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Physics in Medicine and Biology Nov 2020During radiation therapy (RT) of head and neck (HN) cancer, the shape and volume of the parotid glands (PG) may change significantly, resulting in clinically relevant...
During radiation therapy (RT) of head and neck (HN) cancer, the shape and volume of the parotid glands (PG) may change significantly, resulting in clinically relevant deviations of delivered dose from the planning dose. Early and accurate longitudinal prediction of PG anatomical changes during the RT can be valuable to inform decisions on plan adaptation. We developed a deep neural network for longitudinal predictions using the displacement fields (DFs) between the planning computed tomography (pCT) and weekly cone beam computed tomography (CBCT). Sixty-three HN patients treated with volumetric modulated arc were retrospectively studied. We calculated DFs between pCT and week 1-3 CBCT by B-spline and Demon deformable image registration (DIR). The resultant DFs were subsequently used as input to our novel network to predict the week 4 to 6 DFs for generating predicted weekly PG contours and weekly dose distributions. For evaluation, we measured dice similarity (DICE), and the uncertainty of accumulated dose. Moreover, we compared the detection accuracies of candidates for adaptive radiotherapy (ART) when the trigger criteria were mean dose difference more than 10%, 7.5%, and 5%, respectively. The DICE of ipsilateral/contralateral PG at week 4 to 6 using the prediction model trained with B-spline were 0.81 [Formula: see text] 0.07/0.81 [Formula: see text] 0.04 (week 4), 0.79 [Formula: see text] 0.06/0.81 [Formula: see text] 0.05 (week 5) and 0.78 [Formula: see text] 0.06/0.82 [Formula: see text] (week 6). The DICE with the Demons model were 0.78 [Formula: see text] 0.08/0.82 [Formula: see text] 0.03 (week 4), 0.77 [Formula: see text] 0.07/0.82 [Formula: see text] 0.04 (week 5) and 0.75 [Formula: see text] 0.07/0.82 [Formula: see text] 0.02 (week 6). The dose volume histogram (DVH) analysis with the predicted accumulated dose showed the feasibility of predicting dose uncertainty due to the PG anatomical changes. The AUC of ART candidate detection with our predictive model was over 0.90. In conclusion, the proposed network was able to predict future anatomical changes and dose uncertainty of PGs with clinically acceptable accuracy, and hence can be readily integrated into the ART workflow.
Topics: Cone-Beam Computed Tomography; Head and Neck Neoplasms; Humans; Parotid Gland; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Intensity-Modulated; Retrospective Studies
PubMed: 33007769
DOI: 10.1088/1361-6560/abbdb8 -
Journal of Ultrasound Sep 2021Parotid gland oncocytoma (PGO) is a rare benign epithelial tumor that usually occurs in the elderly population. The most common clinical presentation is a painless,... (Review)
Review
Parotid gland oncocytoma (PGO) is a rare benign epithelial tumor that usually occurs in the elderly population. The most common clinical presentation is a painless, slow-growing, non-tender, lobulated, and mobile mass. Histologically, it is composed of monotonous sheets of epithelial cells (oncocytes) with a central scar. The cross-sectional appearance is not specific, and it overlaps with other parotid lesions. On ultrasound (US), oncocytoma appears as an ovoid, well-defined, homogeneous, and hypoechoic lesion. Cystic and hemorrhagic areas as well as intralesional fat may be observed. Doppler analysis shows intratumoral vessels, sometimes with a spoke-wheel pattern. The peak systolic flow is high (up to 100 cm/sec). Furthermore, oncocytoma is avid of FDG on a PET scan, as well as a malignant tumor. Thus, a combined clinical, imaging, and pathologic assessment is essential to establish the most accurate diagnosis and plan the best treatment. US, combined with Doppler techniques, can play an important role in suggesting the diagnosis and confirming it through percutaneous sampling. The purpose of this review is to show the imaging findings in PGO, with special emphasis on the US appearance.
Topics: Adenoma, Oxyphilic; Aged; Cross-Sectional Studies; Humans; Neoplasms, Glandular and Epithelial; Parotid Gland; Parotid Neoplasms; Ultrasonography
PubMed: 32710434
DOI: 10.1007/s40477-020-00511-5 -
Indian Journal of Pathology &... 2023Neoplastic lipomatous lesions of the salivary glands constitute ≤0.5% of all the salivary gland tumors. Oncocytic sialolipoma of the parotid glands is extremely... (Review)
Review
Neoplastic lipomatous lesions of the salivary glands constitute ≤0.5% of all the salivary gland tumors. Oncocytic sialolipoma of the parotid glands is extremely uncommon. We report a case of oncocytic sialolipoma of the parotid gland in a 59-year-old male who presented with a gradually increasing swelling of the right parotid. Excisional parotid biopsy performed in view of possible pleomorphic adenoma as suggested on ultrasonography showed histological features consistent with oncocytic sialolipoma. We also described the characteristics of 24 previously reported cases of oncocytic sialolipoma of the parotid gland. The median age of the patients including the present case was 56 years (range 7-89), and 14 were male. The largest and the least reported sizes of the tumor were 7.0 and 1.4 cm, respectively. The left-sided parotid gland was more commonly involved (14/23). Despite its rarity, oncocytic sialolipoma should be considered in lipomatous parotid lesions showing epithelial components with oncocytic changes.
