Effect of Radioactive Iodine Therapy on Parotid Gland Function

Keratinocyte Growth Factor-1 Protects Radioiodine-Induced Salivary Gland Dysfunction in Mice

BACKGROUND

Most patients with thyroid cancer suffer from salivary gland (SG) dysfunctions after radioiodine (RI) therapy. We investigated the effects of keratinocyte growth factor (KGF)-1 on RI-induced SG dysfunction in an animal model.

METHODS

Six C57BL/6 mice were assigned to each of the following groups: treatment naïve control group, RI group, and RI+KGF-1 group. Body and SG weights, salivary flow rates, salivary lag times and changes in 99mTc pertechnetate uptake and excretion were measured, and histologic changes were noted. Amylase activities and epidermal growth factor (EGF) concentrations in saliva were also measured. In addition, TUNEL assays were performed and apoptosis-related protein expressions were assessed.

RESULTS

RI-induced reductions in salivary flow rates and increases in salivary lag times observed in the RI group were not observed in RI+KGF-1 group. Mice in RI group had higher HIF1a levels than controls, but HIF1a levels in RI+KGF-1 group were similar to those in control group. Furthermore, mice in RI+KGF-1 group had more mucin stained acini and decreased periductal fibrosis than mice in RI group, and tissue remodeling of many salivary epithelial cells (AQP5) and endothelial cells (CD31) were observed in RI+KGF-1 group. Amylase activity and expression in saliva were greater in RI+KGF-1 group than in RI group, and fewer apoptotic cells were observed in RI+KGF-1 group. Furthermore, BCLxl (anti-apoptotic) expression was higher, and Bax (pro-apoptotic) expression was lower in RI+KGF-1 group than in RI group.

CONCLUSIONS

Local delivery of KGF-1 might prevent RI-induced SG damage by reducing apoptosis.

[Anxiety and depression in patients treated for differentiated thyroid microcarcinoma]

Introduction

Le microcarcinome de la thyroïde est un cancer de bon pronostic mais qui peut avoir un retentissement sur la qualité de vie des patients. L'objectif de l'étude est d'évaluer la dépression et l'anxiété chez les patients suivis pour microcarcinome différencié de la thyroïde et de les comparer aux autres stades du cancer.

Méthodes

Étude transversale observationnelle menée entre octobre 2013 et février 2015. L'étude a inclus les patients adultes suivis pour carcinome différencié de la thyroïde. La dépression et l'anxiété ont été évaluées en utilisant deux échelles de qualité de vie, dont la traduction a été validée en arabe: le Hamilton anxiété et Hamilton dépression. Les patients ont été répartis en deux groupes, un groupe microcarcinome de la thyroïde et un groupe non microcarcinome. L'analyse des données faite par le logiciel SPSS. 16.

Résultats

L'étude a concerné 37 patients suivis pour un microcarcinome différencié de la thyroïde, et un groupe de comparaison de 87 patients suivis pour autres stades de cancer différencié de la thyroïde. La qualité de vie des patients dans le groupe avec microcarcinome de la thyroïde était meilleure par rapport aux autres stades de carcinome différencié de la thyroïde. La présence de microcarcinome de la thyroïde était associée significativement à une absence d'anxiété (p = 0,042), une tendance positive a été notée sur le Hamilton dépression (mais p non significatif).

Conclusion

La qualité de vie des patients dans le groupe avec microcarcinome de la thyroïde était meilleure par rapport aux autres stades de carcinome différencié de la thyroïde. Ceci pouvant être expliqué par la non agressivité du traitement (absence de traitement par l'iode, et objectif de TSH plus souple).

