Although conventional ultrasound (CUS) allows for clear detection of parotid gland lesions (PGLs), it fails to accurately provide benign-malignant differentiation due to overlapping morphological ...features. Radiomics is capable of processing large-quantity volume of data hidden in CUS image undiscovered by naked eyes. The aim was to explore the potential of CUS-based radiomics score (Rad-score) in distinguishing benign (BPGLs) and malignant PGLs (MPGLs). A consecutive of 281 PGLs (197 in training set and 84 in test set) with definite pathological confirmation was retrospectively enrolled. 1465 radiomics features were extracted from CUS images and Rad-score was constructed by using Least Absolute Shrinkage and Selection Operator (LASSO) algorithm. Different nomogram models, including clinic-radiomics (Clin + Rad-score), CUS-clinic (CUS + Clin) and combined CUS-clinic-radiomics (CUS + Clin + Rad-score), were built using logistic regression. The diagnostic performance of different models were calculated and compared by area under receiver operating curve (AUC) and corresponding sensitivity and specificity. Finally, 26 radiomics features were independent signatures for predicting MPGLs, with MPGLs having higher Rad-scores in both cohorts (both P < 0.05). In the test population, CUS + Clin + Rad-score obtained an excellent diagnostic result, with significantly higher AUC value (AUC = 0.91) when compared to that of CUS + Clin (AUC = 0.84) and Clin + Rad-score (AUC = 0.74), respectively (both P < 0.05). In addition, the sensitivity of this combined model was higher than that of single Rad-score model (100.00% vs. 71.43%, P = 0.031) without compromising the specificity value (82.86% vs. 88.57%, P = 0.334). The calibration curve and decision curve analysis also indicated the clinical effectiveness of the proposed combined nomogram. The combined CUS-clinic-radiomics model may help improve the discrimination of BPGLs from MPGLs.
•For discriminating parotid lesions, the combined nomogram model using clinical information, conventional ultrasound feature and radiomics signature (CUS + Clin + Rad-score) obtained excellent diagnostic performance both in the trainingarea under the receiver operating characteristic curve(AUC) = 0.94 and test cohort (AUC = 0.91).
Surgeons used to be unaware of the facial nerve's position during parotid surgery. Now, with special magnetic resonance imaging (MRI) sequences, it can be located and converted into a 3D model ...displayed on an augmented reality (AR) device for surgeons to study and manipulate. This study explores the accuracy and usefulness of the technique for the treatment of benign and malignant parotid tumours. A total of 20 patients with parotid tumours had 3-Tesla MRI scans, and their anatomical structures were segmented using Slicer software. The structures were imported into a Microsoft HoloLens 2® device, displayed in 3D, and shown to the patient for consent. Intraoperative video recording was used to record the position of the facial nerve in relation to the tumour. The predicted path of the nerve taken from the 3D model was combined with surgical observation and video recording in all cases. The imaging proved to have application in both benign and malignant disease. It also improved the process of informed patient consent. Three-dimensional MRI imaging of the facial nerve within the parotid gland and its display in a 3D model is an innovative technique for parotid surgery. Surgeons can now see the nerve's position and tailor their approach to each patient's tumour, providing personalised care. The technique eliminates the surgeon's blind spot and is a significant advantage in parotid surgery.
Fluoride has become widely used in dentistry because of its effectiveness in caries control. However, evidence indicates that excessive intake interferes with the metabolic processes of different ...tissues. Thus, this study aimed to investigate the effects of long-term exposure to F on the parotid salivary gland of mice, from the analysis of oxidative, proteomic and genotoxic parameters.
The animals received deionized water containing 0, 10 or 50 mg/L of F, as sodium fluoride, for 60 days. After, parotid glands were collected for analysis of oxidative biochemistry, global proteomic profile, genotoxicity assessment and histopathological analyses.
The results revealed that exposure to fluoride interfered in the biochemical homeostasis of the parotid gland, with increased levels of thiobarbituric acid reactive species and reduced glutathione in the exposed groups; as well as promoted alteration of the glandular proteomic profile in these groups, especially in structural proteins and proteins related to oxidative stress. However, genotoxic assessment demonstrated that exposure to fluoride did not interfere with DNA integrity in these concentrations and durations of exposure. Also, it was not observed histopathological alterations in parotid gland.
