Changes In Parotid Glands Research Articles

Early Changes of Irradiated Parotid Glands Evaluated by T1rho-Weighted Imaging: A Pilot Study

The aim of the study was to confirm the feasibility of T1rho-weighted imaging to evaluate the dynamic changes of parotid glands in patients with nasopharyngeal carcinoma (NPC) undergoing intensity-modulated radiation therapy. Twenty-six NPC patients (19 men; 7 women; mean [SD] age, 48.9 [13.4] years) underwent the following 3 serial T1rho-weighted imaging: within 2 weeks before radiotherapy (RT, pre-RT), 5 weeks after the beginning of RT (mid-RT), and 4 weeks after RT (post-RT). Parotid volumes, T1rho values, mean radiation doses, and xerostomia degrees were recorded. Change rates of parotid T1rho values were correlated with parotid atrophy rates, mean radiation doses, and xerostomia degrees. During RT, parotid volume decreased (atrophy rate, 32.7 [8.1%] at mid-RT and 27.9 [10.0%] at post-RT compared with pre-RT; both P < 0.001) and parotid T1rho values increased (change rate, 25.0 [15.8%] at mid-RT and 30.1 [18.0%] at post-RT compared with pre-RT, both P < 0.001) significantly. The change rate of parotid T1rho value correlated with the atrophy rate significantly at post-RT (r = 0.301, P = 0.047). Intraobserver and interobserver reproducibility of parotid T1rho measurements were excellent (intraclass correlation coefficient, 0.974 and 0.956, respectively). Dynamic changes of radiation-induced parotid damage in NPC patients who underwent intensity-modulated radiation therapy could be noninvasively evaluated by T1rho-weighted imaging.

EP-1822: Monitoring of parotid gland changes in radiotherapy of NPC with parapharyngeal space involvement

EP-1822: Monitoring of parotid gland changes in radiotherapy of NPC with parapharyngeal space involvement

A longitudinal evaluation of early anatomical changes of parotid gland in intensity modulated radiotherapy of nasopharyngeal carcinoma patients with parapharyngeal space involvement.

IntroductionRadiotherapy of nasopharyngeal carcinoma patients with parapharyngeal space (PPS) involvement may deliver high dose to the parotid gland. This study evaluated parotid gland changes during and up to 3 months after radiotherapy.MethodsKilovoltage computed tomography (CT) scans of head and neck region of 39 nasopharyngeal carcinoma patients with PPS involvement were performed at pre‐radiotherapy, 10th, 20th and 30th fractions and 3 months after treatment. The parotid glands were contoured in pre‐radiotherapy planning CT scan and in subsequent scans. Dice similarity coefficient (DSC), percentage volume change and centroid movement between the planning CT and the subsequent CTs were obtained from the contouring software. In addition, the distance between medial and lateral borders of parotid glands from the mid‐line at various time intervals were also measured.ResultsThe ipsilateral parotid gland received a mean dose of about 5 Gy higher than the contralateral side. The mean DSC and parotid volume decreased by more than 30% at 20th fraction and reached the minimum at 30th fraction. Partial recovery was observed at 3 months after treatment. The centroid displacement followed a similar pattern, which moved medially and superiorly by an average of 0.30 cm and 0.18 cm, respectively, at 30th fraction. The changes in ipsilateral gland were slightly greater than the contralateral side.ConclusionsSubstantial volume change and medial movement of parotid gland were observed with slightly greater magnitude in the ipsilateral side. Adaptive radiotherapy was suggested at around 15th to 20th fraction so as to optimise the original dose distribution of the plan.

