Effect of reserpine on salivary gland radioiodine uptake in thyroid cancer

Nine patients with thyroid cancer were treated with reserpine in an attempt to reduce radiation exposure to the salivary glands from 100-150 mCi doses of I-131 therapy to thyroid remnants or metastases. Three control patients were not treated with reserpine but did receive 100-150 mCi of I-131. Parotid/background ratios of activity after radioablative doses of I-131 in patients not treated with reserpine were significantly higher than the patients treated with reserpine, and this was also true seven days after the radioablative dose. Combined therapy with reserpine, chewing gum, lemon candies, and hydration is suggested for the prevention of sialadenitis and xerostomia due to large doses of radioiodine.     

Does lemon candy decrease salivary gland damage after radioiodine therapy for thyroid cancer?

Salivary gland dysfunction is one of the common side effects of high-dose radioiodine therapy for thyroid cancer. The purpose of this study was to determine whether an early start of sucking lemon candy decreases salivary gland injury after radioiodine therapy. METHODS: The incidence of the side effects of radioiodine therapy on the salivary glands was prospectively and longitudinally investigated in 2 groups of patients with postsurgical differentiated thyroid cancer with varying regimens for sucking lemon candy. From August 1999 to October 2000, 116 consecutive patients were asked to suck 1 or 2 lemon candies every 2-3 h in the daytime of the first 5 d after radioiodine therapy (group A). Lemon candy sucking was started within 1 h after radioiodine ingestion. From November 2000 to June 2002, 139 consecutive patients (group B) were asked to suck lemon candies in a manner similar to that of group A. In the group B, lemon candies were withheld until 24 h after the ingestion of radioiodine. Patients with salivary gland disorders, diabetes, collagen tissue diseases, or a previous history of radioiodine therapy or external irradiation to the neck were excluded. Thus, 105 patients in group A and 125 patients in group B were available for analysis. There were no statistical differences in the mean age (55.2 y vs. 58.5 y), average levels of serum free thyroxine (l-3,5,3',5'-tetraiodothyronine) (0.40 ng/dL vs. 0.47 ng/dL), and the mean dose of (131)I administered (3.96 GBq vs. 3.87 GBq) between the 2 groups. The onset of salivary side effects was monitored during hospital admission and regular follow-up on the basis of interviews with patients, a visual analog scale, and salivary gland scintigraphy using (99m)Tc-pertechnetate. When a patient showed a persistent (>4 mo) dry mouth associated with a nonfunctioning pattern on salivary gland scintigraphy, a diagnosis of xerostomia was established. RESULTS: The incidences of sialoadenitis, hypogeusia or taste loss, and dry mouth with or without repeated sialadenitis in group A versus group B were 63.8% versus 36.8% (P < 0.001), 39.0% versus 25.6% (P < 0.01), and 23.8% versus 11.2% (P < 0.005), respectively. Permanent xerostomia occurred in 15 patients in group A (14.3%) and 7 patients in group B (5.6%) (P < 0.05). In both groups, bilateral involvement of the parotid gland was the most frequently seen and was followed by bilateral involvement of the submandibular gland. CONCLUSION: An early start of sucking lemon candy may induce a significant increase in salivary gland damage. Lemon candy should not be given until 24 h after radioiodine therapy.     

Relationship between cumulative radiation dose and salivary gland uptake associated with radioiodine therapy of thyroid cancer

