as well as higher RAI doses. In logistic regression analysis, only RAI dose remained independently associated with blood cell count abnormalities.

CONCLUSION

These results suggest an association between RAI dose and blood cell count abnormalities, characterized by mild lymphopenia, and indicate that the risk of mild lymphopenia persists over time. Careful consideration should be given when planning high-dose RAI for patients at a high risk of blood cell count abnormalities, such as males with metastatic disease and of advanced age.

Genetic markers associated with adverse reactions of radioiodine therapy in thyroid cancer patients

OBJECTIVES

Radioactive iodine therapy is considered for patients with certain clinicopathological factors that predict a significant risk of recurrence, distant metastases of thyroid cancer or disease-specific mortality. The aim of the study was to investigate the association between polymorphisms of genes, products of which are involved in the processes of DNA damage response and autophagy, and the adverse reactions of radioiodine therapy in thyroid cancer patients.

METHODS

The study included 181 patients (37 men, 144 women; median age 56 [41; 66.3] years) with histologically confirmed thyroid cancer and a history of thyroidectomy who received radioiodine therapy. NFKB1, ATM, ATG16L2, ATG10, TGFB1, and TNF polymorphisms were determined by allele-specific realtime-PCR.

RESULTS

The frequency of adverse reactions was the following: gastrointestinal symptoms - 57.9 %, local symptoms - 65.8 %, cerebral symptoms - 46.8 %, fatigue - 54.4 %; signs of sialoadenitis six months after radioiodine therapy - 25.2 %. TT genotype carriers of ATG10 rs1864183 had higher frequency of gastrointestinal symptoms (vs. CC+CT), the CC genotype carriers of ATG10 rs10514231 had significantly more frequent cerebral symptoms (vs. CT+TT), as well as AA genotype carriers of TGFB1 rs1800469 (vs. AG+GG). CC genotype of ATG10 rs10514231 increased the incidence of radioiodine-induced fatigue, whereas GA genotype of the ATM rs11212570 had a protective role against fatigue. TGFB1 rs1800469 was associated with signs of sialoadenitis six months after radioiodine therapy.

CONCLUSIONS

Genetic factors may contribute to the occurrence of adverse reactions of radioiodine therapy in thyroid cancer patients.

The EANM guideline on radioiodine therapy of benign thyroid disease

This document provides the new EANM guideline on radioiodine therapy of benign thyroid disease. Its aim is to guide nuclear medicine physicians, endocrinologists, and practitioners in the selection of patients for radioiodine therapy. Its recommendations on patients' preparation, empiric and dosimetric therapeutic approaches, applied radioiodine activity, radiation protection requirements, and patients follow-up after administration of radioiodine therapy are extensively discussed.

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.

Genetic markers associated with adverse reactions of radioiodine therapy in thyroid cancer patients

OBJECTIVES

Radioactive iodine therapy is considered for patients with certain clinicopathological factors that predict a significant risk of recurrence, distant metastases of thyroid cancer or disease-specific mortality. The aim of the study was to investigate the association between polymorphisms of genes, products of which are involved in the processes of DNA damage response and autophagy, and the adverse reactions of radioiodine therapy in thyroid cancer patients.

METHODS

The study included 181 patients (37 men, 144 women; median age 56 [41; 66.3] years) with histologically confirmed thyroid cancer and a history of thyroidectomy who received radioiodine therapy. NFKB1, ATM, ATG16L2, ATG10, TGFB1, and TNF polymorphisms were determined by allele-specific realtime-PCR.

RESULTS

The frequency of adverse reactions was the following: gastrointestinal symptoms - 57.9 %, local symptoms - 65.8 %, cerebral symptoms - 46.8 %, fatigue - 54.4 %; signs of sialoadenitis six months after radioiodine therapy - 25.2 %. TT genotype carriers of ATG10 rs1864183 had higher frequency of gastrointestinal symptoms (vs. CC+CT), the CC genotype carriers of ATG10 rs10514231 had significantly more frequent cerebral symptoms (vs. CT+TT), as well as AA genotype carriers of TGFB1 rs1800469 (vs. AG+GG). CC genotype of ATG10 rs10514231 increased the incidence of radioiodine-induced fatigue, whereas GA genotype of the ATM rs11212570 had a protective role against fatigue. TGFB1 rs1800469 was associated with signs of sialoadenitis six months after radioiodine therapy.

CONCLUSIONS

Genetic factors may contribute to the occurrence of adverse reactions of radioiodine therapy in thyroid cancer patients.

Imaging of Major Salivary Gland Lesions and Disease

Infectious and inflammatory disorders are the commonest pathologies to affect the major salivary glands however frequently overlap in clinical presentation. Imaging plays an important role in diagnosis, usually initially performed by CT or ultrasound. MRI, with its superior soft-tissue characterization compared with CT, provides a better evaluation of tumors and tumor-like conditions. Imaging features may suggest that a mass is more likely to be benign versus malignant, however, biopsy is often needed to establish a definitive histopathologic diagnosis. Imaging plays a key role in the staging of neoplastic disease.

Selenium and thyroid diseases

Selenium, a non-metallic element, is a micronutrient essential for the biosynthesis of selenoproteins containing selenocysteine. In adults, the thyroid contains the highest amount of selenium per gram of tissue. Most known selenoproteins, such as glutathione peroxidase, are expressed in the thyroid and are involved in thyroid hormone metabolism, redox state regulation, and maintenance of cellular homeostasis. Some clinical studies have shown that lack of selenium will increase the prevalence of several kinds of thyroid diseases. Selenium treatment in patients with Graves' orbitopathy has been shown to delay disease progression and improve the quality of life. Selenium supplementation in Hashimoto's thyroiditis was associated with the decreased levels of anti-thyroid peroxidase antibody and improved thyroid ultrasound structure. In thyroid cancer, various selenium supplements have shown variable anticancer activity. However, published results remain the conflicting and more clinical evidence is still needed to determine the clinical significance of selenium. This article reviews the strong association between selenium and thyroid disease and provides new ideas for the clinical management of selenium in thyroid disease.

Ultrasonographic Features of Salivary Glands after Radioiodine Therapy in Patients with Thyroid Cancer

OBJECTIVE

Chronic sialadenitis is the most common complication of radioactive iodine (RAI) treatment. The aim of the study was to ascertain sonographic features of the major salivary glands in patients with papillary thyroid cancer (PTC) treated with RAI.

METHODS

The database of a tertiary medical center was retrospectively searched for consecutive patients who underwent total thyroidectomy for PTC in 2011-2020 with ultrasound follow-up after 1 year. Changes in ultrasound features of the major salivary glands were compared between patients treated or not treated with RAI postoperatively.

RESULTS

The cohort included 158 patients, of whom 109 (69%) were treated postoperatively with RAI (mean dose, 131 mCi) and 49 were not (control group). Sonographic changes were observed in the major salivary glands in 43% of the study group and 18% of the control group (p = 0.002), including coarse echotexture, decreased echogenicity, fibrosis, and atrophy. Higher RAI doses were significantly correlated with the prevalence and severity of glandular changes (p < 0.0001).

CONCLUSION

RAI treatment following thyroidectomy is associated with a dose-response effect and adverse changes in the major salivary glands and should be prescribed carefully.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:1271-1275, 2023.