Influence of Handheld Mobiles on Parotid: A Cohort Study

Introduction: Mobile phones generate heat and radiofrequency radiation. The parotid gland is one potential target, because mobile phones are pressed against the side of the face where the gland is located. Aims and Objectives: To compare the effect of mobile phone radiation on parotid gland volume, systolic velocity, salivary flow rate, and protein concentration between the dominant and the nondominant side of mobile phone usage among heavy mobile phone users. Materials and Methods: Ultrasonography of the superior lobe of parotid was performed bilaterally to measure gland volume. Systolic velocity of the external carotid artery in gland was calculated bilaterally using color Doppler imaging. Saliva flow rate was measured bilaterally with modified Schrimer strip. Carlson-Crittenden device was used to collect 0.5 ml saliva sample from the duct and biuret assay was done to determine the protein concentration. Settings and Design: A cohort study was conducted with 50 undergraduate students of a dental college based on the inclusion and exclusion criteria. Statistical Analysis Used: Pearson correlation test was used to correlate and compare changes in the parameters of parotid gland and analyzed to a significant level of 0.05. Results: The volume, systolic velocity of blood flow of the external carotid artery, the salivary flow rate, and protein concentration of the parotid gland were significantly more by 11.9, 18, 23, and 8%, respectively, on the dominant side than the nondominant side of mobile phone usage. Conclusion: The study emphasized that prolonged mobile phone usage causes biological changes in parotid gland.

Clinical and Sonographic Changes of Parotid Gland in Patients with Type I and Type II Diabetes Mellitus and Its Effect on Physical Properties of Saliva

Clinical and Sonographic Changes of Parotid Gland in Patients with Type I and Type II Diabetes Mellitus and Its Effect on Physical Properties of Saliva

Early evaluation of irradiated parotid glands with intravoxel incoherent motion MR imaging: correlation with dynamic contrast-enhanced MR imaging.

BackgroundRadiation-induced parotid damage is one of the most common complications in patients with nasopharyngeal carcinoma (NPC) undergoing radiotherapy (RT). Intravoxel incoherent motion (IVIM) magnetic resonance (MR) imaging has been reported for evaluating irradiated parotid damage. However, the changes of IVIM perfusion-related parameters in irradiated parotid glands have not been confirmed by conventional perfusion measurements obtained from dynamic contrast-enhanced (DCE) MR imaging. The purposes of this study were to monitor radiation-induced parotid damage using IVIM and DCE MR imaging and to investigate the correlations between changes of these MR parameters.MethodsEighteen NPC patients underwent bilateral parotid T1-weighted, IVIM and DCE MR imaging pre-RT (2 weeks before RT) and post-RT (4 weeks after RT). Parotid volume; IVIM MR parameters, including apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f); and DCE MR parameters, including maximum relative enhancement (MRE), time to peak (TTP), Wash in Rate, and the degree of xerostomia were recorded. Correlations of parotid MR parameters with mean radiation dose, atrophy rate and xerostomia degree, as well as the relationships between IVIM and DCE MR parameters, were investigated.ResultsFrom pre-RT to post-RT, all of the IVIM and DCE MR parameters increased significantly (p < 0.001 for ADC, D, f, MRE, Wash in Rate; p = 0.024 for D*; p = 0.037 for TTP). Change rates of ADC, f and MRE were negatively correlated with atrophy rate significantly (all p < 0.05). Significant correlations were observed between the change rates of D* and MRE (r = 0.371, p = 0.026) and between the change rates of D* and TTP (r = 0.396, p = 0.017). The intra- and interobserver reproducibility of IVIM and DCE MR parameters was good to excellent (intraclass correlation coefficient, 0.633–0.983).ConclusionsEarly radiation-induced changes of parotid glands could be evaluated by IVIM and DCE MR imaging. Certain IVIM and DCE MR parameters were correlated significantly.

Use of T1ρMR imaging in Sjögren's syndrome with normal appearing parotid glands: Initial findings.

