Prediction of risk for symptomatic sialadenitis by post-therapeutic dual 131I scintigraphy in patients with differentiated thyroid cancer

Objective

The aim of this study is to predict the risk of symptomatic sialadenitis after ¹³¹I therapy using the early (third day post-therapy) and delayed (fifth or sixth day post-therapy) post-therapeutic ¹³¹I scintigraphy images in patients with differentiated thyroid cancer (DTC).

Methods

Included in the study were 112 patients with DTC who underwent early and delayed ¹³¹I scans after ¹³¹I treatment. All patients had normal salivary gland function on salivary scintigraphy performed in the week before the ¹³¹I treatment. Scintigraphy images were visually analyzed and the salivary gland-to-background uptake ratio (SUR) and percent change of the SUR between early and delayed scans were calculated. Calculation of effective half-life and absorbed dose in the salivary glands was performed based on the MIRD schema.

Results

Of 112 patients, symptomatic sialadenitis was diagnosed in 46 patients (41 %). Of these 46 patients, 83 % (38 patients) had persistent ¹³¹I uptake in the salivary glands on both early and delayed scans. Among 55 patients with persistent ¹³¹I uptake in the salivary glands, 69 % experienced symptomatic sialadenitis, while only 14 % of the other 57 patients experienced symptomatic sialadenitis (p < 0.0001). On the early ¹³¹I scintigraphy, SURs of bilateral parotid glands on early scan in patients with symptomatic sialadenitis were significantly higher than in other patients (p = 0.001 for right and p = 0.004 for left). Further, patients with symptomatic sialadenitis had a higher decreasing rate of the SUR and shorter effective half-life of ¹³¹I in bilateral parotid glands than other patients. Using visual analysis and SURs of right and left parotid glands on early ¹³¹I scan as parameters, the sensitivities for predicting symptomatic sialadenitis were 83, 80, and 93 %, respectively. The mean values of effective half-life and absorbed dose in the parotid and submandibular glands were 20.8 ± 6.3 h and 2.7 ± 0.8 Gy, and 22.1 ± 7.9 h and 2.8 ± 1.1 Gy, respectively.

Conclusions

Symptomatic sialadenitis can be predicted by post-therapeutic ¹³¹I scintigraphy with high sensitivity. Post-therapeutic ¹³¹I scintigraphy could provide effective information on the risk of symptomatic sialadenitis in DTC patients who underwent ¹³¹I treatment.     

Prostaglandins as biochemical markers of radiation injury to the salivary glands after iodine-131 therapy?

Because salivary glands, as well as thyroid tissue, are able to concentrate radioiodine, the treatment of thyroid diseases with iodine-131 may have secondary effects on salivary gland function which seriously impair the quality of life. Such effects include sialoadenitis and xerostomia. Salivary secretion is stimulated by prosta- glandins (PGs). In this study we evaluate whether ¹³¹I therapy influences the levels of PGs in saliva. Patients who had previously received ¹³¹I for treatment of hyperthyroidism or differentiated thyroid cancer and healthy volunteers were studied. Levels of PGs [6-oxo-PGF_1α, bicyclo-PGEm, thromboxane B₂ (TXB₂), PGF_2α] in unstimulated saliva were measured using enzyme immunoassay. Significantly lower levels of 6-oxo-PGF_1α, bicyclo-PGEm and PGF_2α and higher levels of TXB₂ were found in the group of patients in comparison with the controls. Differences between patients and controls were more pronounced in smokers. This study demonstrates that salivary gland uptake of ¹³¹I significantly affects PG levels in saliva. Received 25 September and in revised form 24 November 1997     

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.     

The influence of saliva flow stimulation on the absorbed radiation dose to the salivary glands during radioiodine therapy of thyroid cancer using 124I PET(/CT) imaging

Purpose

A serious side effect of high-activity radioiodine therapy in the treatment of differentiated thyroid cancer is radiogenic salivary gland damage. This damage may be diminished by lemon-juice-induced saliva flow immediately after ¹³¹I administration. The aim of this study was to assess the effect of chewing lemon slices on the absorbed (radiation) doses to the salivary glands.

