Congenital Bilateral Ectopic Parotid Glands: Case Report with Literature Review.

Congenital ectopic bilateral parotid glands are extremely rare, to date only two cases have been reported in the literature. Our patient, a 5-day-old male, presented with bilateral palpable cheek swelling. On imaging, the absence of bilateral parotid glands in parotid space and their ectopic location, anterior to the masseter muscle, was seen. Our case emphasizes ectopic parotids as an important differential among conditions presenting with bilateral cheek swelling in children. We have also compared the findings of previously described cases and their management with our case.

A case of renal sarcoidosis complicated by parotid gland and uterine lesions.

BACKGROUND: Sarcoidosis is a systemic disease that can affect multiple organs. While pulmonary sarcoidosis is most commonly observed, renal sarcoidosis occurs less frequently. We herein report a case of sarcoidosis with an exceptionally rare distribution including renal lesions. CASE PRESENTATION: A 51-year-old Japanese female was referred because of bilateral parotid swelling and renal dysfunction. Computed tomography scan showed the swelling of bilateral kidneys, parotid glands, and uterus. Ga scintigraphy also showed remarkable accumulation in these organs. Renal biopsy and cytological evaluations of parotid gland and uterus were performed and she was diagnosed as sarcoidosis of these organs. Treatment was initiated with prednisolone 40 mg/day and then renal dysfunction subsequently improved. In addition, the swelling of parotid glands and uterus improved and Ga accumulation in each organ had disappeared. CONCLUSION: This is a first case of renal sarcoidosis complicated by parotid glands and uterus lesions. Pathological findings and the reactivity observed in Ga scintigraphy indicated the presence of lesions in these organs.

Chronic Phenotypes Underlying Radiation-Induced Salivary Gland Dysfunction.

Head and neck cancer (HNC) is the sixth most diagnosed cancer, and treatment typically consists of surgical removal of the tumor followed by ionizing radiation (IR). While excellent at controlling tumor growth, IR often damages salivary glands due to their proximity to common tumor sites. Radiation damage to salivary glands results in loss of secretory function, causing severe and chronic reductions in salivary flow. This leads to the patient-reported sensation of dry mouth, termed xerostomia, which significantly reduces quality of life for HNC patients and survivors. The mechanisms underlying salivary gland damage remain elusive, and therefore, treatment options are scarce. Available therapies provide temporary symptom relief, but there is no standard of care for permanent restoration of function. There is a significant gap in understanding the chronic mechanistic responses to radiation as well as treatments that can be given in the months to years following cessation of treatment. HNC cases are steadily rising; particularly, the number of young patients diagnosed with nonfatal human papillomavirus + HNC continues to increase. The growing number of HNC diagnoses and improved prognoses results in more people living with xerostomia, which highlights the mounting need for restorative treatments. Mechanisms underlying chronic damage include decreases in acinar differentiation markers, increases in acinar cell proliferation, immune and inflammatory dysregulation, and metabolic changes including increases in amino acids and reductions in glycolysis and oxidative phosphorylation, fibrosis, and dysregulated neuronal responses. Currently, promising treatment options include adenoviral gene transfers and stem cell therapy. Thus, this review describes in depth known mechanisms contributing to chronic damage and discusses therapeutic advances in treating chronically damaged glands. Understanding the chronic response to radiation offers potential in development of new therapeutics to reverse salivary gland damage and improve the quality of life of HNC survivors.

Towards Automation in Radiotherapy Planning: A Deep Learning Approach for the Delineation of Parotid Glands in Head and Neck Cancer.