To explore the feasibility of parotid spin-lattice relaxation time in the rotating frame (T1ρ) MR imaging in the diagnosis of Sjögren's syndrome (SS) without morphological changes of the parotid glands. The study enrolled 32 consecutive SS patients without morphological changes of parotid glands and 32 age- and gender-matched healthy volunteers who underwent parotid 3.0 Tesla MR imaging, including T1ρ sequences. Follow-up imaging was performed at 3 months. T1 signal intensities and T1ρ values of bilateral parotid glands were compared using paired samples t-test. Parotid T1 signal intensities and T1ρ values were compared using two independent samples t-test. Diagnostic performance of the parotid T1ρ values was evaluated by receiver operating characteristic analysis. The intraclass correlation coefficient (ICC) was calculated to evaluate the reproducibility of parotid T1ρ measurements. There were no significant differences of T1 signal intensities and T1ρ values between bilateral parotid glands in SS patients and healthy volunteers (P = 0.170, 0.886 and 0.942, 0.229). The parotid T1ρ values of SS patients (96.47 ± 15.38 ms) were significantly higher than those of healthy volunteers (84.25 ± 6.11 ms) (P < 0.001), while there were no significant differences of T1 signal intensities between SS patients and healthy volunteers (P = 0.655). With a cutoff value of 88.02 ms, the sensitivity and specificity of the parotid T1ρ value was 75.0% and 100.0% in the diagnosis of SS. The reproducibility of parotid T1ρ measurement was excellent (ICC: 0.934-0.995). Parotid T1ρ MR imaging held a potential role in diagnosing SS without morphological changes of parotid glands. 2 J. Magn. Reson. Imaging 2017;45:1005-1012.

Comparison of functional change in parotid gland after surgical excision of pleomorphic adenoma by two different types of parotidectomy

To compare the functional changes in parotid gland after surgical excision of pleomorphic adenoma by partial superficial parotidectomy (PSP), or conventional superficial parotidectomy (CSP). A prospective study including 117 patients undergoing CSP or PSP was performed. The uptake rate (UR) and excretion fraction (EF) of the parotid gland were measured by salivary gland scintigraphy before the surgery, as well as at months 3, 6, and 12 after the surgery; ΔUR and ΔEF, defined as the UR and EF differences between the contralateral side and the operated side, were also calculated. Either UR or EF of the operated side was lower than that in the contralateral side after surgery (P<.05). ΔEF and ΔUR values at months 6 and 12 were significantly smaller in the PSP group than those in the CSP group. PSP is preferable for preservation of the functions of the parotid gland.

Geometric changes of parotid glands caused by hydration during chemoradiotherapy.

BackgroundPlan adaptation during the course of (chemo)radiotherapy of H&N cancer requires repeat CT scanning to capture anatomy changes such as parotid gland shrinkage. Hydration, applied to prevent nephrotoxicity from cisplatin, could temporarily alter the hydrogen balance and hence the captured anatomy. The aim of this study was to determine geometric changes of parotid glands as function of hydration during chemoradiotherapy compared to a control group treated with radiotherapy only.MethodsThis study included an experimental group (n = 19) receiving chemoradiotherapy, and a control group (n = 19) receiving radiotherapy only. Chemoradiotherapy patients received cisplatin with 9 l of saline solution during hydration in the first, fourth and seventh week. The delineations of the parotid glands on the planning CT scan were automatically propagated to Cone Beam CT scans using deformable image registration. Relative volume and position of the parotid glands were determined at the second chemotherapy cycle (week four) and at fraction 35.ResultsWhen saline solution was administrated, the volume temporarily increased on the first day (7.2 %, p < 0.001), second day (10.8 %, p < 0.001) and third day (7.0 %, p = 0.016). The gland positions shifted lateral, the distance between glands increased on the first day with 1.5 mm (p < 0.001), on the second day 2.2 mm (p < 0.001). At fraction 35, with both groups the mean shrinkage was 24 % ± 11 % (1SD) and the mean medial distance between the parotid glands decreased by 0.47 cm ± 0.27 cm.ConclusionsHydration significantly modulates parotid gland geometry. Unless, in the context of adaptive RT, a repeat CT scan is timed during a chemotherapy cycle, these effects are of minor clinical relevance.

The effect of liquid diet on the parotid gland and the protective role of L-carnitine: immunohistochemical and ultrastructural study.