Methods

Ten patients received (pretherapy) ¹²⁴I PET(/CT) dosimetry before their first radioiodine therapy. The patients underwent a series of six PET scans at 0.5, 1, 2, 4, 48 and ≥96 h and one PET/CT scan at 24 h after administration of 27 MBq ¹²⁴I. Blood samples were also collected at about 2, 4, 24, 48, and 96 h. Contrary to the standard radioiodine therapy protocol, the patients were not stimulated with lemon juice. Specifically, the patients chewed no lemon slices during the pretherapy procedure and neither ate food nor drank fluids until after completion of the last PET scan on the first day. Organ absorbed doses per administered ¹³¹I activity (ODpAs) as well as gland and blood uptake curves were determined and compared with published data from a control patient group, i.e. stimulated per the standard radioiodine therapy protocol. The calculations for both groups used the same methodology.

Results

A within-group comparison showed that the mean ODpA for the submandibular glands was not significantly different from that for the parotid glands. An intergroup comparison showed that the mean ODpA in the nonstimulation group averaged over both gland types was reduced by 28% compared to the mean ODpA in the stimulation group (p=0.01). Within each gland type, the mean ODpA reductions in the nonstimulation group were statistically significant for the parotid glands (p=0.03) but not for the submandibular glands (p=0.23). The observed ODpAs were higher in the stimulation group because of increased initial gland uptake rather than group differences in blood kinetics.

Conclusion

The ¹²⁴I PET(/CT) salivary gland dosimetry indicated that lemon juice stimulation shortly after ¹³¹I administration in radioiodine therapy increases the absorbed doses to the salivary glands.     

Scintigraphic evaluation of salivary gland dysfunction in patients with thyroid cancer after radioiodine treatment

PURPOSE: Sialadenitis is a well-recognized adverse effect of high-dose radioactive iodine treatment. This study was undertaken to determine whether Tc-99m pertechnetate salivary gland scintigraphy may be used for objective assessment of salivary gland function in patients with thyroid cancer treated with I-131. PATIENTS AND METHODS: The study group consisted of 71 patients (16 men, 55 women) with a mean age of 44 years (range, 16 to 73 years). Twenty-six (37%) patients were not given any radioiodine, and 18, 16, and 11 patients received doses of 100, 150, or 200 mCi (or higher), respectively. Parotid and submandibular glands were evaluated based on a four-grade scoring system. Correlation between the type of surgery, administered dose, time since therapy, subjective symptoms, and findings of salivary gland scintigraphy were evaluated. RESULTS: Subjective symptoms were questioned in 39 of the 45 patients who received radioactive iodine treatment. Fifty-four percent (21 of 39) of the patients reported xerostomia, of whom 86% (18 of 21) showed salivary gland dysfunction. Objective salivary gland dysfunction was observed in 69% (31 of 45) of patients. In 81% of the patients, the parotid glands were affected; in 13% of the patients, the submandibular glands were affected; and in 6%, both were affected ( < 0.000001). The frequency of salivary gland dysfunction showed a dose dependence to cumulative activity ( = 0.007). A greater complication rate was observed in patients with total thyroidectomy compared with subtotal surgery, although the correlation was not significant ( = 0.625). CONCLUSIONS: Parenchymal damage to the salivary glands induced by radioactive iodine treatment can be evaluated by salivary gland scintigraphy. The impairment is worse in the parotid glands and increases with the total dose.     

