Skip to main content
Key Specialties
Cardiology Diabetology Endocrinology Gastroenterology Geriatrics and Gerontology Gynecology and Obstetrics Hematology Infectious Disease Internal Medicine Nephrology Neurology Oncology Pediatrics Respiratory Medicine Rheumatology Surgery
Congress Coverage
2024 ACC Congress 2023 ESMO Congress 2023 EASD Congress 2023 ERS Congress 2023 ESC Congress
Clinical Collections
Advances in Alzheimer’s

At a glance: The STEP trials

A round-up of the STEP phase 3 clinical trials evaluating semaglutide for weight loss in people with overweight or obesity.
ADVANCED SEARCH
Log in
Top
Japanese Journal of Radiology
Published in: Japanese Journal of Radiology 11/2017

01-11-2017 | Review

Cystic lesions of the parotid gland: radiologic-pathologic correlation according to the latest World Health Organization 2017 Classification of Head and Neck Tumours

Authors: Hirotaka Takita, Tohru Takeshita, Taro Shimono, Hiroko Tanaka, Hiroyoshi Iguchi, Shigeo Hashimoto, Yuko Kuwae, Masahiko Ohsawa, Yukio Miki

Published in: Japanese Journal of Radiology | Issue 11/2017

Login to get access

Abstract

The latest World Health Organization 2017 Classification of Head and Neck Tumours includes a new chapter on tumors and tumor-like lesions of the neck and lymph nodes. Tumor-like lesions include a variety of cystic lesions of the parotid gland. Cystic lesions of the parotid gland can be divided into three groups: non-neoplastic cysts, benign tumors with macrocystic change, and malignant tumors with macrocystic change. It is important to distinguish these lesions from one another because treatment and patient management differ among the three groups. The purpose of this review is to describe the magnetic resonance imaging and scintigraphy findings and the histopathologic characteristics of each parotid gland lesion based on the latest World Health Organization 2017 Classification of Head and Neck Tumours and to summarize the key points of differential diagnosis for cystic lesions of the parotid gland.
Literature
1.
Katabi N, Lewis JS. Update from the 4th Edition of the World Health Organization Classification of Head and Neck Tumours: what is new in the 2017 WHO blue book for tumors and tumor-like lesions of the neck and lymph nodes. Head Neck Pathol. 2017;11:48–54.CrossRefPubMed
2.
El-Naggar AK. WHO classification of tumors of salivary glands. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 160.
3.
Work WP. Cysts and congenital lesions of the parotid gland. Otolaryngol Clin North Am. 1977;10:339–43.PubMed
4.
Bell D, Bullerdiek J, Gnepp DR, Schwartz MR, Stenman G, Triantafyllou A. Pleomorphic adenoma. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 185–6.
5.
Espinoza S, Felter A, Malinvaud D, Badoual C, Chatellier G, Siauve N, et al. Warthin’s tumor of parotid gland: surgery or follow-up? Diagnostic value of a decisional algorithm with functional MRI. Diagn Interv imaging. 2016;97:37–43.CrossRefPubMed
6.
7.
Bloemena E, Bell D, Chiosea S. Lymphoepithelial sialadenitis. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 196–7.
8.
Bullerdiek J, Flucke U. Lymphangioma. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO Classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 122–3.
9.
Chiosea S, Gnepp DR, Wenig BM. Dermoid and teratoid cysts. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 157.
10.
Katabi N, Gnepp DR, Wenig BM. Ranula. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 156–7.
11.