AIM: To estimate the individual absorbed dose to the parotid and submandibular salivary glands in radioiodine therapy and its dependence from the previous cumulative therapy. METHODS: Fifty-five patients with differentiated thyroid carcinoma after thyroidectomy received 1-21 GBq (131)I using single activities of 1-6 GBq. The patients were stratified according to the cumulative activities into low-activity (1-2 GBq), middle-activity (3-7 GBq), and high-activity groups (9-21 GBq). The time-activity curves over the respective salivary glands were derived from multiple static calibrated images measured for each patient up to 48 h after ingestion of the radioiodine therapy capsule with a gamma camera. Manually drawn regions of interests were used to determine the background activities and the activities arising from the salivary glands. The gland volumes were determined by ultrasonography using appropriate volume models. RESULTS: The median absorbed dose per administered activity of each single parotid and submandibular gland was about 0.15 Gy.GBq (range, 0.1-0.3 Gy.GBq(-1)) and 0.48 Gy.GBq(-1) (range, 0.2-1.2 Gy.GBq(-1)), respectively. The maximum uptake of both gland types was significantly lower for the high-activity than for the low-activity groups and correlated with the mean cumulative administered activity of the activity groups. CONCLUSION: The iodine uptake of salivary glands is significantly reduced, whereas the absorbed dose per administered (131)I activity was not significantly decreased during the course of therapy. Comparing the well-known dose-effect relationships in external radiation therapy, the absorbed dose per administered (131)I activity is too low to induce comparable radiation damage, suggesting an inhomogeneous distribution of (131)I in human salivary glands.     

Semi-quantitative assessment of salivary gland function in patients with differentiated thyroid carcinoma after radioiodine-131 treatment

Sialadenitis and xerostomia are well-known side effects of high-dose radioactive iodine ((131)Iota) treatment in patients with differentiated thyroid carcinoma (DTC). This study was undertaken to determine salivary gland function semi-quantitatively in patients with DTC given (131)I for the treatment of the thyroid remnant and/or metastases. Thirty-six patients, 11 males and 25 females, mean age 53.5 years, range 22-73 years, were studied. Scintigraphy of the salivary glands was performed with (99m)Tc-pertechnetate and the salivary excretion fraction (SEF) of the parotid and the submandibular glands was calculated as a measure of their function. Measurements were performed before (131)I treatment as a baseline study, and three weeks and three months later. The patients were clinically evaluated by a standardized subjective questionnaire. Results were as follows: Mean SEF at three weeks and three months after (131)I treatment was reduced as compared to baseline measurements. The total mean baseline measurements, those of three weeks and those of three months later were: 54.9%, 47.2% and 46% respectively; P<0.05 for both measurements (Table 1). The SEF decrease of the parotid glands was greater than that of the submandibular glands (P<0.05 as compared for both salivary glands before and three weeks and three months after (131)I treatment). This confirmed the higher radiosensitivity of the parotid glands as compared to the submandibular glands. In 12 patients (33%) there was no significant decrease of SEF in the salivary glands after (131)I treatment. The relation between the decrease of SEF after three weeks and after three months and the dose of (131)I administered, was for the right and left submandibular glands significant (P=0.016 and P=0.002), while for the parotid glands it was insignificant (P=0.22 and P=0.27 respectively) (Table 4). Reduction of SEF in the parotid glands three months after (131)I treatment was greater than after three weeks. This difference, as regards the submandibular glands, was not significant. Our results show that high dose (131)I treatment in DTC patients induces a significant effect on salivary gland function, which is dose-related in the submandibular glands, and more prominent in the parotid glands.     

分化型甲状腺癌患者131I治疗后唾液腺功能变化的诊疗进展

唾液腺功能受损是头颈部肿瘤患者放化疗中常见的不良反应,其对患者的生活质量及治疗效果产生严重影响,唾液腺功能受损发生率随着头颈部疾病发病率的增高而增高,亟需明确的防治手段。目前已有大量国内外研究结果揭示了唾液腺功能放射性损伤的部分机理并提供了一些防治措施予以临床参考。笔者重点综述由131I治疗引起的唾液腺功能损伤的机制、症状、诊断及防治措施。     