The sodium-iodine symporter and the proton-pump inhibitors in - related to the side effects of- the treatment of thyroid cancer with iodine-131

Iodine-131 ((131)I) administered to patients for imaging or treatment, concentrates in the gastrointestinal tract, including the salivary glands, stomach and bowel. In Nuclear Medicine practice this biological property of iodine causes side effects when the therapeutic dose of (131)I is large. This occurs during the treatment of patients with differentiated thyroid carcinoma (DTC). During this clinical application, the dose of (131)I is higher than 3.7 GBq. Side effects of this treatment with respect to the stomach, include gastritis as an inflammatory reaction to radiation, anorexia due to gastric atrophy and rarely megaloblastic anemia due to lack of the endogenous factor. Side effects can also include xerostomia. We have recently tried to prevent gastric side effects by prescribing proton pump inhibitors (PPI) for patients with DTC prior to treatment with (131)I. PPI block the excretion of hydrochloric acid from the gastric mucosa and are utilized for the prevention and treatment of gastritis, gastric ulcers and gastroesophageal reflux. Whole body scans before or after the administration of PPI, showed that PPI do not interfere with the biologic distribution of (131)I. These findings were not surprising. Recent studies in animals and humans have shown that the accumulation and concentration of iodine by the thyroid gland is the result of the selective action of sodium iodine symporter (Na+I+symporter, NIS). Furthermore, it was shown that the accumulation and concentration of (131)I in the parietal cells of the gastric mucosa, the ductal cells of the salivary glands and the alveolar epithelial cells of the mammary glands, is analogous to the biologic action of NIS in the thyroid cells. The gastric mucosa accumulates iodine from the capillaries via the extracellular/extravascular space and finally excretes it into the lumen of the stomach, from where it is passively transferred into the bowel, where it is partially reabsorbed to once again enter its metabolic cycle. On the contrary, as it is now known, the PPI have an entirely different metabolic action, which is unrelated to that of the NIS, although both mechanisms coexist in the parietal cells of the gastric mucosa. Thus, during the application of (131)I for imaging or for the treatment of DTC patients, except for the short period of time immediately after the oral administration, when the radionuclide passes through the stomach, the concentration of (131)I in the gastrointestinal tract is due to its active accumulation and excretion by the gastric mucosa. PPI act only on the hydrochloric acid secretion not affecting the biologic properties of iodine.     

Significance of Salivary Gland Radioiodine Retention on Post-ablation 131I Scintigraphy as a Predictor of Salivary Gland Dysfunction in Patients with Differentiated Thyroid Carcinoma

Purpose

We investigated whether ¹³¹I whole-body scintigraphy could predict functional changes in salivary glands after radioiodine therapy.

Methods

We evaluated 90 patients who received initial high-dose (≥3.7 GBq) radioiodine therapy after total thyroidectomy. All patients underwent diagnostic (DWS) and post-ablation (TWS) ¹³¹I whole-body scintigraphy. Visual assessment of salivary radioiodine retention on DWS and TWS was used to divide the patients into two types of groups: a DWS+ or DWS- group and a TWS+ or TWS- group. Salivary gland scintigraphy was also performed before DWS and at the first follow-up visit. Peak uptake and %washout were calculated in ROIs of each gland. Functional changes (Δuptake or Δwashout) of salivary glands after radioiodine therapy were compared between the two groups.

Results

Both peak uptake and the %washout of the parotid glands were significantly lower after radioiodine therapy (all p values <0.001), whereas only the %washout were significantly reduced in the submandibular glands (all p values <0.05). For the parotid glands, the TWS+ group showed larger Δuptake and Δwashout after radioiodine therapy than did the TWS- group (all p values <0.01). In contrast, the Δuptake and Δwashout of the submandibular glands did not significantly differ between the TWS+ and TWS- groups (all p values >0.05). Likewise, no differences in Δuptake or Δwashout were apparent between the DWS+ and DWS- groups in either the parotid or submandibular glands (all p values >0.05).

Conclusion

Salivary gland radioiodine retention on post-ablation ¹³¹I scintigraphy is a good predictor of functional impairment of the parotid glands after high-dose radioiodine therapy.     