Salivary Gland Toxicity of PSMA-Targeted Radioligand Therapy with 177Lu-PSMA and Combined 225Ac- and 177Lu-Labeled PSMA Ligands (TANDEM-PRLT) in Advanced Prostate Cancer: A Single-Center Systematic Investigation

Purpose: PSMA-targeted radioligand therapy (PRLT) is a promising treatment option for patients with metastatic castration-resistant prostate cancer (mCRPC). However, a high uptake of the radiopharmaceutical in the salivary glands (SG) can lead to xerostomia and becomes dose-limiting for 225Ac-PSMA-617. This study investigated the sialotoxicity of 177Lu-PSMA-I&T/-617 monotherapy and co-administered 225Ac-PSMA-617 and 177Lu-PSMA-617 (Tandem-PPRLT). Methods: Three patient cohorts, that had undergone 177Lu-PSMA-I&T/-617 monotherapy or Tandem-PRLT, were retrospectively analyzed. In a short-term cohort (91 patients), a xerostomia assessment (CTCAE v.5.0), a standardized questionnaire (sXI), salivary gland scintigraphy (SGS), and SG SUVmax and the metabolic volume (MV) on 68Ga-PSMA-11-PET/CT were obtained before and after two cycles of 177Lu-PSMA-I&T/-617. In a long-term cohort, 40 patients were similarly examined. In a Tandem cohort, the same protocol was applied to 18 patients after one cycle of Tandem-PRLT. Results: Grade 1 xerostomia in the short-term follow-up was observed in 22 (24.2%) patients with a worsening of sXI from 7 to 8 at (p < 0.05). In the long-term cohort, xerostomia grades 1 to 2 occurred in 16 (40%) patients. SGS showed no significant changes, but there was a decline of the MV of all SGs. After Tandem-PRLT, 12/18 (66.7%) patients reported xerostomia grades 1 to 2, and the sXI significantly worsened from 9.5 to 14.0 (p = 0.005), with a significant reduction in the excretion fraction (EF) and MV of all SGs. Conclusion: 177Lu-PSMA-I&T/-617 causes only minor SG toxicity, while one cycle of Tandem-PRLT results in a significant SG impairment. This standardized protocol may help to objectify and quantify SG dysfunction.

Personalized Dosimetry in the Context of Radioiodine Therapy for Differentiated Thyroid Cancer

The most frequent thyroid cancer is Differentiated Thyroid Cancer (DTC) representing more than 95% of cases. A suitable choice for the treatment of DTC is the systemic administration of 131-sodium or potassium iodide. It is an effective tool used for the irradiation of thyroid remnants, microscopic DTC, other nonresectable or incompletely resectable DTC, or all the cited purposes. Dosimetry represents a valid tool that permits a tailored therapy to be obtained, sparing healthy tissue and so minimizing potential damages to at-risk organs. Absorbed dose represents a reliable indicator of biological response due to its correlation to tissue irradiation effects. The present paper aims to focus attention on iodine therapy for DTC treatment and has developed due to the urgent need for standardization in procedures, since no unique approaches are available. This review aims to summarize new proposals for a dosimetry-based therapy and so explore new alternatives that could provide the possibility to achieve more tailored therapies, minimizing the possible side effects of radioiodine therapy for Differentiated Thyroid Cancer.

Ultrasonography of the thyroid, parathyroids, and beyond

Background

Ultrasonography has become an essential tool for the evaluation and management of thyroid and parathyroid diseases. Its applications extend beyond neck endocrine conditions to a multitude of pathologies within the head and neck region.

Objectives

Our study aimed to: (1) provide a broad review of neck ultrasonography and key findings in neck endocrine diseases; (2) support skilled performance office-based diagnostic ultrasonography and its varied applications.

Materials and methods

A review of the current literature was supplemented with clinical examples of key ultrasonographic findings.

Results

Current applications and key findings of ultrasonography in the diagnosis and management of neck endocrine conditions are reviewed.

Conclusion

Ultrasonography is a fundamental component in the evaluation and management of neck endocrine diseases. The reader is encouraged to use this review to enhance office-based performance and application of ultrasonography.

Video online

The online version of this article contains 11 additional videos. They are provided to illustrate some of the dynamic aspects of US performance. The article and the videos are available online (10.1007/s00106-022-01162-0). The videos can be found in the article back matter as “Electronic Supplementary Material”.

Quality of life after sialendoscopy: prospective non-randomized study

BACKGROUND

The symptomatic (swelling and pain) salivary gland obstructions are caused by sialolithiasis and salivary duct stenosis, negatively affecting quality of life (QOL), with almost all candidates for clinical measures and minimally invasive sialendoscopy. The impact of sialendoscopy treatment on the QOL has been little addressed nowadays. The objective is to prospectively evaluate the impact of sialendoscopy on the quality of life of patients undergoing sialendoscopy due to benign salivary obstructive diseases, measured through QOL questionnaires of xerostomia degree, the oral health impact profile and post sialendoscopy satisfaction questionnaires.

RESULT

37 sialendoscopies were included, most young female; there were 64.5% sialolithiasis and 35.4% post-radioiodine; with 4.5 times/week painful swelling symptoms and 23.5 months symptom duration. The pre- and post-sialendoscopy VAS values were: 7.42 to 1.29 (p < 0.001); 86.5% and 89.2% were subjected to sialendoscopy alone and endoscopic dilatation respectively; 80.6% reported improved symptoms after sialendoscopy in the sialolithiasis clinic (p < 0.001). The physical pain and psychological discomfort domain scores were mostly impacted where sialendoscopy provided relief and improvement (p < 0.001). We found a positive correlation between sialendoscopy and obstructive stone disease (p < 0.001) and no correlation in sialendoscopy satisfaction in xerostomia patients (p = 0.009).

CONCLUSIONS

We found improved symptoms with overall good satisfaction after sialendoscopy correlated with stones; and a negative correlation between xerostomia. Our findings support the evident indication of sialendoscopy for obstructive sialolithiasis with a positive impact on QOL and probably a relative time-dependent indication for stenosis/other xerostomia causes that little improved QOL satisfaction.

LEVEL OF EVIDENCE

2b-Prospective non-randomized study.

TRIAL REGISTRATION

WHO Universal Trial Number (UTN): U1111-1247-7028; Brazilian Clinical Trials Registry (ReBeC): RBR-6p8zfs.

Alterations in Oral Microbiota of Differentiated Thyroid Carcinoma Patients With Xerostomia After Radioiodine Therapy

BACKGROUND AND AIMS

Oral xerostomia remains one of the most common complications of differentiated thyroid carcinoma patients (DTC) after radioiodine therapy (RAI). Environmental factors in the etiology of xerostomia are largely unknown. We aimed to characterize the oral microbiota signatures and related biological functions associated with xerostomia and identify environmental factors affecting them.

METHODS

Saliva was collected from 30 DTC patients with xerostomia (XAs), 32 patients without xerostomia (indicated as non-XAs) following RAI after total thyroidectomy, and 40 healthy people (HCs) for 16S rRNA sequencing analysis.

RESULTS

The oral microbiota of XAs and non-XAs exhibited significant differences in α and β diversities and bacterial taxa. The abundance of porphyromonas, fusobacterium, and treponema_2 were significantly higher in XAs, while the abundance of the streptococcus was lower in the microbiota of non-XAs. Fusobacterium, and porphyromonas were negatively correlated with unstimulated/stimulated whole salivary secretion (USW)/(SWS), while fusobacterium, porphyromonas, and treponema_2 genera levels were positively associated with cumulative radioiodine dose. PICRUSt2 and BugBase suggested a significant difference in the expression of potentially_pathogenic, anaerobic, gram_negative, the arachidonic acid metabolism, and lipopolysaccharide (LPS) biosynthesis between XAs and non-XAs, possibly interdependent on radioiodine-induced inflammation. NetShift analysis revealed that porphyromonas genus might play as a key driver during the process of xerostomia. Five genera effectively distinguished XAs from non-XAs (AUC = 0.87).

CONCLUSION

Our study suggests for the first time that DTC patients with xerostomia after RAI display microbiota profiles and associated functional changes that may promote a pro-inflammatory environment. Dysbiosis of the oral microbiota may contribute to exacerbating the severity of xerostomia. Our results provide a research direction of the interaction mechanism between oral microbiota alteration and the progress of xerostomia.