The moisture content of diet and the dryness of the mouth alter the volume of parotid saliva secreted in rats and it plays an important part in mastication and swallowing. Temporary or permanent liquid diet feeding provides a nutritional regime for patients in certain medical situations. The aim of the present work is to investigate the sequel of liquid diet on parotid gland in rats and the possible protective role of L-carnitine (L-car). Thirty adult male albino rats were divided into three groups (10 per group) - rats were fed on regular pellet diet, Liquid diet group and Liquid diet supplemented with L-car group were received liquid diet. The parotid glands were dissected for histological, immunohistochemical and ultrastructural analysis. By light microscope, liquid fed group showed some areas with degenerated irregularly shaped acini and atrophic acini with vacuolated cytoplasm and pyknotic nuclei. Acinar cells of parotid gland group on liquid diet supplemented with L-car, had normally eosinophilic cytoplasm with few vacuoles in their acinar cells. Periodic acid Schiff (PAS) staining, in liquid fed group showed that the serous acini were weakly stained with PAS that was localised in the apical portion of the cells where the secretory granules lie with lack of staining of the vacuoles. However, moderately stained acinar epithelial cell and fewer vacuoles was seen in group given liquid diet supplemented with L-car. Immunohistochemistry of Caspase 3 showed more apoptotic cells with increased area per cent of Caspase 3 immunoexpression, seen in the acini and more in the ductal epithelium in liquid fed group. It was markedly reduced in the acinar cells in group on liquid diet supplemented with L-car. Electron microscopic study revealed in liquid fed group acini with multiple cytoplasmic vacuoles and reduced secretory granules, degenerated swollen mitochondria and dilated cisternae of endoplasmic reticulum. Degenerated condensed nuclear mass or indented nuclear membrane, nuclei with karyorrhexis and chromatin material leaked in the cytoplasm with rupture of the nuclear membranes were also seen. In parotid gland of liquid fed group supplemented with L-car, acinar cells showed normally distributed secretory granules and few cytoplasmic vacuoles. They showed normal appearance of the nuclei and their cytoplasmic organelles. Liquid diet caused cellular degenerative damages and apoptotic changes in parotid gland and these changes can be prevented by L-car supplementation probably by its antioxidant properties.

Automated Segmentation of the Parotid Gland Based on Atlas Registration and Machine Learning: A Longitudinal MRI Study in Head-and-Neck Radiation Therapy

To develop an automated magnetic resonance imaging (MRI) parotid segmentation method to monitor radiation-induced parotid gland changes in patients after head and neck radiation therapy (RT). The proposed method combines the atlas registration method, which captures the global variation of anatomy, with a machine learning technology, which captures the local statistical features, to automatically segment the parotid glands from the MRIs. The segmentation method consists of 3 major steps. First, an atlas (pre-RT MRI and manually contoured parotid gland mask) is built for each patient. A hybrid deformable image registration is used to map the pre-RT MRI to the post-RT MRI, and the transformation is applied to the pre-RT parotid volume. Second, the kernel support vector machine (SVM) is trained with the subject-specific atlas pair consisting of multiple features (intensity, gradient, and others) from the aligned pre-RT MRI and the transformed parotid volume. Third, the well-trained kernel SVM is used to differentiate the parotid from surrounding tissues in the post-RT MRIs by statistically matching multiple texture features. A longitudinal study of 15 patients undergoing head and neck RT was conducted: baseline MRI was acquired prior to RT, and the post-RT MRIs were acquired at 3-, 6-, and 12-month follow-up examinations. The resulting segmentations were compared with the physicians' manual contours. Successful parotid segmentation was achieved for all 15 patients (42 post-RT MRIs). The average percentage of volume differences between the automated segmentations and those of the physicians' manual contours were 7.98% for the left parotid and 8.12% for the right parotid. The average volume overlap was 91.1% ± 1.6% for the left parotid and 90.5% ± 2.4% for the right parotid. The parotid gland volume reduction at follow-up was 25% at 3 months, 27% at 6 months, and 16% at 12 months. We have validated our automated parotid segmentation algorithm in a longitudinal study. This segmentation method may be useful in future studies to address radiation-induced xerostomia in head and neck radiation therapy.