Pre-therapeutic 124I PET(/CT) dosimetry confirms low average absorbed doses per administered 131I activity to the salivary glands in radioiodine therapy of differentiated thyroid cancer

Purpose  

Salivary gland impairment following high activity radioiodine therapy of differentiated thyroid cancer (DTC) is a severe side effect. Dosimetric calculations using planar gamma camera scintigraphy (GCS) with ¹³¹I and ultrasonography (US) provided evidence that the average organ dose per administered ¹³¹I activity (ODpA) is too low to account for observed radiation damages to the salivary glands. The objective of this work was to re-estimate the ODpA using ¹²⁴I PET(/CT) as a more reliable approach than ¹³¹I GCS/US.     

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.     

Salivary gland accumulation of meta-[131I]iodobenzylguanidine

Intense uptake of m-[131I] iodobenzylguanidine (I-131 MIBG ) has been observed in the salivary glands of patients undergoing scintigraphy for the location of suspected pheochromocytomas. This uptake of radioactivity was not due to free I-131 derived from the I-131 MIBG but rather to uptake of I-131 MIBG by sympathetic neuronal elements in the salivary glands. In keeping with this, administration of tricyclic antidepressants reversibly blocked salivary uptake of I-131 MIBG . Furthermore, I-131 MIBG uptake was markedly diminished by the ipsilateral salivary glands in a patient with Horner's syndrome, and was bilaterally diminished in a patient with severe idiopathic sympathetic autonomic neuropathy. The salivary gland uptake of I-131 MIBG may provide a means for the study of sympathetic innervation of these organs, and thus for the study of generalized disorders of autonomic innervation.     

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

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

Long-term follow-up studies on Iodine-131 treatment of hyperthyroid graves’ disease based on the measurement of thyroid volume by ultrasonography

In the present series of studies, the long-term (four year) effect of 80 Gy of¹³¹I treatment was evaluated in patients with hyperthyroid Graves’ disease whose thyroid volumes have been accurately estimated with a high resolution ultrasound scanner. One year after¹³¹I treatment, 23.1 % (3 out of 13 patients) remained hyperthyroid, 69.2% (9 out of 13) became euthyroid, and 7.7% (1 out of 13) were in a hypothyroid state. Since three patients in a hyperthyroid state one year after treatment were subsequently treated with either antithyroid drugs or additional¹³¹I treatment, the remaining ten patients (9 euthyroid and 1 hypothyroid patients) have been followed up for three more years. Two patients developed a hypothyroid state three years after treatment and one patient four years after treatment. Overall, 60% (6 out of 10 patients) were in a euthyroid state and 40% (4 out of 10) in a hypothyroid state, four years after 80 Gy¹³¹I treatment. There was no significant difference between eu- and hypothyroid groups in the sex ratio, age, radiation dose, therapeutic dose, thyroid gland volume, 24-hr¹³¹I uptake, the effective half-life of¹³¹I in the thyroid or the duration of hyperthyroidism. In our preliminary studies, the incidence of late hypothyroidism in our¹³¹I treatment is similar to those previously reported. These suggest that uncertain factor(s), such as inhomogeneity of iodine distribution in the thyroid, unequal sensitivity of the thyroid cells to the radiation, and/or persistent destructive effects of the autoimmune process may influence the long-term effect of¹³¹I treatment of Graves’ disease.     