Prevention of salivary gland dysfunction in patients treated with radioiodine for differentiated thyroid cancer: A systematic review of randomized controlled trials

INTRODUCTION

Salivary gland dysfunction (e.g., sialadenitis and xerostomia) is the most common complication of radioactive iodine (RAI) therapy for differentiated thyroid cancer (DTC). Several methods have been used to reduce/prevent this adverse effect. We aimed to systematically review the effectiveness of non-pharmacological and pharmacological interventions in preventing RAI-induced salivary gland dysfunction in patients with DTC.

METHODS

A systematic review was conducted, according to PRISMA guidelines. The protocol was registered (PROSPERO: CRD42022295229). PubMed, Embase, Scopus, and the Cochrane Library electronic databases were searched from inception to November 2021. Inclusion criteria were randomized controlled trials of DTC patients who were older than 18 years and underwent RAI after thyroidectomy in which at least one studied group received an intervention to prevent salivary gland dysfunction.

RESULTS

Twelve studies (a total of 667 participants) were included. Among DTC patients who were treated with RAI, nonpharmacological treatment such as parotid gland massage and aromatherapy ameliorated salivary gland dysfunction. Antioxidants such as vitamin E and selenium demonstrated radioprotective effects on the salivary gland, while other antioxidants did not show radioprotective benefits. Vitamin C showed no significant effects on preventing salivary gland dysfunction. Amifostine had inconsistent outcomes among studies. Among cholinergic agonists, pilocarpine did not demonstrate the radioprotective effect on parotid glands, while bethanechol lowered salivary gland dysfunction. However, the negative results from pilocarpine may be explained by the strong sialorrheic effect of the Cincinnati regimen in both study arms.

CONCLUSION

Among non-pharmacological and pharmacological methods, parotid gland massage, aromatherapy, vitamin E, selenium, amifostine, and bethanechol may have benefits in minimizing RAI-induced salivary gland dysfunction in patients with DTC. The results are limited by a small number of patients and should be confirmed in future larger randomized controlled trials.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=295229, PROSPERO, identifier CRD42022295229.

Use of Salivary Iodine Concentrations to Estimate the Iodine Status of Adults in Clinical Practice

BACKGROUND

Measurement of the 24-h urinary iodine concentration or urinary iodine excretion (UIE) is the gold standard to determine iodine status; however, this method is inconvenient. The use of salivary iodine could be a possible alternative since salivary glands express the sodium-iodine symporter.

OBJECTIVES

We aimed to establish the correlation between the salivary iodine secretion and UIE, to evaluate the clinical applicability of the iodine saliva measurement.

METHODS

We collected 24-h urine and saliva samples from 40 participants ≥18 y: 20 healthy volunteers with no specific diet (group 1), 10 patients with differentiated thyroid cancer with a low dietary intake (<50 μg/d, group 2), and 10 patients with a high iodine status as the result of the use of amiodarone (group 3). Urinary and salivary iodine were measured using a validated inductively coupled plasma MS method. To correct for differences in water content, the salivary iodine concentration (SIC) was corrected for salivary protein and urea concentrations (SI/SP and SI/SU, respectively). The intra- and inter-individual CVs were calculated, and the Kruskal-Wallis test and Spearman's correlation were used.

RESULTS

The intra-individual CVs for SIC, SI/SP, and SI/SU were 63.8%, 37.7%, and 26.9%, respectively. The inter-individual CVs for SIC, SI/SP, and SI/SU were 77.5%, 41.6% and 47.0%, respectively. We found significant differences (P < 0.01) in urinary and salivary iodine concentrations between all groups [the 24-h UIE values were 176 μg/d (IQR, 96.1-213 μg/d), 26.0 μg/d (IQR, 22.0-37.0 μg/d), and 10.0*103 μg/d (IQR, 7.57*103-11.4*103 μg/d) in groups 1-3, respectively; the SIC values were 136 μg/L (IQR, 86.3-308 μg/L), 71.5 μg/L (IQR, 29.5-94.5 μg/L), and 14.3*103 μg/L (IQR, 10.6*103-25.6*103 μg/L) in groups 1-3, respectively]. Correlations between the 24-h UIE and SIC, SI/SP, and SI/SU values were strong (ρ = 0.80, ρ = 0.90, and ρ = 0.86, respectively; P < 0.01).

CONCLUSIONS

Strong correlations were found between salivary and urinary iodine in adults with different daily iodine intakes. A salivary iodine measurement can be performed to assess the total iodine body pool, with the recommendation to correct for salivary protein or urea.

The effect of eating on the uptake of PSMA ligands in the salivary glands

Rationale

PSMA-directed therapy for metastatic prostate cancer is gaining adoption as a treatment option. However, accumulation of ¹⁷⁷Lu/²²⁵Ac-PSMA in the salivary glands remains a problem, with risk of dose-limiting xerostomia and potentially severe effect on the quality of life. Gustatory stimulation is an approach that has commonly been used in radioactive iodine therapy to reduce accumulation in the salivary glands. However, based on theoretical differences in biodistribution, it was hypothesized that this could potentially lead to adverse increased toxicity for PSMA-ligand therapy. The primary objective of this work was to determine if gustatory stimulation by eating an assortment of sweet/fatty/acidic foods during the biodistribution phase of [¹⁸F]DCFPyl could result in a clinically relevant (> 30%) change in the uptake of the tracer in the salivary glands.

Methods

10 patients who already received a whole-body [¹⁸F]DCFPyl PET/CT scan for evaluation of prostate cancer, underwent a repeat (intervention) PET/CT scan within a month of the first (control) scan. During the intervention scan, patients chose from an assortment of sweet/fatty/acidic foods, which they then chewed and swallowed for a period of time starting 1 min before tracer administration to 10 min thereafter. Data from both scans were analyzed by placing VOIs on the major salivary glands and segmenting them using relative thresholds.

Results

A slight increase in PSMA uptake in the parotid glands was observed on the intervention scan when compared to the baseline scan (+ 7.1% SUL_mean and + 9.2% SUL_max, p < 0.05). No significant difference in PSMA uptake in the submandibular glands was seen.

Conclusions

Eating only slightly increases uptake of [¹⁸F]DCFPyl in the parotid glands. We nonetheless recommend refraining from gustatory stimulation during the administration and early biodistribution phase of radionuclide therapy with PSMA-ligands to reduce the risk of avoidable additional toxicity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13550-021-00838-y.

Whole-Body Radioiodine Effective Half-Life in Patients with Differentiated Thyroid Cancer

Background: Radioactive 131I (RAI) therapy is used in patients with differentiated thyroid cancer (DTC) after total thyroidectomy for remnant ablation, adjuvant treatment or treatment of persistent disease. 131I retention data, which are used to indicate the time at which a 131I treated DTC patient can be released from the hospital, may bring some insights regarding clinical factors that prolong the length of hospitalization. The aim of this study was to investigate the 131I whole-body retention in DTC patients during 131I therapy. Methods: We monitored 166 DTC patients to follow the 131I whole-body retention during 131I therapy with a radioactivity detector fixed on the ceiling of each protected room. A linear regression fit permitted us to estimate the whole-body 131I effective half-life in each patient, and a relationship was sought between patients' clinical characteristics and whole-body effective 131I half-life. Results: The effective 131I half-life ranged from 4.08 to 56.4 h. At multivariable analysis, longer effective 131I half-life was related to older age and extensive extra-thyroid disease. Conclusions: 131I effective half-life during 131I treatment in DTC patients is highly variable among patients and is significantly longer in older and in patients with RAI uptake in large thyroid remnants or in extrathyroidal disease that significantly prolongs the whole-body retention of 131I.