The delineation of parotid glands in head and neck (HN) carcinoma is critical to assess radiotherapy (RT) planning. Segmentation processes ensure precise target position and treatment precision, facilitate monitoring of anatomical changes, enable plan adaptation, and enhance overall patient safety. In this context, artificial intelligence (AI) and deep learning (DL) have proven exceedingly effective in precisely outlining tumor tissues and, by extension, the organs at risk. This paper introduces a DL framework using the AttentionUNet neural network for automatic parotid gland segmentation in HN cancer. Extensive evaluation of the model is performed in two public and one private dataset, while segmentation accuracy is compared with other state-of-the-art DL segmentation schemas. To assess replanning necessity during treatment, an additional registration method is implemented on the segmentation output, aligning images of different modalities (Computed Tomography (CT) and Cone Beam CT (CBCT)). AttentionUNet outperforms similar DL methods (Dice Similarity Coefficient: 82.65% ± 1.03, Hausdorff Distance: 6.24 mm ± 2.47), confirming its effectiveness. Moreover, the subsequent registration procedure displays increased similarity, providing insights into the effects of RT procedures for treatment planning adaptations. The implementation of the proposed methods indicates the effectiveness of DL not only for automatic delineation of the anatomical structures, but also for the provision of information for adaptive RT support.

A challenging case of sclerosing polycystic adenoma of the parotid gland: a case report and brief review of the latest updates.

Sclerosing polycystic adenoma (SPA) is a rare neoplastic salivary gland lesion with only about 100 cases reported worldwide so far. The lesion is confused with several malignant and other benign tumors such as apocrine intraductal carcinoma (IC), salivary duct carcinoma (SDC), chronic sclerosing sialadenitis, polycystic dysgenetic disease (PDD), pleomorphic adenoma (PA), acinic cell carcinoma (ACC), and mucoepidermoid carcinoma (MEC). We present a case of SPA for a 23-year-old male patient presenting with a slowly growing parotid mass. Fine needle aspiration (FNA) followed by total excision of the tumor was performed and the picture was consistent with SPA. We discuss the findings of the case and briefly review the literature on SPA.

The impact of submandibular glands protection on xerostomia as monitored by diffusion-weighted imaging in nasopharyngeal carcinoma patients.

PURPOSE: To determine the impact of sparing submandibular glands (SMGs) on alleviating xerostomia and the functional dynamics of the irradiated parotid glands (PGs) and sublingual glands (SLGs) by diffusion-weighted imaging. METHODS: 97 participants underwent 9 rounds of DWI scans before IC (pre-IC), pre-radiation (pre-RT), the midpoint of radiation (mid-RT), the end of radiation (post-RT), 1, 3, 6, 9, 12 (12m-RT) months following radiation. Apparent diffusion coefficient of SMGs (ADCSMG), PGs (ADCPG), and SLGs (ADCSLG), xerostomia questionnaire scores (XQ), and saliva flow rate measures under unstimulated (uSFR) and stimulated condition (sSFR) were documented. RESULTS: ADCPG, ADCSMG, ADCSLG, and XQ showed a rapid increase with a top at 3m-RT followed by regression, whereas uSFR and sSFR had the reverse trend. The change rate of ADC correlated with the dose to PGs, SMGs, and SLGs, as well as uSFR, sSFR, and XQ scores (p < 0.05 for all, except for uSFR with ADCPG (p = 0.063)). Maingroup for ADCPG, uSFR, and sSFR were significant (p values were 0.028, 0.000, 0.000 respectively); ADCPG in SMG sparing group was lower while uSFR, and sSFR were higher than those in the SMG-unsparing group. Simplegroup for ADCSMG, ADCSLG (all p < 0.05 from mid-RT to 12m-RT), and XQ (all p < 0.001 at mid-, 6m-, 9m-, and 12m-RT) were significant; ADCSMG, ADCSLG, and XQ were lower in the SMG-sparing group. CONCLUSIONS: SMG protection has a great impact on the functional retention of PGs and SLGs, resulting in alleviating xerostomia and improving quality of life. TRIAL REGISTRATION: The clinical trial was also registered with the Chinese Clinical Study Registry (registered number: ChiCTR1900024328, Date: July 6, 2019; URL: https://www.chictr.org.cn/showproj.aspx?proj=40726 ).

Chondroma Arising from the Temporomandibular Joint: A Case Report.