Adipose-derived mesenchymal stem cells regenerate radioiodine-induced salivary gland damage in a murine model

After radioiodine (RI) therapy, patients with thyroid cancer frequently suffer from painful salivary gland (SG) swelling, xerostomia, taste alterations, and oral infections. This study was aimed to determine whether adipose-derived mesenchymal stem cells (AdMSCs) might restore RI-induced SG dysfunction in a murine model. Forty -five mice were divided into three groups; a PBS sham group, a RI+ PBS sham group (0.01 mCi/g mouse, orally), and an RI+AdMSCs (1 × 10⁵ cells/150 uL, intraglandular injection on experimental day 28) treated group. At 16 weeks after RI treatment, body weights, SG weight, salivary flow rates (SFRs), and salivary lag times were measured. Morphologic and histologic examinations and immunohistochemistry (IHC) were performed and the activities of amylase and EGF in saliva were also measured. Changes in salivary ^99mTc pertechnetate excretion were followed by SPECT and TUNEL assays were performed. The body and SG weights were similar in the AdMSCs and sham groups. Hematoxylin and eosin staining revealed the AdMSCs group had more mucin-containing acini than the RI group. Furthermore, AdMSCs treatment resulted in tissue remodeling and elevated expressions of epithelial (AQP5) and endothelial (CD31) markers, and increased SFRs. The activities of amylase and EGF were higher in the AdMSCs group than in the RI treated group. ^99mTc pertechnetate excretions were similar in the AdMSCs and sham group. Also, TUNEL positive apoptotic cell numbers were less in the AdMSCs group than in the RI group. Local delivery of AdMSCs might regenerate SG damage induced by RI.

Radioactive Iodine-Induced Hyposalivation: Case Report

Radioactive iodine (¹³¹I) is used in the treatment of differentiated thyroid cancers. Collateral damage to the salivary glands (SGs) can be anticipated. Standard therapeutic doses of ¹³¹I often cause SG obstructive symptomatology and hyposalivation can develop with the higher ¹³¹I doses used for aggressive thyroid malignancies with or without metastases.

Long-term effects of radioiodine treatment on salivary gland function in adult survivors of pediatric differentiated thyroid carcinoma

Pediatric differentiated thyroid cancer (DTC) is a rare disease. Initial treatment of DTC consists of a (near) total thyroidectomy and radioactive iodine (131I) therapy. Previous studies in adults showed that 131I treatment may result in a reduced salivary gland function. Studies regarding salivary gland function in children treated for DTC are sparse. Our aim was to assess long-term effects of 131I treatment on salivary gland function in survivors of pediatric DTC. Methods: In a nationwide cross-sectional study, salivary gland function of patients treated for pediatric DTC between 1970 and 2013 (>5 years after diagnosis, ≥18 years old at time of evaluation) was studied. Salivary gland function was assessed by sialometry, sialochemistry and a xerostomia inventory. Salivary gland dysfunction was defined as unstimulated whole saliva flow ≤0.2mL/min and/or a stimulated whole saliva flow ≤0.7 mL/min. Results: Sixty-five patients (median age at evaluation 33 [IQR, 25-40] years, 86.2% female, median follow-up period 11 [IQR, 6-22] years) underwent 131I treatment. Median cumulative 131I activity was 5.88 [IQR, 2.92-12.95] GBq, 47.7% underwent multiple 131I administrations. Salivary gland dysfunction was present in 30 (47.6%) patients. Levels of amylase and total protein in saliva were reduced. Moderate to severe xerostomia was present in 22 (35.5%) patients. Stimulated salivary secretion was lower and severity of xerostomia complaints higher in patients treated with higher cumulative 131I activity. Conclusion: In survivors of pediatric DTC, clinically significant salivary gland dysfunction was found in 35.5% and was related to the cumulative 131I activity of the treatment.

Clinical Studies of Nonpharmacological Methods to Minimize Salivary Gland Damage after Radioiodine Therapy of Differentiated Thyroid Carcinoma: Systematic Review

Purpose. To systematically review clinical studies examining the effectiveness of nonpharmacological methods to prevent/minimize salivary gland damage due to radioiodine treatment of differentiated thyroid carcinoma (DTC). Methods. Reports on relevant trials were identified by searching the PubMed, CINHAL, Cochrane, and Scopus electronic databases covering the period 01/2000–10/2015. Inclusion/exclusion criteria were prespecified. Search yielded eight studies that were reviewed by four of the present authors. Results. Nonpharmacological methods used in trials may reduce salivary gland damage induced by radioiodine. Sialogogues such as lemon candy, vitamin E, lemon juice, and lemon slice reduced such damage significantly (p < 0.0001, p < 0.05, p < 0.10, and p < 0.05, resp.). Parotid gland massage also reduced the salivary damage significantly (p < 0.001). Additionally, vitamin C had some limited effect (p = 0.37), whereas no effect was present in the case of chewing gum (p = 0.99). Conclusion. The review showed that, among nonpharmacological interventions, sialogogues and parotid gland massage had the greatest impact on reducing salivary damage induced by radioiodine therapy of DTC. However, the studies retrieved were limited in number, sample size, strength of evidence, and generalizability. More randomized controlled trials of these methods with multicenter scope and larger sample sizes will provide more systematic and reliable results allowing more definitive conclusions.