综合干预措施下评估首次131I清甲治疗对分化型甲状腺癌患者唾液腺的慢性损伤

目的研究探讨分化型甲状腺癌（DTC）患者在采取综合干预措施后首次131I清甲治疗对唾液腺功能的慢性损伤情况。方法选取2016年8月至2017年9月在攀枝花市中心医院核医学科首次行131I（4200.24±604.21）MBq清甲治疗的DTC患者52例,所有患者均在131I清甲治疗后立即采取综合干预措施（饮食护理、心理护理、物理护理、口腔卫生护理、健康宣教及药物治疗等）,并分别于131I清甲前和治疗后6个月行99TcmO₄-唾液腺动态显像,计算其摄取峰值和排泌分数,所得数据采用自身配对t检验分析,同时联合口干评分法评估唾液腺功能的损伤情况。结果（1）左侧腮腺摄取峰值在131I清甲前为45.157±19.421,治疗后6个月为52.600±21.716,差异有统计学意义（t=2.470,P=0.018）。（2）右侧腮腺、双侧颌下腺的摄取峰值及双侧腮腺、双侧颌下腺的排泌分数之间的差异均无统计学意义（t=0.784、0.524、0.514、0.362、0.731、0.596、0.507,均P>0.05）。（3）对52例患者行问卷调查和口干评分法分析,其中,50例（96.2%）患者无口干症状,仅有2例（3.8%）出现轻度口干症状。结论（1）首次131I清甲治疗可引起DTC患者唾液腺功能受损,损伤主要以单侧腮腺摄取功能为主,呈非对称性损伤。双侧颌下腺的摄取和排泌功能则未受到明显影响。（2）症状上,在综合干预保护措施下,绝大部分患者在接受首次131I清甲治疗后6个月无明显口干情况,生活质量无明显影响。     

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.     

Posttherapeutic <Superscript>131</Superscript>I SPECT-CT offers high diagnostic accuracy when the findings on conventional planar imaging are inconclusive and allows a tailored patient treatment regimen

Purpose  The purpose of this prospective study was to determine the diagnostic impact and influence on patient treatment of posttherapeutic ¹³¹I SPECT-CT when the findings on planar posttherapeutic whole-body scintigraphy (ptWBS) were inconclusive. Materials and methods  A total of 53 SPECT-CT scans were performed in 41 patients with thyroid cancer after high-dose ¹³¹I therapy (2.944 to 7.526 GBq ¹³¹I) because of diagnostic uncertainty on ptWBS. Physiological uptake in the salivary glands, gastric mucosa, gut, nasal mucosa, urinary tract and liver were considered to be normal. Any other foci of increased ¹³¹I uptake, except iodine uptake clearly located in the thyroid bed, were considered to be abnormal. The data were evaluated on a lesion and a patient basis. Results  Regarding neck lesions, SPECT-CT provided a diagnostic impact in 26/90 lesions (28.9%) and confirmed the diagnosis in 64/90 lesions (71.1%). On a patient basis, SPECT-CT changed N status in 12/33 patients (36.4%), provided a diagnostic impact in 21/33 patients (63.6%) and led to a treatment change in 8/33 patients (24.2%). Regarding lesions distant from the neck, SPECT-CT confirmed the diagnosis in 62/71 lesions (87.3%) and had a diagnostic impact in 9/71 lesions (12.7%). On a patient basis, SPECT-CT changed M status in 4/19 patients (21.1%), had a diagnostic impact in 14/19 patients (73.7%) and led to a treatment change in 2/19 patients (10.5%). Considering all patients, SPECT-CT led to a treatment change in 10/41 patients (24.4%). Conclusion  Integrated SPECT-CT is a useful tool, especially in cases of diagnostic uncertainty and helps to individualize patient management.     

131I致分化型甲状腺癌患者唾液腺辐射损伤及其防治的研究进展

131I治疗分化型甲状腺癌（DTC）的技术成熟、效果显著,是DTC患者术后综合治疗的主要方法之一,目前已被广泛应用于临床。但其造成的唾液腺辐射损伤（口干、腮腺肿痛、味觉改变等）会对DTC患者的生活质量造成一定影响。近年来,各种唾液腺辐射损伤防护剂层出不穷,但其确切疗效较为局限,且治疗方案尚未规范统一。笔者就DTC患者术后行131I治疗对唾液腺的辐射损伤及其防治的研究进展进行综述。     