Periarticular chondromas are common in the humerus and femur but rarely occur in the temporomandibular joint. We report a case of a chondroma in the anterior part of the ear. One year prior to his visit, a 53-year-old man became aware of swelling in the right cheek region which gradually increased in size. In the anterior part of the right ear, there was a palpable 25 mm tumor, elastic and hard, with poor mobility and without tenderness. A contrast-enhanced computed tomography CT showed a mass lesion with diffuse calcification or ossification in the upper pole of the parotid gland and areas of poor contrast within. A magnetic resonance imaging showed a low-signal mass lesion at the parotid gland with some high signals in both T1 and T2. Fine-needle aspiration cytology did not lead to diagnosis. Using a nerve monitoring system, the tumor was resected with normal tissue of the upper pole of the parotid gland in the same way as for a benign parotid tumor. Distinguishing between pleomorphic adenoma, including diffuse microcalcification of the parotid gland and cartilaginous tumors of the temporomandibular joint, may be sometimes difficult. In such cases, surgical resection may be a beneficial treatment option.

Artificial intelligence to predict outcomes of head and neck radiotherapy.

Head and neck radiotherapy induces important toxicity, and its efficacy and tolerance vary widely across patients. Advancements in radiotherapy delivery techniques, along with the increased quality and frequency of image guidance, offer a unique opportunity to individualize radiotherapy based on imaging biomarkers, with the aim of improving radiation efficacy while reducing its toxicity. Various artificial intelligence models integrating clinical data and radiomics have shown encouraging results for toxicity and cancer control outcomes prediction in head and neck cancer radiotherapy. Clinical implementation of these models could lead to individualized risk-based therapeutic decision making, but the reliability of the current studies is limited. Understanding, validating and expanding these models to larger multi-institutional data sets and testing them in the context of clinical trials is needed to ensure safe clinical implementation. This review summarizes the current state of the art of machine learning models for prediction of head and neck cancer radiotherapy outcomes.

PSMA PET Tumor-to-Salivary Gland Ratio to Predict Response to [177Lu]PSMA Radioligand Therapy: An International Multicenter Retrospective Study.

Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy can improve the outcome of patients with advanced metastatic castration-resistant prostate cancer, but patients do not respond uniformly. We hypothesized that using the salivary glands as a reference organ can enable selective patient stratification. We aimed to establish a PSMA PET tumor-to-salivary gland ratio (PSG score) to predict outcomes after [177Lu]PSMA. Methods: In total, 237 men with metastatic castration-resistant prostate cancer treated with [177Lu]PSMA were included. A quantitative PSG (qPSG) score (SUVmean ratio of whole-body tumor to parotid glands) was semiautomatically calculated on baseline [68Ga]PSMA-11 PET images. Patients were divided into 3 groups: high (qPSG > 1.5), intermediate (qPSG = 0.5-1.5), and low (qPSG < 0.5) scores. Ten readers interpreted the 3-dimensional maximum-intensity-projection baseline [68Ga]PSMA-11 PET images and classified patients into 3 groups based on visual PSG (vPSG) score: high (most of the lesions showed higher uptake than the parotid glands) intermediate (neither low nor high), and low (most of the lesions showed lower uptake than the parotid glands). Outcome data included a more than 50% prostate-specific antigen decline, prostate-specific antigen (PSA) progression-free survival, and overall survival (OS). Results: Of the 237 patients, the numbers in the high, intermediate, and low groups were 56 (23.6%), 163 (68.8%), and 18 (7.6%), respectively, for qPSG score and 106 (44.7%), 96 (40.5%), and 35 (14.8%), respectively, for vPSG score. The interreader reproducibility of the vPSG score was substantial (Fleiss weighted κ, 0.68). The more than 50% prostate-specific antigen decline was better in patients with a higher PSG score (high vs. intermediate vs. low, 69.6% vs. 38.7% vs. 16.7%, respectively, for qPSG [P < 0.001] and 63.2% vs 33.3% vs 16.1%, respectively, for vPSG [P < 0.001]). The median PSA progression-free survival of the high, intermediate, and low groups by qPSG score was 7.2, 4.0, and 1.9 mo (P < 0.001), respectively, by qPSG score and 6.7, 3.8, and 1.9 mo (P < 0.001), respectively, by vPSG score. The median OS of the high, intermediate, and low groups was 15.0, 11.2, and 13.9 mo (P = 0.017), respectively, by qPSG score and 14.3, 9.6, and 12.9 mo (P = 0.018), respectively, by vPSG score. Conclusion: The PSG score was prognostic for PSA response and OS after [177Lu]PSMA. The visual PSG score assessed on 3-dimensional maximum-intensity-projection PET images yielded substantial reproducibility and comparable prognostic value to the quantitative score.