Radioprotective agents for the prevention of side effects induced by radioiodine-131 therapy

Radioiodine 131 (131I) has been used worldwide for the ablation of remnant thyroidal tissue after surgery or as the first-line treatment for Graves’ disease. Although the use of 131I is becoming increasingly prevalent, there is evidence suggesting that this treatment is associated with side effects such as salivary gland dysfunction and an increased risk of leukemia. This article aims to review the potential use of radioprotective agents and the side effects induced by 131I therapy. Several synthetic and natural compounds have been investigated in preclinical and clinical studies. The protective agents reduced the toxicity of 131I, mainly in the salivary glands, and mitigated the genetic damage through different mechanisms. There are limited clinical studies evaluating the use of radioprotective agents in patients undergoing radioiodine therapy. However, lemon candies, lemon juice and sugarless chewing gum have been proposed to be beneficial for minimizing the side effects of radioiodine within the salivary glands.

Radioiodine therapy in benign thyroid diseases: effects, side effects, and factors affecting therapeutic outcome

Radioiodine ((131)I) therapy of benign thyroid diseases was introduced 70 yr ago, and the patients treated since then are probably numbered in the millions. Fifty to 90% of hyperthyroid patients are cured within 1 yr after (131)I therapy. With longer follow-up, permanent hypothyroidism seems inevitable in Graves' disease, whereas this risk is much lower when treating toxic nodular goiter. The side effect causing most concern is the potential induction of ophthalmopathy in predisposed individuals. The response to (131)I therapy is to some extent related to the radiation dose. However, calculation of an exact thyroid dose is error-prone due to imprecise measurement of the (131)I biokinetics, and the importance of internal dosimetric factors, such as the thyroid follicle size, is probably underestimated. Besides these obstacles, several potential confounders interfere with the efficacy of (131)I therapy, and they may even interact mutually and counteract each other. Numerous studies have evaluated the effect of (131)I therapy, but results have been conflicting due to differences in design, sample size, patient selection, and dose calculation. It seems clear that no single factor reliably predicts the outcome from (131)I therapy. The individual radiosensitivity, still poorly defined and impossible to quantify, may be a major determinant of the outcome from (131)I therapy. Above all, the impact of (131)I therapy relies on the iodine-concentrating ability of the thyroid gland. The thyroid (131)I uptake (or retention) can be stimulated in several ways, including dietary iodine restriction and use of lithium. In particular, recombinant human thyrotropin has gained interest because this compound significantly amplifies the effect of (131)I therapy in patients with nontoxic nodular goiter.

Amifostine for salivary glands in high-dose radioactive iodine treated differentiated thyroid cancer

BACKGROUND

Radioactive iodine treatment for differentiated thyroid cancer possibly results in xerostomia. Amifostine has been used to prevent the effects of irradiation to salivary glands. To date, the effects of amifostine on salivary glands in radioactive iodine treated differentiated thyroid cancer remain uncertain.

OBJECTIVES

To assess the effects of amifostine on salivary glands in high-dose radioactive iodine treated differentiated thyroid cancer.

SEARCH STRATEGY

Studies were obtained from computerized searches of MEDLINE, EMBASE, The Cochrane Library and paper collections of conferences held in Chinese.

SELECTION CRITERIA

Randomised controlled clinical trials and quasi-randomised controlled clinical trials comparing the effects of amifostine on salivary glands after radioactive iodine treatment for differentiated thyroid cancer with placebo and a duration of follow up of at least three months.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data.