分化型甲状腺癌患者131I治疗后唾液腺损伤的相关因素分析

目的 探讨分化型甲状腺癌（DTC）患者131I 治疗后唾液腺损伤的危险因素。 方法 回顾性分析2019年1月至2022年7月于山西医科大学第一医院行131I治疗的107例DTC患者的临床资料,其中男性35例、女性72例,年龄（42.8±1.0）岁。比较唾液腺损伤患者与唾液腺正常患者年龄、身体质量指数、收缩压、舒张压、原发肿瘤的组织病理学分型及分期、是否有淋巴结转移、是否并发糖尿病、131I治疗前促甲状腺素（TSH）水平、停用左甲状腺素钠片（L-T4）时间、131I治疗剂量、131I全身显像（WBS）等临床资料的差异。符合正态分布的计量资料的组间比较采用单因素方差分析（ANOVA）,计数资料的组间比较采用χ2检验,期望频数<5时采用Fisher确切概率法。通过单因素分析和多因素Logistic回归分析明确唾液腺损伤的相关因素。 结果 107例DTC患者中,37例患者发生唾液腺损伤,唾液腺损伤的发生率为34.6%。单因素分析结果显示,唾液腺损伤患者的年龄、收缩压大于唾液腺正常患者[（45.84±2.10）岁 对（41.11±0.97）岁,（127.59±3.10） mm Hg对（119.86±1.84） mm Hg],唾液腺损伤患者131I治疗前TSH水平低于唾液腺正常患者[（99.82±8.46） mIU/L对（122.59±4.03） mIU/L],且差异有统计学意义（F=5.457、5.210、6.288,均P<0.05）。多因素Logistic回归分析结果显示,年龄、131I治疗前TSH水平、收缩压是唾液腺功能损伤的非独立危险因素（OR=1.017、0.989、1.023,均P>0.05）。 结论 年龄较大、131I治疗前TSH水平较低及收缩压较高是DTC患者行131I 治疗出现唾液腺损伤的相关因素。     

Visualization of nasolacrimal drainage system after radioiodine therapy in patients with thyroid cancer

The objective of this study was to report three cases with an accumulation of ¹³¹I in the nasolacrimal duct after radioiodine therapy for papillary thyroid cancer. A whole-body scan was taken 3 days after the administration of 3.7 GBq of ¹³¹I. Single-photon emission computed tomography (SPECT)/CT images were added when the location of a focal tracer uptake was undetermined on whole-body scans. In case 1, a 62-year-old woman complained of epiphora of the left eye after nine radioiodine therapies with a cumulative dose of 31.08 GBq. The left nasolacrimal duct was visualized at her tenth treatment with ¹³¹I. In case 2, a series of three radioiodine therapies had been given to a 73-year-old woman with a cumulative dose of 11.1 GBq. The accumulation of ¹³¹I was noted in the left nasolacrimal duct at her fourth treatment. She complained of epiphora of the left eye. In case 3, bilateral nasolacrimal ducts were visualized at the second radioiodine therapy in a 75-year-old woman. The patient had received 3.7 GBq of ¹³¹I at the first therapy. She did not complain of epiphora. It is possible that radiation from ¹³¹I that is secreted in tears and/or actively accumulated in the nasolacrimal duct may induce nasolacrimal duct obstruction. ¹³¹I in tears would be responsible for the visualization of nasolacrimal duct in the first two cases. ¹³¹I actively accumulated in the nasolacrimal duct might have been visualized in the third case. In summary, ¹³¹I is excreted in tears and is actively accumulated in the nasolacrimal duct. Obstruction of the lacrimal drainage system could occur after high-dose radioiodine therapy.     

The effect of high-dose radioiodine treatment on lacrimal gland function in patients with differentiated thyroid carcinoma

PURPOSE: There are a limited number of case reports confirming the radioiodine (I-131) presence in tears and only a few case reports of lacrimal gland dysfunction after I-131 therapy. This study was designed to clarify whether lacrimal gland function can be affected by I-131 therapy. MATERIALS AND METHODS: We studied 100 eyes of 50 patients who had received high doses of I-131 for treatment of differentiated thyroid carcinoma and 100 eyes of 50 age- and sex-matched control individuals without a history of interfering conditions. The exposed group was studied at least 3 months after their last I-131 therapy. Dry eye symptoms and Schirmer test values (wetting level in millimeters per 5 minutes) of an exposed group were compared with those of an unexposed group. RESULTS: Fifty-one percent of the exposed eyes and 50% of the unexposed ones revealed at least 1 of the dry eye symptoms. There was no significant difference in symptoms between 2 groups, except for burning sensation and eye redness, which were significantly higher in the exposed eyes. A lower Schirmer test value was noted in the exposed group, 14.5 +/- 10.8 mm, when compared with that in controls, 18.2 +/- 11.0 mm (P = 0.016), and the relative risk of an abnormal Schirmer test in exposed cases to control group was 1.78 +/- 0.62. Correlation coefficient analysis showed no significant relationship between Schirmer test values and cumulative doses of administered I-131. CONCLUSIONS: Reduction in the tear secretion from lacrimal glands is seen after high-dose I-131 therapy; however, their symptoms are no greater than an unexposed population.     