Impact of Dose-Volume Parameters of Parotid Glands on Xerostomia in Patients Irradiated for Head-and-Neck Cancer.

BACKGROUND/AIM: Optimal planning of radiotherapy for head-and-neck cancers should consider the risk of xerostomia. This study investigated the prognostic value of dosevolume parameters of the parotid glands. PATIENTS AND METHODS: Dose-volume parameters were evaluated for xerostomia in 145 patients including D40 (minimum dose to 40% of corresponding parotid volume), D60 (minimum dose to 60%), D80 (minimum dose to 80%), and mean dose of ipsilateral, contralateral, and bilateral parotid glands. RESULTS: Grade ≥2 xerostomia was significantly associated with D40 of ipsilateral and all parameters of bilateral glands; trends were found for all other parameters. Grade ≥3 xerostomia was significantly associated with D80 of bilateral glands; trends were found for other parameters of ipsilateral and bilateral glands. CONCLUSION: Since grade ≥2 xerostomia was associated with all parameters, D40, D60, and D80 did not provide additional information to mean doses. D80 of bilateral glands is a new factor and more predictive than mean dose regarding grade ≥3 xerostomia.

Correlation Between Salivary Microbiome of Parotid Glands and Clinical Features in Primary Sjögren's Syndrome and Non-Sjögren's Sicca Subjects.

Recent studies have demonstrated that the oral microbiome in patients with Sjögren's syndrome (SS) is significantly different from that in healthy individuals. However, the potential role of the oral microbiome in SS pathogenesis has not been determined. In this study, stimulated intraductal saliva samples were collected from the parotid glands (PGs) of 23 SS and nine non-SS subjects through PG lavage and subjected to 16S ribosomal RNA amplicon sequencing. The correlation between the oral microbiome and clinical features, such as biological markers, clinical manifestations, and functional and radiological characteristics was investigated. The salivary microbial composition was examined using bioinformatic analysis to identify potential diagnostic biomarkers for SS. Oral microbial composition was significantly different between the anti-SSA-positive and SSA-negative groups. The microbial diversity in SS subjects was lower than that in non-SS sicca subjects. Furthermore, SS subjects with sialectasis exhibited decreased microbial diversity and Firmicutes abundance. The abundance of Bacteroidetes was positively correlated with the salivary flow rate. Bioinformatics analysis revealed several potential microbial biomarkers for SS at the genus level, such as decreased Lactobacillus abundance or increased Streptococcus abundance. These results suggest that microbiota composition is correlated with the clinical features of SS, especially the ductal structures and salivary flow, and that the oral microbiome is a potential diagnostic biomarker for SS.

Prospective assessment of sparing the parotid ducts via MRI sialography for reducing patient reported xerostomia.

PURPOSE: To assess the impact of prospectively sparing the parotid ducts via MRI sialography on patient reported xerostomia for those receiving definitive radiotherapy (RT) for oropharyngeal squamous cell carcinoma. METHODS AND MATERIALS: Thirty-eight patients with oropharynx cancer to be treated with definitive RT underwent pre-treatment MRI sialograms to localize their parotid ducts. The parotid ducts were maximally spared during treatment planning. Patients reported symptoms (PRO-CTCAE and QLQ-H&N35) were collected at 6 and 12 months post-RT and compared to a historical cohort who underwent conventional parotid gland mean dose sparing. Regression models were generated using parotid and submandibular gland doses with and without incorporating the dose to the parotid ducts to determine the impact of parotid duct dose on patient reported xerostomia. RESULTS: At 6 months post-RT, 12/26 (46%) patients reported ≥moderate xerostomia when undergoing parotid ductal sparing compared to 43/61 (70%) in the historical cohort (p = 0.03). At 12 months post-RT, 8/22 (36%) patients reported ≥moderate xerostomia when undergoing parotid ductal sparing compared to 34/68(50%) in the historical cohort (p = 0.08). Using nested logistic regression models, the mean parotid duct dose was found to significantly relate to patient reported xerostomia severity at 6 months post-RT (p = 0.04) and trended towards statistical significance at 12 months post-RT (p = 0.09). At both 6 and 12 months post-RT, the addition of mean parotid duct dose significantly improved model fit (p < 0.05). CONCLUSIONS: MRI sialography guided parotid duct sparing appears to reduce the rates of patient-reported xerostomia. Further, logistic regression analysis found parotid duct dose to be significantly associated with patient reported xerostomia. A significant improvement in model fit was observed when adding mean parotid duct dose compared to models that only contain mean parotid gland dose and mean contralateral submandibular gland dose.