Topics: Humans; Male; Child; Adolescent; Young Adult; Adult; Middle Aged; Aged; Aged, 80 and over; Female; Parotid Gland; Adenoma; Salivary Gland Neoplasms; Oxyphil Cells; Lipoma; Parotid Neoplasms
PubMed: 37530346
DOI: 10.4103/ijpm.ijpm_323_21 -
International Journal of Molecular... Mar 2023The parotid gland is one of the major salivary glands producing a serous secretion, and it plays an essential role in the digestive and immune systems. Knowledge of...
The parotid gland is one of the major salivary glands producing a serous secretion, and it plays an essential role in the digestive and immune systems. Knowledge of peroxisomes in the human parotid gland is minimal; furthermore, the peroxisomal compartment and its enzyme composition in the different cell types of the human parotid gland have never been subjected to a detailed investigation. Therefore, we performed a comprehensive analysis of peroxisomes in the human parotid gland's striated duct and acinar cells. We combined biochemical techniques with various light and electron microscopy techniques to determine the localization of parotid secretory proteins and different peroxisomal marker proteins in parotid gland tissue. Moreover, we analyzed the mRNA of numerous gene encoding proteins localized in peroxisomes using real-time quantitative PCR. The results confirm the presence of peroxisomes in all striated duct and acinar cells of the human parotid gland. Immunofluorescence analyses for various peroxisomal proteins showed a higher abundance and more intense staining in striated duct cells compared to acinar cells. Moreover, human parotid glands comprise high quantities of catalase and other antioxidative enzymes in discrete subcellular regions, suggesting their role in protection against oxidative stress. This study provides the first thorough description of parotid peroxisomes in different parotid cell types of healthy human tissue.
Topics: Humans; Parotid Gland; Peroxisomes; Proteins; Microscopy, Electron; Salivary Ducts
PubMed: 36902220
DOI: 10.3390/ijms24054783 -
Dento Maxillo Facial Radiology May 2022To provide a graded diagnosis of benign and malignant lesions in the parotid gland by conventional ultrasound, and thus to predict the probability of malignancy of the...
OBJECTIVES
To provide a graded diagnosis of benign and malignant lesions in the parotid gland by conventional ultrasound, and thus to predict the probability of malignancy of the lesions.
METHODS
Retrospective analysis of conventional ultrasound images of 150 patients with parotid lesions by two observers. Parotid lesions were classified into seven patterns and then categorised into eight grades: Grade 0, unsatisfied illustration on ultrasound; Grade 1, normal parotid gland; Grade 2, definitively benign; Grade 3, probably benign; Grade 4, indeterminate; Grade 5, probably malignant; Grade 6, highly suggestive malignant and Grade 7, already had malignant diagnosis. Combined with the pathological results, the conventional ultrasound diagnostic grade of parotid lesions was evaluated for predicting the probability of malignancy.
RESULTS
There was excellent interobserver agreement of both readers for patterns and grades ( = 0.89 and 0.90, < 0.01). The proportions of the malignancies in conventional ultrasound Grade 2, 3, 4, 5 and 6 according to the two readers 0 and 0, 0 and 0, 8.7% and 8.8%, 54.2% and 50%, 100% and 100%, respectively. The sensitivity, specificity and area under ROC curve were 64.0%, 91.2%, 0.809 and 64.0%, 89.6%, 0.802, respectively, using Grade 5 of the two readers as the best grade for diagnosing benign and malignant parotid lesions.
CONCLUSION
The conventional ultrasound diagnostic grade of parotid lesions can be used to evaluate the risk of malignancy and will be helpful to improve the imaging diagnosis and clinical treatment.