Ro JY, Bell D, Gnepp DR, Wenig BM. Branchial cleft cyst. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 155–6.
12.
Som PM, Brandwein MS, Silvers A. Nodal inclusion cysts of the parotid gland and parapharyngeal space: a discussion of lymphoepithelial, AIDS-related parotid, and branchial cysts, cystic Warthin’s tumors, and cysts in Sjogren’s syndrome. Laryngosc. 1995;105:1122–8.CrossRef
13.
Takeshita T, Tanaka H, Harasawa A, Kaminaga T, Imamura T, Furui S. Benign pleomorphic adenoma with extensive cystic degeneration: unusual MR findings in two cases. Radiat Med. 2004;22:357–61.PubMed
14.
Ellis GL, Auclair PL. Tumors of the salivary glands. In: Silverberg SG, editor. AFIP atlas of tumor pathology. Maryland: ARP; 2008. p. 498–9.
15.
16.
17.
Ellis GL, Auclair PL. Tumors of the salivary glands. In: Silverberg SG, editor. AFIP atlas of tumor pathology. Maryland: ARP; 2008. p. 499–500.
18.
Nakazawa T, Kondo T, Oishi N, Tahara I, Kasai K, Inoue T, et al. Branchial cleft-like cysts involving 3 different organs: thyroid gland, thymus, and parotid gland. Medicine. 2015;94:e1758.CrossRefPubMedPubMedCentral
19.
20.
Koeller KK, Alamo L, Adair CF, Smirniotopoulos JG. Congenital cystic masses of the neck: radiologic-pathologic correlation. Radiographics. 1999;19:121–46 (quiz 152–3).CrossRefPubMed
21.
Ellis GL, Auclair PL. Tumors of the salivary glands. In: Silverberg SG, editor. AFIP atlas of tumor pathology. Maryland: ARP; 2008. p. 501–4.
22.
Kirshenbaum KJ, Nadimpalli SR, Friedman M, Kirshenbaum GL, Cavallino RP. Benign lymphoepithelial parotid tumors in AIDS patients: CT and MR findings in nine cases. AJNR. 1991;12:271–4.PubMed
23.
Yigit N, Karslioglu Y, Yildizoglu U, Karakoc O. Dermoid cyst of the parotid gland: report of a rare entity with literature review. Head Neck Pathol. 2015;9:286–92.CrossRefPubMed
24.
Devine JC, Jones DC. Carcinomatous transformation of a sublingual dermoid cyst. A case report. Int J Oral Maxillofac Surg. 2000;29:126–7.CrossRefPubMed
25.
Nishie A, Yoshimitsu K, Honda H, Irie H, Aibe H, Shinozaki K, et al. Presacral dermoid cyst with scanty fat component: usefulness of chemical shift and diffusion-weighted MR imaging. Comput Med Imaging Gr. 2003;27:293–6.CrossRef
26.
Wiegand S, Zimmermann AP, Eivazi B, Sesterhenn AM, Werner JA. Lymphatic malformations involving the parotid gland. Eur J Pediatr Surg. 2011;21:242–5.CrossRefPubMed
27.
White CL, Olivieri B, Restrepo R, McKeon B, Karakas SP, Lee EY. Low-flow vascular malformation pitfalls: from clinical examination to practical imaging evaluation-part 1, lymphatic malformation mimickers. AJR. 2016;206:940–51.CrossRefPubMed
28.
Harada H. Differential diagnosis of the salivary gland tumor with the cyst formation. [Nouhoukeisei wo tomonau daekisen syuyo no kanbetu]. In: Morinaga S, Takata T, Nagao T, editors. Head and neck tumors 1. [Toukeibu syuyo 1]. Tokyo: Bunkodo; 2015. p. 170–5.
29.
Christe A, Waldherr C, Hallett R, Zbaeren P, Thoeny H. MR imaging of parotid tumors: typical lesion characteristics in MR imaging improve discrimination between benign and malignant disease. AJNR. 2011;32:1202–7.CrossRefPubMed
30.
Eida S, Sumi M, Sakihama N, Takahashi H, Nakamura T. Apparent diffusion coefficient mapping of salivary gland tumors: prediction of the benignancy and malignancy. AJNR. 2007;28:116–21.PubMed
31.
Matsushima N, Maeda M, Takamura M, Takeda K. Apparent diffusion coefficients of benign and malignant salivary gland tumors. Comparison to histopathological finding. J Neuroradiol. 2007;34:183–9.CrossRefPubMed
32.