Thus, our results suggest that long-term exposure to fluoride promoted modulation of the proteomic and biochemical profile in the parotid glands, without inducing damage to the genetic component. These findings reinforce the importance of rationalizing the use of fluorides to maximize their preventative effects while minimizing the environmental risks.
The accessory parotid gland is a normal salivary gland tissue completely separated from the main parotid gland, which is mostly located in the middle of the face. Any tumor originating from the ...parotid gland can occur in the accessory parotid gland. Due to the special location of the disease, the diagnosis and treatment of accessory parotid gland tumor is more difficult and more dangerous than that of the parotid gland tumor. This article reviews the anatomy and physiology, clinical diagnosis and treatment of accessory parotid gland tumors, in order to provide guidance for clinical diagnosis and treatment.
Abstract
Objective
The involvement of salivary glands in primary SS (pSS) can be assessed in different ways: histopathology, salivary flow and ultrasonography. To understand the relative value of ...these different approaches, it is crucial to understand the relationship between them. As we routinely perform these three modalities in the parotid gland for disease evaluation, our aim was to investigate the construct validity between these modalities in one and the same gland.
Methods
Consecutive sicca patients underwent a multidisciplinary diagnostic workup including parotid gland biopsy, collection of parotid gland–specific saliva and parotid gland ultrasonography. Patients who were classified as pSS according to the ACR-EULAR criteria were included. Construct validity was assessed using Spearman’s correlation coefficients.
Results
The 41 included pSS patients completed a full workup within a mean time interval of 2.6 months. Correlations between histopathological features and stimulated parotid salivary flow were fair (ρ = −0.123 for focus score and ρ = −0.259 for percentage of CD45+ infiltrate). Likewise, poor correlations were observed between stimulated parotid salivary flow and parotid ultrasonography (ρ = −0.196). Moderate to good associations were found between the histopathological items focus score and the percentage of CD45+ infiltrate, with parotid US scores (total US score: ρ = 0.510 and ρ = 0.560; highest for homogeneity: ρ = 0.574 and ρ = 0.633).
Conclusion
Although pSS-associated ultrasonographic findings did correlate with histopathological features, the three modalities that evaluate salivary gland involvement assess different (or at best partly related) constructs. Therefore histopathology, salivary flow and ultrasonography are complementary measurements and cannot directly replace each other in the workup of pSS.
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.
Parotid tumors are among the most prevalent tumors in otolaryngology, and malignant parotid tumors are one of the main causes of facial paralysis in patients. Currently, the main diagnostic modality ...for parotid tumors is computed tomography, which relies mainly on the subjective judgment of clinicians and leads to practical problems such as high workloads. Therefore, to assist physicians in solving the preoperative classification problem, a stacked generalization model is proposed for the automated classification of parotid tumor images. A ResNet50 pretrained model is used for feature extraction. The first layer of the adopted stacked generalization model consists of multiple weak learners, and the results of the weak learners are integrated as input data in a meta-classifier in the second layer. The output results of the meta-classifier are the final classification results. The classification accuracy of the stacked generalization model reaches 91%. Comparing the classification results under different classifiers, the stacked generalization model used in this study can identify benign and malignant tumors in the parotid gland effectively, thus relieving physicians of tedious work pressure.
Graphical Abstract
Malignant salivary gland tumors are a relatively rare entity, affecting mostly the parotid gland. They represent 4% of head and neck cancers. They are characterized by the high frequency of local ...recurrences. Given their great diversity, these tumours lead to multiple therapeutic issues. The aim of our study is to describe the epidemioclinical features and therapeutic results of parotid cancers treated in our center.
We report through a retrospective study, 20 cases of parotid gland cancer treated by postoperative radiotherapy (PORT) in our department between 2000 and 2021.
The median age was 45 years 35-56. The sex ratio was 8/12. The main symptom was retro-auricular swelling in 85% of cases. All patients had an MRI of the anatomical region during the pre-therapeutic assessment. Most patients had a locally advanced tumour classified respectively: stage III (50%) IVa (35%) and IVb (15%). Treatment consisted of a total parotidectomy associated with ipsilateral lymph node dissection in all patients. The histological subtypes were mucoepidermoid carcinoma, salivary duct carcinoma and adenoid cystic carcinoma (ACC) in respectively 55%, 25% and 20%. The median size was 3 cm 2-5cm. Histological lymph node invasion (LNI) was present in 70% of cases. surgical margins were positive (R1) in 35% of cases. Lymphovascular emboli (LVEs) were present in 45% of cases.