A pretest-posttest pilot study for the development and preliminary validation of a tool for the clinical assessment of radioiodine induced sialadenitis

Objectives:

The clinical assessment of radioiodine-induced sialadenitis is relied on the observer-defined toxicity grading model. However, this model has significant limitations, the major one being the lack of systematic assessment based on objective criteria. The main aim of this study was the development and testing of an assessment tool which could examine the severity of post-irradiation sialadenitis.

Methods:

The development of the Sialadenitis Assessment Tool proceeded through three phases. The first and second phases included a literature review and the development of the tool which derived from the review, respectively. The third phase involved a pilot testing of the Assessment Tool to a sample of 34 patients undergoing I¹³¹ therapy. The assessment was carried out by two independent healthcare professionals, pre- and post-radioiodine therapy. The results of the assessment tool were compared with other scales, including the DIRIX and EORTC H&N35.

Results:

According to the Cohen’s kappa test, the Sialadenitis Assessment Tool is a reliable tool for the assessment of sialadenitis (Cohen’s κ = 1). The concurrent and internal validity tests showed a tendency of association with most variables (p < 0.001) in the DIRIX and EORTC QLQ-HN35 scales.

Conclusion:

Preliminary evidence show that Sialadenitis Assessment Tool is a valid and reliable tool to assess radioiodine-induced sialadenitis in patients undergoing I¹³¹ therapy post-thyroidectomy.

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.

PSMA PET/CT Identifies Intrapatient Variation in Salivary Gland Toxicity From Iodine-131 Therapy

Introduction:

Xerostomia is a well-known complication after iodine-131 (¹³¹I) therapy for thyroid carcinoma. It is currently insufficiently understood how the dose and biodistribution of ¹³¹I relates to salivary gland toxicity, and whether this is consistent for all salivary glands within a single patient. Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) was recently introduced as a new tool to evaluate the relative loss of vital acinar cells in individual salivary glands. We aimed to assess gland-specific salivary gland toxicity after ¹³¹I-therapy using PSMA PET/CT.

Methods:

Five patients with differentiated thyroid cancer underwent [⁶⁸Ga]Ga-PSMA-11 PET/CT to evaluate their eligibility for peptide radioligand therapy with [¹⁷⁷Lu]Lu-PSMA-617. Uptake patterns in salivary glands were evaluated visually and quantitatively as an indicator of vital acinar cell loss after prior ¹³¹I-therapy.

Results:

Four of 5 patients demonstrated significant lowered uptake in at least one salivary gland, after receiving at least 2 ¹³¹I-treatments. Asymmetric loss of vital acinar cells occurred by gland type (parotid/submandibular) and location (right/left). The other salivary glands in these patients and all salivary glands in the fifth patient showed normal uptake, demonstrating high intrapatient and interpatient variability.

Conclusions:

¹³¹I-therapy can induce salivary gland toxicity with high inter- but also high intrapatient variation among separate gland locations, which can be assessed with PSMA PET/CT. This new technique offers potential to guide further development and evaluation of protective measures in patients receiving ¹³¹I-therapy.

Radioiodine therapy induced sialadenitis versus chronic idiopathic sialadenitis-Presentation and outcomes

BACKGROUND

This study explores the unique characters of high dose radioactive iodine (RAI) induced chronic sialadenitis.

METHODS

A retrospective study of patients having received salivary endoscopy and followed in our outpatient clinic.

RESULTS

A total of 100 patients met the inclusion criteria, 75 were diagnosed with chronic idiopathic sialoadenitis and 25 with radio-iodine induced sialoadenitis (RIS). The main complaint in both groups was swelling of the parotid gland. Pain, dysphagia, and xerostomia were observed considerably more in the RIS group. During sialo-endoscopy, fibrosis of the Stensen's duct was more common in the RIS group (p = 0.003). RIS patients group generally managed better with interventional endoscopic treatment alone (80% vs. 46%).

CONCLUSION

RIS patients have distinct clinical characteristics. There may be a collateral muscular damage to the masticatory muscles. Fibrosis and parenchymal damage are major findings during sialendoscopy. Sialendoscopy is a safe and efficient treatment for RAI induced sialadenitis.

Disease-Induced Changes in Salivary Gland Function and the Composition of Saliva

Although the physiological control of salivary secretion has been well studied, the impact of disease on salivary gland function and how this changes the composition and function of saliva is less well understood and is considered in this review. Secretion of saliva is dependent upon nerve-mediated stimuli, which activate glandular fluid and protein secretory mechanisms. The volume of saliva secreted by salivary glands depends upon the frequency and intensity of nerve-mediated stimuli, which increase dramatically with food intake and are subject to facilitatory or inhibitory influences within the central nervous system. Longer-term changes in saliva secretion have been found to occur in response to dietary change and aging, and these physiological influences can alter the composition and function of saliva in the mouth. Salivary gland dysfunction is associated with different diseases, including Sjögren syndrome, sialadenitis, and iatrogenic disease, due to radiotherapy and medications and is usually reported as a loss of secretory volume, which can range in severity. Defining salivary gland dysfunction by measuring salivary flow rates can be difficult since these vary widely in the healthy population. However, saliva can be sampled noninvasively and repeatedly, which facilitates longitudinal studies of subjects, providing a clearer picture of altered function. The application of omics technologies has revealed changes in saliva composition in many systemic diseases, offering disease biomarkers, but these compositional changes may not be related to salivary gland dysfunction. In Sjögren syndrome, there appears to be a change in the rheology of saliva due to altered mucin glycosylation. Analysis of glandular saliva in diseases or therapeutic interventions causing salivary gland inflammation frequently shows increased electrolyte concentrations and increased presence of innate immune proteins, most notably lactoferrin. Altering nerve-mediated signaling of salivary gland secretion contributes to medication-induced dysfunction and may also contribute to altered saliva composition in neurodegenerative disease.

The Side Effects of Therapeutic Radioiodine-131 on the Structure of Enamel and Dentin in Permanent Human Teeth

Simple Summary

Our research suggest radioiodine-131 used for differentiated thyroid carcinomas has an impact on the oral health of patients. We found that alteration of dental hard tissues starts after 6 h post-radioiodine administration. These findings highlight the importance of the multidisciplinary team management in the quality of life of the oncological patient.

Abstract

Radioiodine-131 (I-131) is an essential therapy for patients with differentiated thyroid carcinomas (DTC). Generally, I-131 is safe and well tolerated, but patients may present early or late complications in the oral and maxillofacial areas. Thus, the aim of this study was to evaluate in-vitro, the alteration of enamel and dentin after I-131 exposure using histopathological assessment, scanning electron microscopy (SEM) and atomic force microscopy (AFM). For I-131 irradiation, an in-vitro protocol was used that simulates the procedure for irradiation therapy performed for patients with DTCs. A total of 42 teeth were divided into seven groups (n = 6) and irradiated as follows: control, irradiation groups (3, 6, 12, 36, 48 h, 8 days). Histological changes were observed at 48 h (enamel surface with multifocal and irregular areas) and at 8 days (enamel surface with multiple, very deep, delimited cavities). SEM imaging revealed the enamel destruction progresses along with the treatment time increasing. The alterations are extended into the enamel depth and the dislocated hydroxyapatite debris is overwhelming. The enamel-dentine interface shows small gaps after 6 h and a very well developed valley after 12 h; the interface microstructure resulted after 8 days is deeply altered. The AFM imaging shows that I-131 affects the protein bond between hydroxyapatite nano-crystals causing loss of cohesion, which leads to significant increasing of nano-particles diameter after 6 h. In conclusion, both enamel and dentin appear to be altered between 12 and 48 h and after 8 days of treatment are extended in depth.

