Background: To determine the position and dose delivery changes rules of parotid gland (PG) during the course of intensity modulated radiation therapy (IMRT) in nasopharyngeal carcinoma patients (NPC).
Materials And Methods: One hundred and forty one competed tomography (CT) images from 47 NPC patients (three images for each patient were acquired before treatment, at the 15th and 25th fraction during the treatment) who underwent radical IMRT were selected for this study. A total of 70-76Gy at 2.12-2.3 Gy/fraction/d was given to the GTVnx in 33 fractions. The distances between the lateral/medial aspects of PG and midline (DLM and DMM) at the level of odontoid process were measured. The dose differences between plan and actual delivery were calculated.
Results: The volume reductions of PGs between fractions 15 and 25 were larger than those in the first 15 fractions (4.68 ± 3.23 cc vs. 2.46 ± 4.55 cc for the right PG and 5.96 ± 2.99 cc vs. 2.06 ± 2.99 cc for the left PG). However, the percentage of gland volume receiving ≥ 30 Gy (V30) of bilateral PGs decreased more significantly in the first 15 fractions than that between fractions 15 and 25 (5.61 ± 16.04% vs. 1.14 ± 21.54% for the right PG and 6.87 ± 15.58% vs. 0.81 ± 15.94% for the left PG). The gross tumor volume of the nasopharynx (GTVnx) decreased more significantly in the first 15 fractions than that between the 15th and 25th fraction (8.23 ± 13.61 cc vs. 3.30 ± 8.09 cc). The DMM of ipsilateral PGs reduced in the first 15 fractions (0.80 ± 2.96 mm) but increased between fraction 15 and 25 (-2.19 ± 3.96 mm). While ipsilateral PG shifted into target volume but shifted out target volume between fraction 15 and 25. Parotid glands V30 was correlated with GTVnx, GTVnx reduction and DMM reduction (p<0.01).
Conclusion: Our results indicate that the reduction of GTVnx leads to the positional change of the parotid gland, which results in more significant dose change of the parotid gland in the first 15 fractions than that between fraction 15 and 25.
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http://dx.doi.org/10.1186/s13014-014-0307-2 | DOI Listing |
Cureus
September 2024
Community and Family Medicine, All India Institute of Medical Sciences (AIIMS) Deoghar, Deoghar, IND.
Introduction Salivary gland lesions include a diverse range of histological types and biological behaviors, making accurate diagnosis and effective treatment challenging for specialists. Fine needle aspiration cytology (FNAC) plays a significant role in making preoperative diagnoses and further plans of surgery. In differentiating malignant from benign salivary gland tumors, the diagnostic accuracy of fine needle aspiration cytology (FNAC) is high.
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July 2024
Oral and Maxillofacial Surgery, Goa Dental College and Hospital, Bambolim, IND.
Ann Med Surg (Lond)
August 2024
Department of Rheumatology, Faculty of Medicine, Damascus University, Damascus, Syria.
Introduction And Importance: Sjögren's Syndrome is a systemic immune disorder, manifested in dry eyes and mouth. Primary Sjögren's syndrome without ocular manifestation is seldom mentioned in the literature.
Case Presentation: The authors report a case of a 48-year-old female who complained of dryness of mouth and dysphagia for 6 months.
SAGE Open Med Case Rep
June 2024
ENT Department and Research Laboratory LR23ES01, Habib Bourguiba University Hospital, University of Sfax, Sfax, Tunisia.
Primary lymphoepithelial carcinoma of the salivary glands is an exceptional oncological condition that predominantly emerges within the parotid gland. A significant prevalence of lymphoepithelial carcinoma has been reported in the Inuit population, along with an associated positive serology for Epstein-Barr virus in these endemic regions. In this paper, we present a case of primary lymphoepithelial carcinoma of the parotid gland in a 68-year-old female patient with a history of diabetes and hypertension residing in a non-endemic area.
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April 2024
Pediatrics, Pediatrix Medical Group, Orlando Health Winnie Palmer Hospital for Women & Babies, Orlando, USA.
Parotid abscesses are sequelae of acute parotitis that are rare in pediatric patients. Common inciting causes of parotid abscesses include infection, inflammatory conditions, and ductal obstruction. This case presents a parotid abscess found in an otherwise healthy four-year-old girl.
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