Ultrasonic Nakagami‐parameter characterization of parotid‐gland injury following head‐and‐neck radiotherapy: A feasibility study of late toxicity

The study aims to investigate whether Nakagami parameters--estimated from the statistical distribution of the backscattered ultrasound radio-frequency (RF) signals--could provide a means for quantitative characterization of parotid-gland injury resulting from head-and-neck radiotherapy. A preliminary clinical study was conducted with 12 postradiotherapy patients and 12 healthy volunteers. Each participant underwent one ultrasound study in which ultrasound scans were performed in the longitudinal, i.e., vertical orientation on the bilateral parotids. For the 12 patients, the mean radiation dose to the parotid glands was 37.7 ± 9.5 Gy, and the mean follow-up time was 16.3 ± 4.8 months. All enrolled patients experienced grade 1 or 2 late salivary-gland toxicity (RTOG/EORTC morbidity scale). The normal parotid glands served as the control group. The Nakagami-scaling and Nakagami-shape parameters were computed from the RF data to quantify radiation-induced parotid-gland changes. Significant differences in Nakagami parameters were observed between the normal and postradiotherapy parotid glands. Compared with the control group, the Nakagami-scaling parameter of the postradiotherapy group decreased by 25.8% (p < 0.001), and the Nakagami-shape parameter decreased by 31.3% (p < 0.001). The area under the receiver operating characteristic curve was 0.85 for the Nakagami-scaling parameter and was 0.95 for the Nakagami-shape parameter, which further demonstrated the diagnostic efficiency of the Nakagami parameters. Nakagami parameters could be used to quantitatively measure parotid-gland injury following head-and-neck radiotherapy. Moreover, the clinical feasibility was demonstrated and this study provides meaningful preliminary data for future clinical investigation.

Anatomic and Dosimetric Changes of Parotid Glands During the Course of IMRT for Nasopharyngeal Cancer Patients: Definitive Management of Head-and-Neck Squamous Cell Carcinoma

Anatomic and Dosimetric Changes of Parotid Glands During the Course of IMRT for Nasopharyngeal Cancer Patients: Definitive Management of Head-and-Neck Squamous Cell Carcinoma

PO-0896: Dynamic characterization of structural and anatomical changes of parotid glands during IMRT using texture analysis

PO-0896: Dynamic characterization of structural and anatomical changes of parotid glands during IMRT using texture analysis

Effects of menopause and diabetes on the rat parotid glands: A histopathological and stereological study

Background: The menopause is a physiological process that occurs and diabetes is a metabolic disease that has an increased incidence in advancing age in women. Aims & Objective: The purpose of the study to examine the effect of menopause and/or diabetes that causes pathophysiological status on parotid gland. Materials and Methods: Sprague-dawley 24 adult female rats (12 week old) were randomly, six rats in each group, divided into four groups; non-diabetic healthy (control), Diabetic (DM) group, Ovariectomized (OVX) group, Post Ovariectomy-Diabetes Induced (DM+OVX) group, respectively. To evaluate the results histopathological, histochemical and stereological analyses were performed. Results: Degenerative acini and duct cells with increased cytoplasmic lipid accumulation (vacuolization) in DM groups, polymorph nuclear infiltrations in OVX groups and extensive swollen nucleus with karyorrhexis and increased cytoplasmic lipid accumulation in serous acinus cells in DM+OVX group were detected. Furthermore the changes in the amount and character of secretion especially DM and DM+OVX groups and hypertrophic changes in the acinus epithelium in DM and/or the OVX groups were distinguished. Conclusion: The results revealed the effects of diabetes and ovariectomy on the cellular changes and pathophysiological processes of these changes in parotid glands. These findings may highlight to other pathophysiological processes of the role of the salivary glands associated with the pathogenesis due to diabetes and menopause. Additionally, correlated molecular mechanism of pathophysiological processes of DM and/or OVX on parotid gland, suggested further investigation.