Muscarinic inhibition of salivary glands with glycopyrronium bromide does not reduce the uptake of PSMA-ligands or radioiodine

RATIONALE

Salivary glands are highly perfused and express the prostate-specific membrane antigen (PSMA) receptor as well as the sodium-iodide symporter. As a consequence, treatment with ¹⁷⁷Lu/²²⁵Ac-PSMA for prostate cancer or ¹³¹I for thyroid cancer leads to a high radiation dose in the salivary glands, and patients can be confronted with persistent xerostomia and reduced quality of life. Salivation can be inhibited using an antimuscarinic pharmaceutical, such as glycopyrronium bromide (GPB), which may also reduce perfusion. The primary objective of this work was to determine if inhibition with GPB could provide a considerable (> 30%) reduction in the accumulation of administered ¹²³I or ⁶⁸Ga-PSMA-11 in salivary glands.

METHODS

Ten patients who already received a whole-body ⁶⁸Ga-PSMA-11 PET/CT scan for (re)staging of prostate cancer underwent a repeat PET/CT scan with tracer administration at 90 min after intravenous injection of 0.2 mg GPB. Four patients in follow-up after thyroid cancer, who had been treated with one round of ablative ¹³¹I therapy with curative intent and had no signs of recurrence, received ¹²³I planar scintigraphy at 4 h after tracer administration without GPB and a repeated scan at least one week later, with tracer administration at 30 min after intramuscular injection of 0.4 mg GPB. Tracer uptake in the salivary glands was quantified on PET and scintigraphy, respectively, and values with and without GPB were compared.

RESULTS

No significant difference in PSMA uptake in the salivary glands was seen without or with GPB (Mean SUL_mean parotid glands control 5.57, intervention 5.72, p = 0.50. Mean SUL_mean submandibular glands control 6.25, intervention 5.89, p = 0.12). Three out of 4 patients showed increased ¹²³I uptake in the salivary glands after GPB (Mean counts per pixel control 8.60, intervention 11.46).

CONCLUSION

Muscarinic inhibition of salivation with GPB did not significantly reduce the uptake of PSMA-ligands or radioiodine in salivary glands, and can be dismissed as a potential strategy to reduce toxicity from radionuclide therapies.

Evaluation of variation of saliva iodine and recommendations for sample size and sampling time: Implications for assessing iodine nutritional status

BACKGROUND

Saliva iodine concentration (SIC) has been found to be a good indicator of iodine nutritional status. However, limited information is available regarding saliva iodine characteristics.

AIMS

The study aimed to evaluate intra-day, intra-individual, and population SIC variation in order to provide information on optimal sample size and sampling time for assessing iodine nutritional status.

METHODS

Twenty-nine healthy school-aged students were recruited. Iodine intake from diet and water, and iodine excretion through urine and feces were assessed over a three-day period. Saliva samples were collected six times a day.

RESULTS

Diurnal variations were observed in SIC corresponding to iodine intake. The mean CV in SIC was lower than that for 24-hour urinary iodine concentration (24-h UIC) and 24-hour urinary iodine excretion (24-h UIE) not only at the individual level (42.73% vs. 47.71% and 49.69%) but also at the population level (71.29% vs. 100.43% and 72.49%). The number of saliva samples needed to estimate the iodine level with 95% CI within precision ranges of ±10%, ±20% was 55, 14 in an individual, and 180, 45 in a population. There was a good correlation between post-lunch SIC and total daily iodine intake.

CONCLUSIONS

Saliva iodine has utility for evaluating the recent iodine nutrition of individuals and populations. The variation in SIC was lower than that for 24-h UIC and 24-h UIE. Saliva may be preferred over urine because of its ease of collection. Fourteen samples are needed to assess individual iodine status and forty-five saliva samples for assessment of population iodine status with reasonable precision. We recommend that saliva samples be collected after 14:00 in a day.

Short-term bone marrow suppression in differentiated thyroid cancer patients after radioactive iodine treatment

After thyroidectomy in differentiated thyroid cancer (DTC), radioactive iodine (RAI) treatment is often used for remnant ablation. However, RAI treatment has been associated with bone marrow suppression, and leukopenia, anemia, and thrombocytopenia may occur after a single RAI administration. In this study, we examined the change in complete blood counts at 1 week after RAI administration; this is less well studied. A group of 189 DTC patients who received RAI treatment and underwent blood tests before and after treatment, were included. Peripheral blood counts at baseline were compared to those obtained at 1 week, 1-6 months, and 6-12 months after RAI treatment in order to test for bone marrow suppression. At 1 week after RAI treatment, there was a significant decrease in the white blood cell count (WBC, 5.8 ± 1.6 × 10⁹/L vs. 5.4 ± 1.5 × 10⁹/L, p < 0.001) and hemoglobin level (Hb, 13.5 ± 1.7 g/dL vs. 13.3 ± 1.4 g/dL, p = 0.001). The WBC decrease was mostly due to lymphocyte counts (2.2 ± 0.6 × 10⁹/L vs. 1.6 ± 0.5 × 10⁹/L, p < 0.001), with no decrease in the neutrophil count. Although not significantly changed at 1 week, platelets counts were altered within 6 months (265 ± 69 × 10⁹/L vs. 239 ± 53 × 10⁹/L, p < 0.001). The decline in the WBC count recovered within 6 months; lymphocyte and platelet counts recovered within 12 months. In conclusion, RAI treatment after a thyroidectomy was associated with a statistically significant but temporary decline in WBC counts and Hb levels at 1 week. Physicians treating DTC patients should not decrease usage of moderate dose RAI treatments.

Sialographic Analysis of Radioiodine-Associated Chronic Sialadenitis

OBJECTIVES/HYPOTHESIS

To apply a novel sialography classification system to identify parotid and submandibular ductal findings following I-131 therapy and to assess correlates to dose and duration of symptoms.

STUDY DESIGN

Retrospective single-center case series.

METHODS

Patients who underwent sialography between February 2008 and February 2019 after previously receiving I-131 treatment were identified via a retrospective chart review. Their sialograms were systematically evaluated and scored by applying the Iowa parotid sialogram scale to also include submandibular gland analysis.

RESULTS

From 337 sialograms, 30 (five submandibular, 25 parotid) underwent analysis. Ductal stenosis was identified in all sialograms and was graded as moderate (>50%-75%) in 7/30 cases and severe (>75%) in 15/30 cases. The distal (main) duct was narrowed in 23/30 cases. No association was identified between degree of ductal stenosis and I-131 dose (P = .39), age (P = .81), or time from I-131 therapy to sialogram (P = .97).

CONCLUSIONS

The Iowa parotid sialogram scale was successfully applied to report abnormalities of the parotid and submandibular ductal system. The most common manifestation of I-131-associated sialadenitis was a severe stenosis within the distal salivary duct. No statistically significant association was found between degree of ductal stenosis and dose of I-131, age, or duration of symptoms.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E1450-E1456, 2021.

Disorders of Dental Hard Tissues Induced by Radioiodine-131 (I-131) Therapy Used in Differentiated Thyroid Cancer: An In Vitro Study

This study aimed to evaluate, in vitro, the effects of I-131 on enamel and dentin in healthy human incisive permanent maxillary teeth. Our in vitro model analogue with the in vivo conditions of differentiated thyroid carcinoma patients treated with I-131, consisted in a solution of I-131 dissolved in artificial saliva. A total of 48 teeth were divided into eight groups (n = 6): control, irradiation groups at 3, 6, 12, 24, 36, 48, and 192 h, respectively. At the end of radiation exposure, radioiodine activity of specimens was assessed. Fine microstructure, nanostructure, surface roughness, and hidroxyapatite (HAP) crystallite diameter were investigated by atomic force microscopy (AFM) to both enamel and dentin structures. There is a constant increase of radioactivity in dental structures at 3, 6, 12, 24 h, due to progressive retention and I-131 migration, with a maximum at 36 h. Enamel showed notable alterations, which was correlated with the increase of the treatment time. A relevant visible distance between the HAP prisms was observed after 24 h. The surface suffered a loss in its compact structure. I-131 acts in the same way on HAP crystallites in dentin as in those in enamel. It was noticed that their morpho-dimensional changes occurred only after 12 h of treatment. Radioiodine-131 determines degradation of enamel and dentin by starting from the alteration of the crystalline network of HAP prisms, transforming them from compact materials into an agglomeration of rocky submicron structures.