Multifrequency magnetic resonance elastography-based tomoelastography of the parotid glands-feasibility and reference values.

OBJECTIVES: Accurate radiological differentiation of parotid tumors remains challenging despite recent technical advances in quantitative medical imaging. Multifrequency magnetic resonance elastography (MRE) could provide additional information on viscoelastic properties of normal and abnormal biological tissues. This study investigates the feasibility of MRE of the parotid glands in healthy participants and provides first reference values. METHODS: 20 healthy participants underwent multifrequency MRE of both parotid glands at 3 Tesla. Shear waves at frequencies of 25, 30, 40, and 50 Hz were introduced into the participants' heads through the occiput using pressurized-air actuators. Shear wave speed (SWS) and loss angle of the shear modulus (φ) were reconstructed by tomoelastography post-processing as surrogate parameters for tissue stiffness and viscosity or fluidity. 10 participants underwent repeated MRE to determine test-retest reliability based on intraclass correlation coefficients. RESULTS: All MRE datasets acquired could be included in the analysis. Mean SWS was 0.97 ± 0.13 m/s, and mean φ was 0.59 ± 0.05 rad, each for both sides combined and without notable lateral difference (p = 0.88/0.87). Test-retest reliability was good for SWS (ICC = 0.84 for both sides/ICC = 0.77 for the right side/ICC = 0.79 for the left side) and good to excellent for φ(ICC = 0.94/0.86/0.90). CONCLUSIONS: Multifrequency MRE of the parotid glands is feasible and reliable. This technique, therefore, is a promising method for investigating the viscoelastic properties of salivary gland tumors in future studies.

Primary Extrapulmonary Rifampicin Mono-Resistant Tuberculosis of the Parotid Gland in an Indian Female: The World's First Case.

Tuberculosis at extrapulmonary sites is relatively uncommon. A case of isolated involvement of the salivary gland is even rare and primary rifampicin mono-resistant tuberculosis of the parotid gland is rarest of rare with no such report ever documented in the medical literature. In this case report, the author presents a case of primary extrapulmonary rifampicin mono-resistant tuberculosis of the parotid gland in a 44-year-old Indian female. She presented with complaints of a painless swelling in the right parotid region and underwent a detailed diagnostic work-up including fine needle aspiration cytology, cartridge-based nucleic acid amplification test, computed tomography scan of head and neck, and culture, and was diagnosed with primary extrapulmonary rifampicin mono-resistant tuberculosis of the parotid gland. The patient was initiated on a WHO-recommended regimen per the national guidelines. After nine months of treatment, she had no symptoms and was declared as treatment completed. With no such case ever reported, this case emphasizes the importance of a high degree of suspicion for rare presentations of common diseases like tuberculosis even in the absence of a history, contacts, or other constitutional symptoms.

MR-Guided Adaptive Radiotherapy for Head and Neck Cancer: Prospective Evaluation of Migration and Anatomical Changes of the Major Salivary Glands.

The aim of this study was to quantify anatomical changes of parotids and submandibular glands and evaluate potential dosimetric advantages during weekly adaptive MR-guided radiotherapy (MRgRT) for the definitive treatment of head and neck cancer (HNC). The data and plans of 12 patients treated with bilateral intensity-modulated radiotherapy for HNC using MR-linac, with weekly offline adaptations, were prospectively evaluated. The positional and volumetric changes of the salivary glands were analyzed by manual segmentation in weekly MRI images and the dosimetric impact of these anatomical changes on the adapted treatment plans was assessed. The mean volume change in parotid and submandibular gland volume was -31.9% (p < 0.0001) and -29.7% (p < 0.0001) after five weeks, respectively. The volume change was significantly correlated with the cumulative dose for the respective gland at the time of volume measurement. Inter-parotid distance changed by -5.4% (6.5 mm) on average after five weeks (p = 0.0005). The distance became significantly smaller only in the left-right direction. The inter-submandibular gland distance changed by 0.7 mm (p = 0.38). This study demonstrated significant changes in salivary gland volumes and position following daily MR guidance and weekly plan adaptation. Ongoing clinical trials will provide data on the clinical impact of these changes and novel MR-based adaptation strategies.