Topics: Diagnosis, Differential; Humans; Parotid Gland; Parotid Neoplasms; Pilot Projects; ROC Curve; Retrospective Studies; Sensitivity and Specificity; Ultrasonography
PubMed: 35113723
DOI: 10.1259/dmfr.20210484 -
International Journal of Radiation... Feb 2022Radiation therapy for head and neck cancer frequently leads to salivary gland damage and subsequent xerostomia. The radiation response of the parotid glands of rats,... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
Radiation therapy for head and neck cancer frequently leads to salivary gland damage and subsequent xerostomia. The radiation response of the parotid glands of rats, mice, and patients critically depends on dose to parotid gland stem cells, mainly located in the gland's main ducts (stem cell rich [SCR] region). Therefore, this double-blind randomized controlled trial aimed to test the hypothesis that parotid gland stem cell sparing radiation therapy preserves parotid gland function better than currently used whole parotid gland sparing radiation therapy.
METHODS AND MATERIALS
Patients with head and neck cancer (n = 102) treated with definitive radiation therapy were randomized between standard parotid-sparing and stem cell sparing (SCS) techniques. The primary endpoint was >75% reduction in parotid gland saliva production compared with pretreatment production (FLOW). Secondary endpoints were several aspects of xerostomia 12 months after treatment.
RESULTS
Fifty-four patients were assigned to the standard arm and 48 to the SCS arm. Only dose to the SCR regions (contralateral 16 and 11 Gy [P = .004] and ipsilateral 26 and 16 Gy [P = .001] in the standard and SCS arm, respectively) and pretreatment patient-rated daytime xerostomia (35% and 13% [P = .01] in the standard and SCS arm, respectively) differed significantly between the arms. In the SCS arm, 1 patient (2.8%) experienced FLOW compared with 2 (4.9%) in the standard arm (P = 1.00). However, a trend toward better relative parotid gland salivary function in favor of SCS radiation therapy was shown. Moreover, multivariable analysis showed that mean contralateral SCR region dose was the strongest dosimetric predictor for moderate-to-severe patient-rated daytime xerostomia and grade ≥2 physician-rated xerostomia, the latter including reported alteration in diet.
CONCLUSIONS
No significantly better parotid function was observed in SCS radiation therapy. However, additional multivariable analysis showed that dose to the SCR region was more predictive of the development of parotid gland function-related xerostomia endpoints than dose to the entire parotid gland.
Topics: Humans; Head and Neck Neoplasms; Parotid Gland; Salivary Glands; Stem Cells; Xerostomia
PubMed: 34563635
DOI: 10.1016/j.ijrobp.2021.09.023 -
European Archives of... Oct 2021To establish if day case superficial parotidectomy is feasible, safe and does not result in excess readmissions.
PURPOSE
To establish if day case superficial parotidectomy is feasible, safe and does not result in excess readmissions.
METHOD
A retrospective review was carried out of all patients listed for superficial parotidectomy with day case intent by a single surgeon between January 2016 and December 2019 inclusively. The reasons for failure of same day discharge were established. Postoperative complications and readmissions were recorded. Our approach for a superficial parotidectomy typically includes the use of a 10Fr suction drain which is removed at 4 h postoperatively if the output is less than 30 ml.
RESULTS
Ninety-one consecutive superficial parotidectomies listed for day case surgery were eligible for inclusion. Seventeen patients failed to be discharged on the same day and were admitted giving a day case success rate of 81%. Most of these (n = 9) occurred in the first year of adopting day case surgery. The most common reason to admit patients was a late finish (n = 8, 47%). Six patients (25%) were admitted due to anaesthetic complications. One patient had a surgical complication requiring admission.
CONCLUSION
Our series demonstrates that day case superficial parotidectomy using a surgical drain is feasible, safe and does not result in an unacceptable readmission rate. In our experience, surgical complications are an uncommon cause for day case failure. The most common cause for day case failure was a late finish. Postoperative complications including bleeding, seroma/salivary collection and facial nerve palsy were in keeping with or better than those quoted in the literature.
Topics: Ambulatory Surgical Procedures; Facial Paralysis; Humans; Parotid Gland; Parotid Neoplasms; Postoperative Complications; Retrospective Studies; Seroma
PubMed: 33555439
DOI: 10.1007/s00405-021-06642-7 -
Radiotherapy and Oncology : Journal of... Jul 2020To assess associations between parotid gland PET biomarkers and late radiation-induced xerostomia, and to validate improvement of xerostomia predictive models by adding...
PURPOSE
To assess associations between parotid gland PET biomarkers and late radiation-induced xerostomia, and to validate improvement of xerostomia predictive models by adding pre-treatment PET features to models based on dose and pre-treatment xerostomia.
MATERIALS AND METHODS
Intensity PET features from 47 patients treated on institutional prospective clinical trials for HPV-associated oropharyngeal squamous cell carcinoma with uniform chemoRT were analyzed. Associations between 90th percentile of the parotid gland standardized uptake values (P90) from pre-treatment and post-treatment PET scans, mean parotid gland doses, and late xerostomia defined by the Xerostomia Questionnaire (XQ) and salivary flow rates were quantified. Multivariable analysis was applied for dose and PET features using penalized logistic regression for feature selection and generation of predictive models using the LASSO technique, and optimism bias was estimated by bootstrap resampling.