Radioiodine-Induced Salivary Gland Damage Detected by Ultrasonography in Patients Treated for Papillary Thyroid Cancer: Radioactive Iodine Activity and Risk

Background: An important side effect of radioactive iodine (RAI) therapy in patients treated for papillary thyroid cancer (PTC) is chronic sialadenitis. Neck ultrasonography (US) easily recognizes radioiodine-induced salivary gland abnormalities. The objectives of this study were to determine the prevalence of US-detected sialadenitis caused by RAI and to identify the risk factors associated with this damage. Methods: This nonconcurrent cohort study includes all PTC-operated patients who were treated with RAI between 2007 and 2017 and were systematically evaluated with preoperative and follow-up neck US that included targeted exploration of the major salivary glands. Patients with pre-existing salivary gland diseases were excluded. The anatomical damage (diminished glandular volume, wavy contours, hypoechogenicity, and heterogeneity) was qualitatively assessed and compared with the preoperative study. RAI activity, sex, age, and preparation method were evaluated as risk factors using univariate and multivariate analyses with logistic regression. Results: Enrolled in this study were 570 patients who received a median RAI activity of 3700 MBq (100 mCi). On US, we found 143 patients (25.1%) with damage in at least one of their salivary glands: all had parotid damage (77 bilaterally) and 14 (9.8%) also had submandibular gland damage (7 of them bilaterally). The multivariate analysis indicated that the risk of sialadenitis was significantly (p < 0.01) correlated with both RAI activity and sex (14.1% of males vs. 28.5% of females). However, the main risk factor was RAI activity; no injury was detected in 156 patients who received 1110 MBq (30 mCi) and 1850 MBq (50 mCi) of RAI. In the groups of patients receiving 3700 MBq (100 mCi), 5550 MBq (150 mCi) and ≥7400 MBq (≥200 mCi), atrophy was found in 21%, 46.9%, and 77.7% of patients, respectively. Age and preparation method were not related to an increased risk of atrophy in this study. Conclusions: Chronic sialadenitis is common and affects approximately one fourth of patients who receive 3700 MBq (100 mCi) or higher RAI activity. The main risk factor for this injury is the total RAI activity administered. By using the lowest effective activity possible, irreversible anatomical damage in salivary glands can be minimized. US is an excellent tool to diagnose post-RAI atrophy.

Saliva Iodine Concentration in Children and Its Association with Iodine Status and Thyroid Function

CONTEXT

The effectiveness of saliva iodine concentration (SIC) in evaluating iodine status in children is not clear.

OBJECTIVE

We aimed to explore associations between SIC and assessed indicators of iodine status and thyroid function.

DESIGN

Cross-sectional study.

SETTING

Primary schools in Shandong, China.

PARTICIPANTS

Local children aged 8 to 13 years with no known thyroid disease were recruited to this study.

MAIN OUTCOME MEASURES

Blood, saliva, and urine samples were collected to evaluate thyroid function and iodine status.

RESULTS

SIC positively correlated with spot urinary iodine concentration (r = 0.29, P < 0.0001), 24-hour urinary iodine concentration (r = 0.35, P < 0.0001), and 24-hour urinary iodine excretion (r = 0.40, P < 0.0001). The prevalence of thyroid nodules (TN) and goiter showed an upward trend with SIC quantiles (P for trend < 0.05). Children with SIC <105 μg/L had a higher risk of insufficient iodine status (OR = 4.18; 95% CI, 2.67-6.56) compared with those with higher SIC. Those having SIC >273 μg/L were associated with greater risks of TN (OR = 2.70; 95% CI, 1.38-5.26) and excessive iodine status (OR = 18.56; 95% CI, 5.66-60.91) than those with lower SIC values.

CONCLUSIONS

There is a good correlation between SIC and urinary iodine concentrations. It is of significant reference value for the diagnosis of iodine deficiency with SIC of less than 105 μg/L and for the diagnosis of iodine excess and TN with SIC of more than 273 μg/L. Given the sanitary nature and convenience of saliva iodine collection, SIC is highly recommended as a good biomarker of recent iodine status in school-aged children.

Sialoscintigraphy - Shopworn or Bestselling? A Traditional Procedure with New Prominent Role in Theranostics and Immuno-Oncology

Sialoscintigraphy has been used in nuclear imaging for almost sixty years. It allows functional assessment and quantification of all large salivary glands. Physiological function of the salivary glands is essential for the preservation of the oral mucosa, the sense of taste and dental health. Impaired salivary gland function may lead to reduced or even absent salivation resulting in various complaints such as loss of taste reducing quality of life. During the recent years clinical relevance of assessment of salivary gland function has been rising. As novel radiopharmaceuticals such as 225Ac-PSMA or 177Lu-PSMA may cause damage to the salivary glands in a subset of patients, reliable methods for quantification of salivary gland function are vital for therapy planning and follow-up. Standardized protocols for the implementation and interpretation of this procedure are necessary to achieve comparable results from individual theranostic centers and to facilitate multicenter trials. Sialocintigraphy is also of clinical relevance for immunooncology. Treatments with checkpoint inhibitors such as Ipilimumab or Nivulomab frequently cause autoimmune disorders affecting the salivary glands that may lead to reduced production of saliva and finally loss of taste. Therefore, standardized procedure protocols for sialoscintigraphy are also important for general oncology.Here we suggest a protocol for sialoscintigraphy that may be used as standard in centers for theranostics or immunooncology and discuss the potential future role of this traditional procedure.

Clinical Outcomes of N1b Papillary Thyroid Cancer Patients Treated with Two Different Doses of Radioiodine Ablation Therapy

BACKGROUND

The optimal dose of radioactive iodine (RAI) therapy for N1b papillary thyroid carcinoma (PTC) is controversial. We evaluated the clinical outcome of N1b PTC patients treated with either 100 or 150 mCi of RAI.

METHODS

We retrospectively analyzed N1b PTC patients who underwent total thyroidectomy and postoperative RAI therapy at a tertiary referral center between 2012 and 2017. As the baseline characteristics differed between treatment groups, we performed exact matching for various pathological factors according to RAI dose. We evaluated the response to therapy and recurrence-free survival (RFS) in the matched patients. Structural recurrent/persistent disease was defined as new structural disease detected after initial therapy, which was confirmed by cytology or pathology.

RESULTS

Of the total 436 patients, 37 (8.5%) received 100 mCi of RAI and 399 (91.5%) received 150 mCi of RAI. After an exact 1:3 matching, 34 patients in the 100 mCi group and 100 patients in the 150 mCi group remained. There was no significant difference in response to therapy between the groups in the matched population (P=0.63). An excellent response was achieved in 70.6% (n=24) of patients in the 100 mCi group and 76.0% (n=76) in the 150 mCi group. Two (5.9%) patients in the 100 mCi group and four (4.0%) in the 150 mCi group had recurrence and there was no significant difference in RFS between the groups in the matched population (P=0.351).

CONCLUSION

There were no differences in response to therapy and RFS in N1b PTC patients according to RAI dose.

Salivary and lacrimal dysfunction after radioactive iodine for differentiated thyroid cancer: American Head and Neck Society Endocrine Surgery Section and Salivary Gland Section joint multidisciplinary clinical consensus statement of otolaryngology, ophthalmology, nuclear medicine and endocrinology

BACKGROUND

Postoperative radioactive iodine (RAI) administration is widely utilized in patients with differentiated thyroid cancer. While beneficial in select patients, it is critical to recognize the potential negative sequelae of this treatment. The prevention, diagnosis, and management of the salivary and lacrimal complications of RAI exposure are addressed in this consensus statement.