Malignant melanoma of parotid glands from a neglected lesion: A case report.

Observing a metastatic malignant melanoma and its primary lesion at the same time is rare. The histopathological detection of any unusual pigmented lesion is critical.

Dynamic Three-Dimensional ADC Changes of Parotid Glands During Radiotherapy Predict the Salivary Secretary Function in Patients With Head and Neck Squamous Carcinoma.

OBJECTIVE: To investigate the changes of three-dimensional apparent diffusion coefficient (3D-ADC) of bilateral parotid glands during radiotherapy for head and neck squamous cell carcinoma (HNSCC) patients and explore the correlations with the radiation dose, volume reduction of parotid gland and the salivary secretary function. MATERIALS AND METHODS: 60 HNSCC were retrospectively collected in Sichuan cancer hospital. The patients were all received diffusion-weighted imaging (DWI) scan at pre-radiation, the 15th radiation, the 25th radiation and completion of radiation. Dynamic 3D-ADC were measured in different lobes of parotid glands (P1: deep lobe of ipsilateral; P2: superficial lobe of ipsilateral; P3: deep lobe of contralateral; P4: superficial lobe of contralateral), and the 3D-ADC of spinal cord were also recorded. Chewing stimulates test, radionuclide scan and RTOG criteria were recorded to evaluate the salivary secretary function. Pearson analysis was used to assess the correlation between 3D-ADC value, radiation dose, volume change, and salivary secretary function. RESULTS: The mean 3D-ADC of parotid glands increased. It began to change at the 15th radiation and the mostly increased in P1. However, there was no change for the maximum and minimum 3D-ADC. The 3D-ADC values of spinal cord changes were almost invisible (ratio ≤ 0.03 ± 0.01). The mean 3D-ADC was negatively correlated with the salivary secretary function (r=-0.72) and volume reduction of different lobes of parotid glands (r1=-0.64; r2=-0.61; r3=-0.57; r4=-0.49), but it was positively correlated with the delivered dose (r1 = 0.73; r2 = 0.69; r3 = 0.65; r4 = 0.78). CONCLUSION: Dynamic 3D-ADC changes might be a new and early indicator to predict and evaluate the secretary function of parotid glands during radiotherapy.

Type B insulin resistance syndrome associated with connective tissue disease and psoriasis.

SUMMARY: Type B insulin resistance syndrome (TBIR) is characterised by the rapid onset of severe insulin resistance due to circulating anti-insulin receptor antibodies (AIRAs). Widespread acanthosis nigricans is normally seen, and co-occurrence with other autoimmune diseases is common. We report a 27-year-old Caucasian man with psoriasis and connective tissue disease who presented with unexplained rapid weight loss, severe acanthosis nigricans, and hyperglycaemia punctuated by fasting hypoglycaemia. Severe insulin resistance was confirmed by hyperinsulinaemic euglycaemic clamping, and immunoprecipitation assay demonstrated AIRAs, confirming TBIR. Treatment with corticosteroids, metformin and hydroxychloroquine allowed withdrawal of insulin therapy, with stabilisation of glycaemia and diminished signs of insulin resistance; however, morning fasting hypoglycaemic episodes persisted. Over three years of follow-up, metabolic control remained satisfactory on a regimen of metformin, hydroxychloroquine and methotrexate; however, psoriatic arthritis developed. This case illustrates TBIR as a rare but severe form of acquired insulin resistance and describes an effective multidisciplinary approach to treatment. LEARNING POINTS: We describe an unusual case of type B insulin resistance syndrome (TBIR) in association with mixed connective tissue disease and psoriasis. Clinical evidence of severe insulin resistance was corroborated by euglycaemic hyperinsulinaemic clamp, and anti-insulin receptor autoantibodies were confirmed by immunoprecipitation assay. Treatment with metformin, hydroxychloroquine and methotrexate ameliorated extreme insulin resistance.