Enhanced radioiodine uptake in a patient with poorly differentiated papillary thyroid cancer after treatment with rosiglitazone

The effect of pretreatment with the peroxisome proliferator-activated receptor (PPAR) agonist, rosiglitazone, on radioiodine uptake and serum thyroglobulin levels in a patient with radioiodine-resistant papillary thyroid cancer is described. Treatment with rosiglitazone resulted in enhanced radioiodine uptake in areas of presumed metastatic disease in the neck that were previously only faintly seen, and serum thyroglobulin fell from a pretreatment level of 41 ng/mL to less than 2 ng/mL.     

Symptomatic late-onset sialadenitis after radioiodine therapy in thyroid cancer

Objective

The aim of this study was to document the subjective and objective findings of symptomatic late-onset sialadenitis after radioiodine therapy in patients with differentiated thyroid cancer.

Methods

Subjective symptoms related to sialadenitis and Tc-99m pertechnetate salivary gland scintigram findings were assessed in 118 patients (26 males, 92 females) both before and during the late phase (mean 338 days) after the administration of radioiodine.

Results

Twelve of the 118 patients (10.2 %) complained of symptomatic sialadenitis in the late phase without symptoms during the early phase (within 7 days of radioiodine administration). Significant associations were found between subjective symptoms and visual scintigram findings during the late phase (p = 0.023). Furthermore, uptake and excretion by both parotid glands were significantly affected by radioiodine therapy.

Conclusions

Symptomatic late-onset sialadenitis occurred at an incidence of 10.2 %, and salivary gland function was affected in both parotids in most patients.     

The long-term hazards of the treatment of thyroid cancer with radioiodine

Two-hundred and fifty-eight patients treated with high-activity 131I for thyroid cancer and on prolonged follow-up have been reviewed to determine long-term hazards and their relation to the radiation dose received. The expectation of life of those dying from causes other than cancer was slightly reduced in the female patients. A small, significant excess of deaths from cancer of the bladder and from leukaemia was found which, assuming that these were due to radiation, gave inferred risk-rates respectively of 0.4 and 4.9 deaths per 10(4) PYG (patient-year-grays) to the bladder wall and red marrow. Of 31 younger patients (eight male, 23 female), four of the marriages have been infertile. The fertile marriages produced a total of 44 live births. Considerable gonad irradiation (estimated 0.8-2.7 Gy) was compatible with apparently normal fertility. Despite the high level of irradiation of the salivary glands, no malignancies and only one adenoma was found. Impaired pulmonary function occurred in only one of the patients who had diffuse bilateral metastases. In this patient, tumour in the lung was persistent throughout, so that radiation was probably not alone responsible.     

Scintigraphic evaluation and dynamic studies with thallium-201 in thyroid lesions with suspected cancer

Scintigraphic studies of the thyroid with thallium-201 chloride were performed in 46 patients in whom the final diagnosis was established by histology. In dynamic studies of 36 patients, sequential imaging was performed the first 40 min after injection. A single exponential, Cexp(-t), was fitted to each of the curves generated from apparently pathological and from normal regions in each patient, as determined by earlier conventional scintigrams. To minimize the effects of normal individual variations, the relation between pathological (p) and normal (n) regions in the same patient was emphasized and quantified by two parameters, namely the extrapolated zero-time intercept (C _p /C _n ) and the time development of the ratio of couting rates/unit area in the two regions. The turnover appears to be somewhat slower for pathological tissue than for normal tisue. Although this difference was significant on the 5% level for both cancer and adenoma as a group, only the relative disappearance rate resolved cancer from adenoma and from goiter on the same level. All but one of the differentiated cancers had a increased uptake.