Takashima S, Noguchi Y, Okumura T, Aruga H, Kobayashi T. Dynamic MR imaging in the head and neck. Radiology. 1993;189:813–21.CrossRefPubMed
33.
Lam PD, Kuribayashi A, Imaizumi A, Sakamoto J, Sumi Y, Yoshino N, et al. Differentiating benign and malignant salivary gland tumours: diagnostic criteria and the accuracy of dynamic contrast-enhanced MRI with high temporal resolution. Br J Radiol. 2015;88:20140685.CrossRefPubMedPubMedCentral
34.
Nagao T, Gnepp DR, Simpson RHW, Vielh P. Warthin tumor. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 188–9.
35.
Nagao T, Sugano I, Ishida Y, Tajima Y, Furuya N, Kondo Y, et al. Mucoepidermoid carcinoma arising in Warthin’s tumour of the parotid gland: report of two cases with histopathological, ultrastructural and immunohistochemical studies. Histopathology. 1998;33:379–86.CrossRefPubMed
36.
Ellis GL, Auclair PL. Tumors of the salivary glands. In: Silverberg SG, editor. AFIP atlas of tumor pathology. Maryland: ARP; 2008. p. 85–116.
37.
Ikeda M, Motoori K, Hanazawa T, Nagai Y, Yamamoto S, Ueda T, et al. Warthin tumor of the parotid gland: diagnostic value of MR imaging with histopathologic correlation. AJNR. 2004;25:1256–62.PubMed
38.
Yabuuchi H, Matsuo Y, Kamitani T, Setoguchi T, Okafuji T, Soeda H, et al. Parotid gland tumors: can addition of diffusion-weighted MR imaging to dynamic contrast-enhanced MR imaging improve diagnostic accuracy in characterization? Radiology. 2008;249:909–16.CrossRefPubMed
39.
Habermann CR, Arndt C, Graessner J, Diestel L, Petersen KU, Reitmeier F, et al. Diffusion-weighted echo-planar MR imaging of primary parotid gland tumors: is a prediction of different histologic subtypes possible? AJNR. 2009;30:591–6.CrossRefPubMed
40.
Kato H, Kanematsu M, Watanabe H, Mizuta K, Aoki M. Salivary gland tumors of the parotid gland: CT and MR imaging findings with emphasis on intratumoral cystic components. Neuroradiology. 2014;56:789–95.CrossRefPubMed
41.
Minami M, Tanioka H, Oyama K, Itai Y, Eguchi M, Yoshikawa K, et al. Warthin tumor of the parotid gland: MR-pathologic correlation. AJNR. 1993;14:209–14.PubMed
42.
Uchida Y, Minoshima S, Kawata T, Motoori K, Nakano K, Kazama T, et al. Diagnostic value of FDG PET and salivary gland scintigraphy for parotid tumors. Clin Nucl Med. 2005;30:170–6.CrossRefPubMed
43.
Miyake H, Matsumoto A, Hori Y, Takeoka H, Kiyosue H, Hori Y, et al. Warthin’s tumor of parotid gland on Tc-99m pertechnetate scintigraphy with lemon juice stimulation: Tc-99m uptake, size, and pathologic correlation. Eur Radiol. 2001;11:2472–8.CrossRefPubMed
44.
Kawano H, Kimura T, Kikuchi N, Ishii A, Ikeda E. Stroma-poor Warthin’s tumor with significant oncocytic hyperplasia: case presentation and considerations regarding its histogenesis. Rom J Morphol Embryol. 2016;57:585–90.PubMed
45.
Eveson JW, Cawson RA. Infarcted (‘infected’) adenolymphomas. A clinicopathological study of 20 cases. Clin Otolaryngol Allied Sci. 1989;14:205–10.CrossRefPubMed
46.
Seifert G, Bull HG, Donath K. Histologic subclassification of the cystadenolymphoma of the parotid gland. Analysis of 275 cases. Virchows Arch A Pathol Anat Histol. 1980;388:13–38.CrossRefPubMed
47.
Di Palma S, Simpson RH, Skálová A, Michal M. Metaplastic (infarcted) Warthin’s tumour of the parotid gland: a possible consequence of fine needle aspiration biopsy. Histopathology. 1999;35:432–8.CrossRefPubMed
48.
Kato H, Kanematsu M, Mizuta K, Aoki M, Hirose Y. Spontaneous infarction of Warthin’s tumor: imaging findings simulating malignancy. Jpn J Radiol. 2012;30:354–7.CrossRefPubMed