MR imaging of labial glands

BACKGROUND AND PURPOSE: The labial salivary gland is a site of occurrence of tumors and cysts, and it serves as the biopsy site for the diagnosis of Sjögren syndrome. However, its imaging features have not been well understood. Here we attempted to depict the labial gland by high-resolution MR imaging.MATERIALS AND METHODS: The labial glands from 89 patients without Sjögren syndrome, 14 patients with Sjögren syndrome, and 3 patients with tumor or cyst of the lips were imaged by using a 1.5T MR imager with a 47- or 110-mm surface coil.RESULTS: The upper and lower labial glands consisted of 1–3 layers of gland clusters, each of which had high signal intensity on T1-weighted and fat-suppressed T2-weighted images and was readily enhanced after gadolinium injection. The posterior parts of the glands were thicker than the anterior parts. The gland areas in the lower lips (186 ± 64 mm² in women and 192 ± 68 mm² in men) were greater than those in the upper lips (140 ± 46 mm² in women and 162 ± 66 mm² in men). We did not find any significant age-related changes or sex differences in the gland area. The labial gland areas were smaller in the patients with Sjögren syndrome than in patients without Sjögren syndrome, though the difference was significant only in the upper lips (104 ± 53 mm²).CONCLUSION: This is the first report describing imaging features of the labial salivary glands. High-resolution MR imaging can readily delineate the labial glands.

The minor salivary glands are distributed throughout the anterior two thirds of the tongue, palatal mucosa, buccal mucosa, and lips. The total number of minor salivary glands is estimated to fall into the range of 600-1000.¹ Collectively, the minor salivary glands produce 6%–10% of the whole saliva.² Saliva, particularly the mucins and secretary immunoglobulin A in minor salivary gland secretions, is considered to play an important role in the protection of the oral mucosa and teeth.¹ Although the saliva secretion from the minor salivary glands is small in quantity compared with the whole saliva secretion, the broader distributions of the minor salivary glands are advantageous for the protection of the oral cavity against pathogens.Recently, MR imaging features of the major salivary glands in patients with Sjögren syndrome have been extensively described on the basis of studies using conventional T1- and T2-weighted imaging^3,4 and diffusion-weighted imaging.⁵ The labial salivary glands have been widely used for the diagnosis of Sjögren syndrome.⁶ In addition, the minor salivary glands, including the labial glands, are the sites for the occurrence of benign and malignant tumors and cysts. However, to our knowledge, the imaging features of healthy or diseased minor salivary glands have not been described.The paucity of publications of the imaging features of the minor salivary glands may be mainly due to their small size as well as underestimation of the role of the minor salivary glands in maintenance of the oral environment. In the present study, we attempted to delineate the MR imaging features of the healthy labial salivary glands by using small-sized surface coils.     

Iodine trapping and organification in patients with chronic renal failure

In vitro thyroid function tests were studied in 30 patients on regular hemodialysis. In addition, 8 patients (one not yet dialyzed) underwent perchlorate discharge testing and the salivary to plasma ratio of¹³¹I was measured to identify defects in iodine uptake or organification. When compared with 35 healthy controls, uremic patients had lower total T4 (5.8±0.4 vs 8.6±0.3 μg/100 ml) and total T3 (81±6 vs 124±5 ng/100 ml) but T3RU was higher in dialysis patients (35.5±0.9 vs 28±0.5%,P<0.01). The TSH levels were not different from those of controls. The RAI uptake 1 h after perchlorate was significantly higher than the control valve (0.6±0.14 vs 0.06±0.04,P<0.05). Similarly, the salivary to plasma ratio of¹³¹I was higher in patients with chronic renal failure (70±10:1 vs 40±4:1). It is concluded that there is altered iodine trapping in CRF patients but iodine organification appears to be normal.     