Volume changes during head-and-neck radiotherapy and its impact on the parotid dose - A single-institution observational study.

AIMS: This study aims at assessing the volume changes that occur in the targets (gross tumor volume and planning target volume [PTV]) and the organs at risk in squamous cell carcinoma of the head and neck during radiotherapy and assessing the dose changes that occur as a result of them. SETTINGS AND DESIGN: This was a prospective observational study in a tertiary care center after obtaining the appropriate scientific and ethics committee clearance. SUBJECTS AND METHODS: Forty-five patients diagnosed with squamous cell carcinoma of the head and neck, who were treated with intensity-modulated radiotherapy in the time period from March 2018 to May 2019, were enrolled in the study. A planning computed tomography (CT) scan (CTplan) was done for all patients, followed by scans after 15 fractions (CT15) and after 25 fractions (CT25). The volume changes and the subsequent dose changes were assessed and recorded. STATISTICAL ANALYSIS USED: Data entry was done in MS Excel spreadsheet. The continuous variables were expressed as mean + standard deviation. The comparison of normally distributed continuous variables was done by paired t-test. Data analysis was done by SPSS (Statistical Package for the Social Sciences) version 16.0. P < 0.05 was considered statistically significant. A multivariate linear regression model was constructed to study the correlation between mean dose to the parotid glands and the other variables. All statistical modeling and analysis were done using SAS (Statistical Analysis Software) version 9.4. RESULTS: Of the 45 patients, 25 were male and 20 were female. The majority of the patients had malignancies in the oral cavity (16) and hypopharynx (14). Most of them had Stage III/IV (AJCC v 8) disease (41). There were a 36% decrease in the PTV-high risk (PTV-HR) volume and a 6.05% decrease in the PTV-intermediate risk (PTV-IR) volume CT15. In CT25, the volume decrease in the PTV-HR and the PTV-IR was 47% and 9.06%, respectively. The parotid glands also underwent a reduction in their volume which has been quantified as 21.7% and 20.9% in the ipsilateral and contralateral parotids in CT15 and 36% and 33.6% in CT25, respectively. The D2 (dose received by 2% of the volume) and D98 (dose received by 98% of the volume) of the PTV-IR showed changes of +3.5% and -0.2% in CT15 and + 4.6% and -0.31% in CT25, respectively. The homogeneity index and conformity number of the PTV-IR changes by 0.03 and 0.08 in CT15 and by 0.04 and 0.12 in CT25, respectively. The mean dose to the ipsilateral parotid gland increased by 14% in CT15 and 19% in CT25. The mean dose to the contralateral parotid gland increased by 17% in CT15 and 25% in CT25. CONCLUSION: The dose to the parotid glands increases as a result of the changes that occur during the course of radiation. The changes are significant after 15 fractions of radiation. A replanning at this juncture might be considered to reduce the dose to the parotid glands.

Decreased basal and stimulated salivary parameters by histopathological lesions and secretory dysfunction of parotid and submandibular glands in rats with type 2 diabetes.

Patients with type 2 diabetes mellitus (T2DM) present with dry mouth, polydipsia and taste impairment due to salivary secretion disorder. However, the underlying functional mechanism of T2DM remains unknown. The present study found that T2DM rats had significantly lower salivary flow rate and salivary alpha amylase activity, and attenuated salivary secretion responses to acid stimulation compared with control rats. Histopathological observation found that T2DM rats had inflammatory cell infiltration with increased expressions of IL-6 and TNF-α, oxidative stress, including decreased total superoxide dismutase activity and increased malondialdehyde content, and decreased expressions of ß1 adrenergic receptor, cholinergic receptor, aquaporin-5 and protein kinase A in salivary glands, in particular the parotid gland. These results indicated that parotid gland impairment was more severe compared with submandibular gland impairment. Reduced salivary secretion may be associated with histopathological lesions and decreased regulation in secretory pathways in salivary glands.