METHODS

A multidisciplinary panel of experts was convened under the auspices of the American Head and Neck Society Endocrine Surgery and Salivary Gland Sections. Following a comprehensive literature review to assess the current best evidence, this group developed six relevant consensus recommendations.

RESULTS

Consensus recommendations on RAI were made in the areas of patient assessment, optimal utilization, complication prevention, and complication management.

CONCLUSION

Salivary and lacrimal complications secondary to RAI exposure are common and need to be weighed when considering its use. The recommendations included in this statement provide direction for approaches to minimize and manage these complications.

Clinical and Sialographic Imaging Features of 131I Radiation-induced Submandibular Gland Sialadenitis

PURPOSE

¹³¹I radiation-induced sialadenitis is the most frequent complication of ¹³¹I treatment for papillary thyroid carcinoma, but little is known about ¹³¹I radiation-induced submandibular gland sialadenitis. The purpose of this study was to compare and contrast the clinical and sialographic imaging features of ¹³¹I radiation-induced submandibular gland sialadenitis to ¹³¹I radiation-induced parotitis.

PATIENTS AND METHODS

This retrospective cross-sectional study included patients with ¹³¹I radiation-induced submandibular gland sialadenitis and parotitis. Clinical records and sialographic image features were evaluated. The predictor variables included age at the time of diagnosis, gender, course of the disease, site of symptoms, and sialographic image grades. The outcome variable was the location of sialadenitis. A student t-test was conducted to analyze the associations between predictor variables and the outcome.

RESULTS

The sample was composed of 4 patients with submandibular gland sialadenitis (100% female), 28 with parotitis (85.7% female), and 1 with submandibular gland sialadenitis and parotitis (P < .05). The occurrence of bilateral glands dysfunction was less often in submandibular glands (SMG: 1/4; PG: 19/28). The age and course of disease were not different between submandibular gland sialadenitis and parotitis (Age, SMG: 46.00 ± 13.59 years; PG: 50.04 ± 10.71 years, P > .05; Course of the disease, SMG: 11.00 ± 16.69 months; PG: 6.96 ± 11.18 months, P > .05). Radiographically, 7 of 16 patients with parotitis were identified as grade 2 and 9 patients as grade 3. In 3 patients with submandibular gland sialadenitis, 1 patient was identified as grade 2 and 2 patients as grade 3. The postoperative pathological results showed that the proliferation of glandular tissue from the hilum of the submandibular gland caused duct stenosis.

CONCLUSION

The results suggest ¹³¹I radiation-induced submandibular gland sialadenitis has a lower incidence compared with parotitis and ¹³¹I radiation-induced submandibular gland sialadenitis might be related to duct stenosis caused by proliferative glandular tissue after ¹³¹I radiation treatment.

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.

The revised clinical practice guidelines on the management of thyroid tumors by the Japan Associations of Endocrine Surgeons: Core questions and recommendations for treatments of thyroid cancer

The Japan Associations of Endocrine Surgeons has developed the revised version of the Clinical Practice Guidelines for Thyroid Tumors. This article describes the guidelines translated into English for the 35 clinical questions relevant to the therapeutic management of thyroid cancers. The objective of the guidelines is to improve health-related outcomes in patients with thyroid tumors by enabling users to make their practice evidence-based and by minimizing any variations in clinical practice due to gaps in evidential knowledge among physicians. The guidelines give representative flow-charts on the management of papillary, follicular, medullary, and anaplastic thyroid carcinoma, along with recommendations for clinical questions by presenting evidence on the relevant outcomes including benefits, risks, and health conditions from patients' perspective. Therapeutic actions were recommended or not recommended either strongly (◎◎◎ or XXX) based on good evidence (😊)/good expert consensus (+++), or weakly (◎, ◎◎ or X, XX) based on poor evidence (😣)/poor expert consensus (+ or ++). Only 10 of the 51 recommendations given in the guidelines were supported by good evidence, whereas 35 were supported by good expert consensus. While implementing the current guidelines would be of help to achieve the objective, we need further clinical research to make our shared decision making to be more evidence-based.

Protective Effect of Alpha-Lipoic Acid on Salivary Dysfunction in a Mouse Model of Radioiodine Therapy-Induced Sialoadenitis

Radioiodine (RI) therapy is known to cause salivary gland (SG) dysfunction. The effects of antioxidants on RI-induced SG damage have not been well described. This study was performed to investigate the radioprotective effects of alpha lipoic acid (ALA) administered prior to RI therapy in a mouse model of RI-induced sialadenitis. Four-week-old female C57BL/6 mice were divided into four groups (n = 10 per group): group I, normal control; group II, ALA alone (100 mg/kg); group III, RI alone (0.01 mCi/g body weight, orally); and group IV, ALA + RI (ALA at 100 mg/kg, 24 h and 30 min before RI exposure at 0.01 mCi/g body weight). The animals in these groups were divided into two subgroups and euthanized at 30 or 90 days post-RI treatment. Changes in salivary ^99mTc pertechnetate uptake and excretion were tracked by single-photon emission computed tomography. Salivary histological examinations and TUNEL assays were performed. The ^99mTc pertechnetate excretion level recovered in the ALA treatment group. Salivary epithelial (aquaporin 5) cells of the ALA + RI group were protected from RI damage. The ALA + RI group exhibited more mucin-containing parenchyma and less fibrotic tissues than the RI only group. Fewer apoptotic cells were observed in the ALA + RI group compared to the RI only group. Pretreatment with ALA before RI therapy is potentially beneficial in protecting against RI-induced salivary dysfunction.

Scintigraphic evaluation of salivary gland function in thyroid cancer patients after radioiodine remnant ablation

Radioiodine (¹³¹I, RAI) has traditionally been used in thyroid cancer treatment but its benefit should be balanced against possible risks. Among them, salivary gland dysfunction has often been discussed, although the reported data have been inconsistent. The aim of our prospective study was to evaluate salivary gland function in 31 thyroidectomised patients (6 men, 25 women; median age 52 yr) before and 4–6 months after RAI remnant ablation (RRA), using activity of 3.7 GBq ¹³¹I‐NaI. Salivary gland uptake and excretion fractions were quantitatively assessed with ^99mTc – pertechnetate salivary gland scintigraphy. Pre‐ and post‐treatment values were compared using Wilcoxon signed rank test. No statistically significant difference in the pre‐ and post‐treatment values was observed in parotid or submandibular glands uptake, or in the parotid or submandibular excretion fractions. The calculated power for minimum relevant difference of 25% with the sample size of 31 ranged between 86% and 96% for the individual variables, making our negative results reasonably reliable. The results suggest that RRA with the most commonly used activity of 3.7 GBq has no important impact on salivary gland function. Therefore, the concerns about putative salivary gland functional deterioration following RRA are probably unjustified.

MnTnBuOE-2-PyP treatment protects from radioactive iodine (I-131) treatment-related side effects in thyroid cancer

Treatment of differentiated thyroid cancer often involves administration of radioactive iodine (I-131) for remnant ablation or adjuvant therapy. However, there is morbidity associated with I-131 therapy, which can result in both acute and chronic complications. Currently, there are no approved radioprotectors that can be used in conjunction with I-131 to reduce complications in thyroid cancer therapy. It is well known that the damaging effects of ionizing radiation are mediated, in part, by the formation of reactive oxygen species (ROS). A potent scavenger of ROS, Mn(III)meso-tetrakis(N-n-butoxyethylpyridinium-2-yl)porphyrin (MnTnBuOE-2-PyP), has radioprotective and anti-tumor effects in various cancer models including head and neck, prostate, and brain tumors exposed to external beam radiation therapy. Female C57BL/6 mice were administered I-131 orally at doses of 0.0085-0.01 mCi/g (3.145 × 10⁵ to 3.7 × 10⁵ Bq) of body weight with or without MnTnBuOE-2-PyP. We measured acute external inflammation, blood cell counts, and collected thyroid tissue and salivary glands for histological examination. We found oral administration of I-131 caused an acute decrease in platelets and white blood cells, caused facial swelling, and loss of thyroid and salivary tissues. However, when MnTnBuOE-2-PyP was given during and after I-131 administration, blood cell counts remained in the normal range, less facial inflammation was observed, and the salivary glands were protected from radiation-induced killing. These data indicate that MnTnBuOE-2-PyP may be a potent radioprotector of salivary glands in thyroid cancer patients receiving I-131 therapy.