49.
Budnick S, Simpson RHW. Cystadenoma. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 191.
50.
51.
Ellis GL, Auclair PL. Tumors of the salivary glands. In: Silverberg SG, editor. AFIP atlas of tumor pathology. Maryland: ARP; 2008. p. 49–71.
52.
Lopes ML, Barroso KM, Henriques ÁC, Dos Santos JN, Martins MD, de Souza LB. Pleomorphic adenomas of the salivary glands: retrospective multicentric study of 130 cases with emphasis on histopathological features. Eur Arch Otorhinolaryngol. 2017;274:543–51.CrossRefPubMed
53.
Ikeda K, Katoh T, Ha-Kawa SK, Iwai H, Yamashita T, Tanaka Y. The usefulness of MR in establishing the diagnosis of parotid pleomorphic adenoma. AJNR. 1996;17:555–9.PubMed
54.
Kikuchi M, Koyasu S, Shinohara S, Imai Y, Hino M, Naito Y. Preoperative diagnostic strategy for parotid gland tumors using diffusion-weighted MRI and technetium-99m pertechnetate scintigraphy: a prospective study. PLoS One. 2016;11:e0148973.CrossRefPubMedPubMedCentral
55.
Motoori K, Yamamoto S, Ueda T, Nakano K, Muto T, Nagai Y, et al. Inter- and intratumoral variability in magnetic resonance imaging of pleomorphic adenoma: an attempt to interpret the variable magnetic resonance findings. J Comput Assist Tomogr. 2004;28:233–46.CrossRefPubMed
56.
Celebi I, Mahmutoglu AS, Ucgul A, Ulusay SM, Basak T, Basak M. Quantitative diffusion-weighted magnetic resonance imaging in the evaluation of parotid gland masses: a study with histopathological correlation. Clin Imaging. 2013;37:232–8.CrossRefPubMed
57.
Yerli H, Agildere AM, Aydin E, Geyik E, Haberal N, Kaskati T, et al. Value of apparent diffusion coefficient calculation in the differential diagnosis of parotid gland tumors. Acta Radiol. 2007;48:980–7.CrossRefPubMed
58.
Mukai H, Motoori K, Horikoshi T, Takishima H, Nagai Y, Okamoto Y, et al. Basal cell adenoma of the parotid gland; MR features and differentiation from pleomorphic adenoma. Dentomaxillofac Radiol. 2016;45:20150322.CrossRefPubMedPubMedCentral
59.
Kato H, Kanematsu M, Mizuta K, Aoki M. Imaging findings of parapharyngeal space pleomorphic adenoma in comparison with parotid gland pleomorphic adenoma. Jpn J Radiol. 2013;31:724–30.CrossRefPubMed
60.
Li J, Fonseca I. Basal cell adenoma. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 187–8.
61.
Seifert G. Carcinoma in basal cell adenoma of the parotid gland. Pathol Res Pract. 1997;193:659–60.CrossRefPubMed
62.
Nagao K, Matsuzaki O, Saiga H, Sugano I, Shigematsu H, Kaneko T, et al. Histopathologic studies of basal cell adenoma of the parotid gland. Cancer. 1982;50:736–45.CrossRefPubMed
63.
Okahara M, Kiyosue H, Matsumoto S, Hori Y, Tanoue S, Uchida D, et al. Basal cell adenoma of the parotid gland: MR imaging findings with pathologic correlation. AJNR. 2006;27:700–4.PubMed
64.
Chiang CW, Chang YL, Lou PJ. Multicentricity of intraparotid facial nerve schwannomas. Ann Otol Rhinol Laryngol. 2001;110:871–4.CrossRefPubMed
65.
Guzzo M, Ferraro L, Ibba T, Quattrone P, Bianchi R, Rezzonico S, et al. Schwannoma in the parotid gland. Experience at our institute and review of the literature. Tumori. 2009;95:846–51.PubMed
66.
67.
68.
Shimizu K, Iwai H, Ikeda K, Sakaida N, Sawada S. Intraparotid facial nerve schwannoma: a report of five cases and an analysis of MR imaging results. AJNR. 2005;26:1328–30.PubMed
69.
Ellis GL, Auclair PL. Tumors of the salivary glands. In: Silverberg SG, editor. AFIP atlas of tumor pathology. Maryland: ARP; 2008. p. 204–25.
70.