甲状腺癌术后^131I治疗后唾液腺功能的半定量评价

目的应用放射性核素显像对甲状腺癌术后首次和多次^131I治疗后唾液腺功能的变化进行观察和半定量评价。方法收集56例DTC术后^131I治疗后6个月行唾液腺显像患者,其中21例行首次^131I治疗前及治疗后6个月唾液腺显像。通过计算获得摄取功能参数：4min摄取比值（UR4）和15min摄取比值（UR15）;排泄功能参数：最大排泄量（MS）和酸刺激后腺体计数下降到最低所需的时间（Tmin）。21例首次^131I治疗前后定量参数行配对t检验。将所有唾液腺显像按治疗前、第1次治疗后6个月、第2次治疗后6个月、≥3次治疗后6个月分为4组,各组功能参数进行单因素方差分析和Kruskal-Wallis秩和检验,并对^131I治疗次数与功能参数行Spearman等级相关分析。结果21例首次^131I治疗后6个月,左、右侧腮腺UR15分别下降16％和14％（t值为2．188和3．322,P均〈0．05）,腮腺其余参数及颌下腺所有参数与治疗前比较差异均无统计学意义（t值为-0．952～2．039,P均〉0．05）。按治疗次数分组比较,4组腮腺UR4、UR15、MS如下：左侧分别为1．76±0．29,2．60±0．38,（72．8±24．2）％;1．55±0．34,2．15±0．51,（64．4±21．6）％;1．55±0．40,2．02±0．68,（57．2±34．2）％;1．45±0．33,1．69±0．46,（30．6±36．9）％;右侧分别为：1．81±0．33,2．57±0．51,（69．1±18．5）％;1．61±0．38,2．19±0．59,（64．2±25．0）％;1．60±0．42,2．00±0．62,（53．2±41．7）％;1．48±0．38,1．63±0．29,（26．1±45．9）％;组间差异有统计学意义（左右侧UR4、UR15的F值分别为7．018,13．393和3．112,10．194,左右侧MSH=12．240,26．569,P均〈0．05）。Tmin 4组间差异无统计学意义（左右侧H=2．077,3．019,P均〉0．05）。组间两两比较：^131I治疗1次及2次患者与对照组比较仅UR15减低有统计学意义（P均〈0．05）,但^131I治疗1次与2次组间所有参数差异均无统计学意义（P均〉0．05）,^131I治疗≥3次组双侧腮腺UR4、UR15及MS均显著下降（P均〈0．05）。双侧腮腺UR4、UR15、MS与^131I治疗次数呈负相关,r值为-0．296～-0．566,P均〈0．05。颌下腺各项参数各组间差异均无统计学意义（F值为0．275—1．159,P均〉0．05）。结论DTC术后首次大剂量^131I治疗后6个月仅腮腺摄取功能轻度减低,第2次治疗后腮腺功能损害无明显进展,≥3次^131I治疗后腮腺摄取及排泄均明显受损;颌下腺经多次^131I治疗后仍无明显功能受损。     

125I Seed implant brachytherapy for the treatment of parotid gland cancers in children and adolescents

Background and purpose

There is a lack of optimal treatment strategies for managing salivary gland cancers in children and adolescents. This study is aimed at assessing the effect of ¹²⁵I seed implantation for the treatment of parotid cancers in children and adolescents.

Patients and methods

A total of 12 patients younger than 16 years with parotid gland malignant tumors underwent ¹²⁵I seed implant brachytherapy between October 2003 and November 2008. All patients were assessed after treatment and at the local tumor control appointments. Facial nerve function, maxillofacial development, and radioactive side-effects were assessed.

Results

The follow-up period ranged from 41–104 months. One patient with T4b died of pulmonary metastasis. The other patients were alive during the follow-up period. There were no serious radiation-related complications. The treatment did not affect facial nerve function and dentofacial growth in any of the children.

Conclusion

For parotid gland cancers in children, ¹²⁵I seed implant brachytherapy may be an acceptable treatment without serious complications and with satisfactory short-term effects.