Radiotherapy was delivered for all patients, using conformational 3D and conventional 2D PORT respectively in 60% and 40% of cases. The median dose of RT was 54 Gy 50-66. The target volumes were the parotid compartment taking into account the pathways of dissemination and anatomical barriers, and the ipsilateral cervical lymph nodes mostly including level Ib, II, III and IV.
After a median follow-up of 48 months (12-252), 6 patients were in a complete remission (30%), 9 patients had a locoregional recurrences (45%) treated with surgery. Five patients had presented a metastatic relapse (25%) after a median period of 12 months, of which 3 patients died.
by analyzing the prognostic factors, a correlation was noted between the poor prognosis of the treated parotid tumor and the ACC histological type (p<0.03), the LNI (p< .005), the LVEs (p<0.04) and the positive surgical margins (p<0.0002).
The main treatment for malignant parotid gland tumors remains surgery. However adjuvant treatment when indicated, is based on PORT. By reviewing scarce data from the literature, Their prognosis depends on several factors such as surgical margins, LNI, LVEs and histological subtype, as it has been demonstrated by our unicenter study.
Aging has pronounced effects on mammalian tissues and cells, but the impacts of aging on salivary gland function are relatively unknown. This study aims to evaluate the effects of aging on ...submandibular gland (SMG) and parotid gland (PG) functions in the male senescence-accelerated mouse. In vivo analysis at the systemic level revealed that salivary secretion induced by pilocarpine, a muscarinic agonist, from the SMG was significantly decreased in aged mice, whereas salivary secretion from the PG was not affected. To evaluate organ-level function, the SMG was perfused with the muscarinic agonists carbachol and calcium ionophore A23187 ex vivo to induce salivary secretion, and decreased saliva production was also observed in the aged SMG. Histological analysis revealed the presence of CD4-positive lymphocytes infiltrating the aged SMG. Furthermore, real-time PCR revealed that the aged SMG exhibited accelerated cell aging, increased levels of the inflammatory cytokine interleukin-6, and decreased mRNA levels of the water channel protein aquaporin-5 (AQP5). In summary, these results demonstrate that SMG function in aged mice was diminished, and that cell senescence, chronic inflammation, and the decreased gene expression of AQP5 are the likely causes of hyposalivation in the SMG of aged mice.
Canalicular adenoma is a rare, benign tumor of primarily salivary gland origin that presents mostly in the upper lip. However, there are only six reports in the English literature detailing ...canalicular adenoma of the parotid gland, none of which discuss discrepancy between preoperative cytology and surgical pathology. In this report, we present a rare case of parotid gland canalicular adenoma where preoperative ultrasound-guided fine-needle aspiration (USFNA) suggested malignancy. The patient was treated with deep lobe parotidectomy due to the FNA results and her multiple comorbidities. However, her tumor may have been treated with observation alone if canalicular adenoma had been suspected prior to surgery.
A 59-year-old female with a history of heart and lung disease presented with a 1.6 cm well defined, enhancing lesion involving the superficial portion of the right parotid gland. This lesion was incidentally noted on CT angiography (CTA) of the neck and chest. The well-defined characteristics of this lesion on CT imaging suggested benign neoplasm. However, USFNA results were suggestive of a malignant parotid lesion. The patient subsequently underwent right deep lobe parotidectomy with facial nerve dissection and superficial musculoaponeurotic system (SMAS) rotational flap reconstruction. Surgical pathology and immunohistochemistry yielded a final diagnosis of benign canalicular adenoma.
USFNA diagnosis of CA is extremely difficult due to its low-grade neoplastic cells mimicking neoplastic cells in other benign and malignant tumors of the head and neck. FNA remains a useful tool for assessing malignancy risk, but the results always have some level of uncertainty and do not provide sufficient detail. Therefore, FNA results should be interpreted in concert with imaging and patients' medical history. Cytopathologists can also report salivary gland FNA results in a more uniform and detailed manner by utilizing the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC).
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