MAIN RESULTS

Two trials with 130 patients (67 and 63 patients randomised to intervention versus control) were included. Both studies had a low risk of bias. Amifostine versus placebo showed no statistically significant differences in the incidence of xerostomia (130 patients, two studies), the decrease of scintigraphically measured uptake of technetium-99m by salivary or submandibular glands at twelve months (80 patients, one study), and the reduction of blood pressure (130 patients, two studies). Two patients in one study collapsed after initiation of amifostine therapy and had to be treated by withdrawing the infusion and volume substitution. Both patients recovered without sequelae. Meta-analysis was not performed on the function of salivary glands measured by technetium-99m scintigraphy at three months after high dose radioactive iodine treatment due to the highly inconsistent findings across studies (I(2) statistic 99%). None of the included trials investigated death from any cause, morbidity, health-related quality of life or costs.

AUTHORS' CONCLUSIONS

Results from two randomised controlled clinical trials suggest that the amifostine has no significant radioprotective effects on salivary glands in high-dose radioactive iodine treated differentiated thyroid cancer patients. Moreover, no health-related quality of life and other patient-oriented outcomes were evaluated in the two included trials. Randomised controlled clinical trials with low risk of bias investigating patient-oriented outcomes are needed to guide treatment choice.

Candidate protein biodosimeters of human exposure to ionizing radiation

PURPOSE

To conduct a literature review of candidate protein biomarkers for individual radiation biodosimetry of exposure to ionizing radiation.

MATERIALS AND METHODS

Reviewed approximately 300 publications (1973 - April 2006) that reported protein effects in mammalian systems after either in vivo or in vitro radiation exposure.

RESULTS

We found 261 radiation-responsive proteins including 173 human proteins. Most of the studies used high doses of ionizing radiation (>4 Gy) and had no information on dose- or time-responses. The majority of the proteins showed increased amounts or changes in phosphorylation states within 24 h after exposure (range: 1.5- to 10-fold). Of the 47 proteins that are responsive at doses of 1 Gy and below, 6 showed phosphorylation changes at doses below 10 cGy. Proteins were assigned to 9 groups based on consistency of response across species, dose- and time-response information and known role in the radiation damage response.

CONCLUSIONS

ATM (Ataxia telengiectasia mutated), H2AX (histone 2AX), CDKN1A (Cyclin-dependent kinase inhibitor 1A), and TP53 (tumor protein 53) are top candidate radiation protein biomarkers. Furthermore, we recommend a panel of protein biomarkers, each with different dose and time optima, to improve individual radiation biodosimetry for discriminating between low-, moderate-, and high-dose exposures. Our findings have applications for early triage and follow-up medical assessments.

Radioactive iodine and the salivary glands

Radioactive iodine ((131)I) targets the thyroid gland and has been proven to play an effective role in the treatment of differentiated papillary and follicular cancers. Simultaneously, this radioisotope hones in on the salivary glands where it is concentrated and secreted into the saliva. Dose related damage to the salivary parenchyma results from the (131)I irradiation. Salivary gland swelling and pain, usually involving the parotid, can be seen. The symptoms may develop immediately after a therapeutic dose of (131)I and/or months later and progress in intensity with time. In conjunction with the radiation sialadenitis, secondary complications reported include xerostomia, taste alterations, infection, increases in caries, facial nerve involvement, stomatitis, candidiasis, and neoplasia. Prevention of the (131)I sialadenitis may involve the use of sialogogic agents to hasten the transit time of the radioactive iodine through the salivary glands. However, studies are not available to delineate the efficacy of this approach. Recently, amifostine has been advocated to prevent the effects of irradiation. Treatment of the varied complications that may develop encompass numerous approaches and include gland massage, sialogogic agents, duct probing, antibiotics, mouthwashes, good oral hygiene, and adequate hydration.

Dramatic parotid uptake of I-131 on a diagnostic whole-body scan

Radiation sialadenitis is a complication of I-131 therapy for thyroid cancer. They authors report a case of intense uptake by parotid glands in a diagnostic I-131 scan (2 mCi) in whom sialadenitis had developed previously after a 100-mCi dose of I-131. Similar examples of images could not be found in the literature.