Early Sialadenitis After Radioactive Iodine Therapy for Differentiated Thyroid Cancer: Prevalence and Predictors

INTRODUCTION

Sialadenitis is a frequent occurrence after radioactive iodine therapy (RAI). However, reports on its predictors and risk factors in the Eastern Mediterranean Region (EMRO) are scarce.

AIM

This study aimed to identify risk factors for early sialadenitis in patients receiving RAI for differentiated thyroid cancer (DTC) at the American University of Beirut Medical Center. It also aimed to determine the prevalence and characteristics of such patients receiving RAI at our institution.

METHODS

This was a retrospective study conducted at the American University of Beirut Medical Center. Medical charts were reviewed for all patients 18-79 years of age admitted to receive RAI for DTC between 01/01/2012 and 31/12/2015. Sialadenitis was deemed present if there were any records of neck swelling/pain, dry mouth, or difficulty swallowing within 48 hours of RAI administration. Characteristics between patients with sialadenitis and those without were compared to determine predictors.

RESULTS

There were 174 patients admitted to receive RAI, predominantly females (71.3%), with papillary thyroid cancer (93.1%). The majority had lymph node involvement (64.5%). Pretreatment thyroid stimulating hormone (TSH) was greater than 75 mIU/ml in most patients (72.6%). The prevalence of sialadenitis was 20.1% (95% CI (15-27)). Being non-Lebanese and having a positive whole-body scan were associated with sialadenitis and persisted after adjustments (OR = 2.34 and 3.99). Non-Lebanese patients had higher rates of lymph nodes involvement (p value 0.005) and were kept off levothyroxine for longer periods (p value 0.02).

CONCLUSION

The prevalence of sialadenitis at our institution was similar to other reported studies from the world. However, risk factors allude to more iodine exposure in the neck with positive whole-body scan uptake, lymph node involvement, and prolonged period of hypothyroidism.

Ultrasonography Echotexture as a surrogate for Sialadenitis secondary to 131I Radioiodine Therapy for differentiated Thyroid Cancer: a review and metaanalysis

To systematically review and analyze the medical literature to assess ultrasonography echotexture changes in thyroid cancer patients for the detection of chronic sialadenitis caused by radioiodine therapy.

METHODS

Sources were retrieved from PubMed, Scopus, EMBASE and LILACS through November 2018. All studies that assessed ultrasonographic features before 131I administration and at 12 months after 131I administration were selected. After data extraction, statistical analysis was performed by using Stata software.

RESULTS

From a total of 435 studies, 4 studies involving 665 patients were considered eligible, and echotexture heterogeneity was found with a significant difference.

CONCLUSIONS

Ultrasound echotexture may detect chronic sialadenitis secondary to salivary radioiodine therapy.

Preliminary study on the efficacy of xerostomia treatment with sialocentesis targeting thyroid disease patients given radioiodine therapy

Background

Radioiodine therapy has been widely used for thyroid disease patients, but hyposalivation and xerostomia may occur in 10~30% of patients. Sialocentesis is a procedure that removes inflammatory substances in the salivary duct and expands the duct for the secretion and delivery of saliva. In this study, thyroid disease patients treated with radioactive iodine were selected among the patients with xerostomia who visited the hospital, and the effect of sialocentesis was compared and analyzed. And then, comparison between the radioiodine therapy-experienced group and the non-radioiodine therapy-experienced group was conducted.

Results

In this study, we studied xerostomia patients who underwent radioiodine therapy due to thyroid diseases and who underwent sialocentesis at the Korea University Anam Hospital. Sialocentesis is conducted by one surgeon. The study also compares the clinical symptoms before and after the surgery. After the procedure, the discomfort due to xerostomia was reduced, and the symptom was improved effectively.

Conclusions

The results of this study showed that sialocentesis has a clinical effect in the treatment of xerostomia, which is a side effect of radioiodine therapy. In addition, the possibility of further clinical application of sialocentesis in the future is found.

Clinical, Pathological, and Molecular Profiling of Radioactive Iodine Refractory Differentiated Thyroid Cancer

Background: Six to 20% of thyroid cancer (TC) patients develop distant metastases, and one-third become radioiodine refractory (RAIR). Available targeted therapies increase progression-free survival but are associated with toxicities. This study aims to characterize clinical, pathological, and molecular profiles of patients with RAIR TC. Methods: Data of TC patients seen during 2013-2017 at two tertiary care centers were retrospectively analyzed. Patients were considered RAIR according to American Thyroid Association guidelines. The control cohort was sex matched and age matched and had either regression or stable disease (by Response Evaluation Criteria in Solid Tumors) on follow-up at least three years after initial therapy. Molecular profiles on a subset of RAIR patients were reviewed. Results: Compared with 22 matched controls, 54 RAIR patients had an average age of 57 years (standard deviation [SD] = 13), 56% were male (41% in the control group); the average tumor size was 4 cm (SD = 2.5); tumors were multifocal in 54%, with involved surgical margins in 42%, focal invasion in 79%, and extrathyroidal extension (ETE) in 61%. Sixty-six percent had distant metastases at initial presentation with metastases to the lungs in 85%, bone in 56%, both sites in 43%, brain in 9%, and liver in 4%. There were no statistically significant differences between RAIR and controls in tumor size, focal invasion, ETE, and histology. The RAIR group received a higher cumulative radioactive iodine (RAI) dose and number of therapies compared with the controls (518 mCi vs. 302 mCi, p = 0.002 and 2.2 vs. 1.3 treatments, p = 0.001). Overall, patients >46 years had 4.5 times higher odds ratio (OR) of being RAIR; white race/ethnicity was associated with a reduced OR of RAIR disease (OR 0.33, p = 0.079). Molecular profiling data in the RAIR subgroup indicated that 50% of patients harbored mutations in the RAS/RAF pathway (11/22). Among 19 patients with a more extensive molecular panel, median tumor mutational burden was 5 megabase (range 3-16) and 26% (5/19) exhibited strong PD-L1 positivity. Conclusion: Among patients with metastatic differentiated thyroid carcinomas, patients with RAIR have similar histopathological and clinical characteristics as patients with RAI avid cancer. The risk of having RAIR TC is increased at age ≥46 and reduced in Caucasians.

Risk-oriented concept of treatment for intrathyroid papillary thyroid cancer

Adapting treatment and follow-up according to the risk of recurrence and/or death from thyroid cancer is a relatively recent concept of "personnalized" medicine, developed particularly to avoid overtreatment of low-risk thyroid cancer which represents the majority of thyroid cancers diagnosed in the world today. For low-risk thyroid cancer, this decrease in extent of treatment involves the extent of surgery-total thyroidectomy, lobectomy or no surgery with active surveillance-but also the indications, doses and methods of stimulation when or if administering radioactive iodine (RAI), the indication for suppressive thyroxin therapy and the extent and modalities for follow-up that should be adapted to the risk of recurrence. The aim is to optimize medical resources and quality of life, particularly for low-risk patients whose life expectancy is that of the general population.