Texture analysis for the assessment of structural changes in parotid glands induced by radiotherapy

Background and purposeDuring radiotherapy (RT) for head-and-neck cancer, parotid glands undergo significant anatomic, functional and structural changes which could characterize pre-clinical signs of an increased risk of xerostomia. Texture analysis is proposed to assess structural changes of parotids induced by RT, and to investigate whether early variations of textural parameters (such as mean intensity and fractal dimension) can predict parotid shrinkage at the end of treatment. Material and methodsTextural parameters and volumes of 42 parotids from 21 patients treated with intensity-modulated RT for nasopharyngeal cancer were extracted from CT images. To individuate which parameters changed during RT, a Wilcoxon signed-rank test between textural indices (first and second RT week; first and last RT week) was performed. Discriminant analysis was applied to variations of these parameters in the first two weeks of RT to assess their power in predicting parotid shrinkage at the end of RT. ResultsA significant decrease in mean intensity (1.7HU and 3.8HU after the second and last weeks, respectively) and fractal dimension (0.016 and 0.021) was found. Discriminant analysis, based on volume and fractal dimension, was able to predict the final parotid shrinkage (accuracy of 71.4%). ConclusionTextural features could be used in combination with volume to characterize structural modifications on parotid glands and to predict parotid shrinkage at the end of RT.

OC-0350: Geometric changes of parotid glands caused by pre- and posthydration during chemoradiotherapy

OC-0350: Geometric changes of parotid glands caused by pre- and posthydration during chemoradiotherapy

Cone-beam computed tomography dose monitoring during intensity-modulated radiotherapy in head and neck cancer: parotid glands

To evaluate the dosimetric changes of parotid glands (PG) during a course of intensity-modulated radiotherapy (IMRT) in head and neck (H&N) cancer patients. Ten patients with H&N cancer treated by IMRT were analyzed. The original treatment plan (CT(plan)) was transferred to cone-beam computed tomography (CBCT) acquired at the 15th and 20th treatment day (CBCT(plan) I and II, respectively). The PG mean dose (D(mean)), the dose to 50 % of the volume, and the percent of volume receiving 30 and 50 Gy were measured by the dose volume histogram. 30 IMRT plans were evaluated (3 plans/patient). All dosimetric end points increased significantly for both PG only when CT(plan) was compared to CBCT(plan) I. The D(mean) increased significantly only for ipsilateral PG (p = 0.02) at week 3. During a course of IMRT, CBCT is a feasible method to check the PG dosimetric variations. Perhaps, the 3rd week of radiotherapy could be considered as the time-check-point.

Parotid gland volumetric changes during intensity-modulated radiotherapy in head and neck cancer

To evaluate volumetric changes of parotid glands (PGs) during intensity-modulated radiotherapy (IMRT) in head and neck cancer patients. During IMRT all patients underwent kilovolt cone-beam CT (CBCT) scans to verify the set-up positioning in a protocol study. On each CBCT scan, the PGs were retrospectively contoured and evaluated with a dose-volume histogram. From February to June 2011, 10 patients were enrolled. 140 CBCT scans were registered (280 PGs): for each patient, a median of 14 CBCT scans were performed (range 14-16). At the start of radiation, the average volume for ipsilateral PGs (iPGs) was 18.77 ml (range 12.9-31.2 ml), whereas for contralateral PGs (cPGs) it was 16.63 ml (range 8.3-28.7 ml). At the last CBCT scan, the average volume loss was 43.5% and 44.0% for the iPG and cPG, respectively. When we analysed the percentage of volume loss, we observed that the volume decreased by linear regression (r(2)=0.92 for iPG; r(2)=0.91 for cPG), with an average volume loss rate of 1.5% per day for both PGs. During the third week of treatment the volume of both PGs reduced by 24-30%. Our data show that, during IMRT, the shrinkage of PGs should be taken into account. A replan could be indicated in the third week of radiotherapy.

A case of Sjögren's syndrome presenting as trigeminal nerve palsy

We herein report the case of a female with Sjogren's syndrome (SS) complicated with trigeminal nerve palsy. Although her sicca symptoms had been unnoticed, head magnetic resonance imaging (MRI) for detecting brain abnormalities revealed parotid gland changes associated with SS. SS should be considerd as a possible cause of trigeminal nerve disturbances. In addition, parotid gland changes related to SS should be aware in examination of cranial nerve disturbances with MRI.