RESULTS
Significant associations between late xerostomia and both mean parotid gland dose and P90 were demonstrated, and were generally stronger for post-treatment PET scans. The addition of P90 from pre-treatment PET scans improved the prediction model for late moderate or severe xerostomia compared to the base model, from AUC = 0.74 to 0.78 (p-value <0.001) for XQ summary score and from 0.77 to 0.84 (p-value <0.001) for the single eating-related XQ item with the largest inter-patient variability; however, only the latter remained significant on cross validation (AUC = 0.69 to 0.70 and 0.73 to 0.80, respectively).
CONCLUSIONS
The addition of pre-treatment parotid gland PET biomarkers improved a predictive model for late patient-reported xerostomia over dose and pre-treatment xerostomia.
Topics: Benchmarking; Biomarkers; Head and Neck Neoplasms; Humans; Parotid Gland; Positron-Emission Tomography; Prospective Studies; Xerostomia
PubMed: 32311598
DOI: 10.1016/j.radonc.2020.03.037 -
Gland Surgery Mar 2021Reports regarding the imaging findings of parotid gland oncocytoma are limited and prospective definitive diagnosis is difficult. This case series is aimed at furthering...
BACKGROUND
Reports regarding the imaging findings of parotid gland oncocytoma are limited and prospective definitive diagnosis is difficult. This case series is aimed at furthering the knowledge of imaging for parotid gland oncocytoma.
METHODS
Seven patients with pathologically confirmed parotid gland oncocytoma were identified between January, 2016 and August, 2020. They were subjected to computed tomography, magnetic resonance imaging or ultrasound. Imaging features of lesions were retrospectively analyzed and documented by a senior radiologist.
RESULTS
Among the 7 recruited parotid gland oncocytoma patients, 4 were males and 3 were females. They were aged between 47 and 87 years with a median age of 63 years. The range of maximum diameter of the mass was about 1.6-4.5 cm, with the median size being 3.5 cm. All cases were unilateral single masses. Three patients had their parotid gland oncocytoma located in the deep lobe of the parotid gland and 4 patients had their parotid gland oncocytoma located in the superficial lobe. Most lesions exhibited a clear boundary and irregular shapes or lobulated, and contain cystic components. Local pain was the most common clinical manifestation. Most of the lesions exhibited a hypoechoic mass on ultrasound, soft tissue density on computed tomography, iso to hypointense signal on T1 weighted imaging, slightly hypersignal on T2 weighted imaging, while contrast-enhanced computed tomography, magnetic resonance imaging, and ultrasound showed avid enhancement.
CONCLUSIONS
Parotid gland oncocytomas usually exhibit a clear boundary to surrounding parotid tissue, lobulated or irregular shape and avid enhancement, sometimes accompanied with cystic components. Diagnosis of parotid gland oncocytoma should be considered when these features are encountered in clinical practice.
PubMed: 33842232
DOI: 10.21037/gs-20-790 -
Journal of Dental Research Apr 2023Xerostomia is a common side effect of radiation therapy (RT) in patients with head and neck cancer. However, limited information is available on the temporal dynamics of...
Xerostomia is a common side effect of radiation therapy (RT) in patients with head and neck cancer. However, limited information is available on the temporal dynamics of parenchymal and vascular changes in salivary glands following RT. To address this gap in knowledge, we conducted experimental studies in mice employing ultrasound (US) with coregistered photoacoustic imaging (PAI) to noninvasively assess the early and late changes in salivary gland size, structure, vascularity, and oxygenation dynamics following RT. Multiparametric US-PAI of salivary glands was performed in immune-deficient and immune-competent mice before and after RT along with correlative sialometry and ex vivo histologic-immunohistochemical validation. US revealed reduction in gland volume and an early increase in vascular resistance postradiation. This was accompanied by a reduction in glandular oxygen consumption on PAI. Imaging data correlated strongly with salivary secretion and histologic evidence of acinar damage. The magnitude and kinetics of radiation response were impacted by host immune status, with immunodeficient mice showing early and more pronounced vascular injury and DNA damage response compared to immunocompetent animals. Our findings demonstrate the ability of noninvasive US-PAI to monitor dynamic changes in salivary gland hemodynamics following radiation and highlight the impact of the host immune status on salivary gland radiation injury.
Topics: Animals; Mice; Vascular System Injuries; Salivary Glands; Xerostomia; Head and Neck Neoplasms; Radiation Injuries; Parotid Gland
PubMed: 36515317
DOI: 10.1177/00220345221138533