Simpson RHW, Chiosea S, Katabi N, Leivo I, Vielh P, Williams MD. Acinic cell carcinoma. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 166–7.
71.
Suh SI, Seol HY, Kim TK, Lee NJ, Kim JH, Kim KA, et al. Acinic cell carcinoma of the head and neck: radiologic-pathologic correlation. J Comput Assist Tomogr. 2005;29:121–6.CrossRefPubMed
72.
Ellis GL, Auclair PL. Tumors of the salivary glands. In: Silverberg SG, editor. AFIP atlas of tumor pathology. Maryland: ARP; 2008. p. 173–204.
73.
Brandwein-Gensler M, Bell D, Inagaki H, Katabi N, Leivo I, Seethala R, et al. Mucoepidermoid carcinoma. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 163–4.
74.
Motoori K, Iida Y, Nagai Y, Yamamoto S, Ueda T, Funatsu H, et al. MR imaging of salivary duct carcinoma. AJNR. 2005;26:1201–6.PubMed
75.
Freling NJ, Molenaar WM, Vermey A, Mooyaart EL, Panders AK, Annyas AA, et al. Malignant parotid tumors: clinical use of MR imaging and histologic correlation. Radiology. 1992;185:691–6.CrossRefPubMed
76.
Vogl TJ, Dresel SH, Spath M, Grevers G, Wilimzig C, Schedel HK, et al. Parotid gland: plain and gadolinium-enhanced MR imaging. Radiology. 1990;177:667–74.CrossRefPubMed
77.
Som PM, Biller HF. High-grade malignancies of the parotid gland: identification with MR imaging. Radiology. 1989;173:823–6.CrossRefPubMed
78.
Kashiwagi N, Dote K, Kawano K, Tomita Y, Murakami T, Nakanishi K, et al. MRI findings of mucoepidermoid carcinoma of the parotid gland: correlation with pathological features. Br J Radiol. 2012;85:709–13.CrossRefPubMedPubMedCentral
79.
Ellis GL, Auclair PL. Tumors of the salivary glands. In: Silverberg SG, editor. AFIP atlas of tumor pathology. Maryland: ARP; 2008. p. 281–9.
80.
Foss RD, Ellis GL, Auclair PL. Salivary gland cystadenocarcinomas. A clinicopathologic study of 57 cases. Am J Surg Pathol. 1996;20:1440–7.CrossRefPubMed
81.
Leivo I, Brandwein-Gensler M, Fonseca I, Katabi N, Loening T, Simpson RHW. Adenocarcinoma NOS. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 171–2.
82.
Koç M, Yanilmaz M, Yildirim H, Gök U, Cobanoğlu B. MRI findings of papillary cystadenocarcinoma of the submandibular gland. Diagn Interv Radiol. 2010;16:20–3.PubMed
83.
Enomoto K, Yamashita H, Harada H, Shibuya H, Noguchi H, Yoshida M, et al. A case of cystadenocarcinoma of the ectopic salivary gland: comparison of pre-operative ultrasound, CT and MR images with the pathological specimen. Dentomaxillofac Radiol. 2012;41:349–54.CrossRefPubMedPubMedCentral
84.
Williams MD, Ihrler S, Seethala R. Carcinoma ex pleomorphic adenoma. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 176–7.
85.
Kashiwagi N, Murakami T, Chikugo T, Tomita Y, Kawano K, Nakanishi K, et al. Carcinoma ex pleomorphic adenoma of the parotid gland. Acta Radiol. 2012;53:303–6.CrossRefPubMed
86.
Kato H, Kanematsu M, Mizuta K, Ito Y, Hirose Y. Carcinoma ex pleomorphic adenoma of the parotid gland: radiologic-pathologic correlation with MR imaging including diffusion-weighted imaging. AJNR. 2008;29:865–7.CrossRefPubMed
87.
Seethala R, Bell D, Fonseca I, Katabi N. Epithelial-myoepithelial carcinoma. In: El-Naggar AK, Chan JKC, Grandis JR, Takata T, Slootweg PJ, editors. WHO classification of head and neck tumours. 4th ed. Lyon: IARC; 2017. p. 175–6.
88.
Silvers AR, Som PM, Brandwein M. Epithelial-myoepithelial carcinoma of the parotid gland. AJNR. 1996;17:560–2.PubMed
89.
Takumi K, Fukukura Y, Kamiyama T, Nakajo M, Ohori J, Kurono Y, et al. Epithelial-myoepithelial carcinoma of the parotid gland: correlation of dynamic magnetic resonance imaging, (18)F-fluorodeoxyglucose-positron emission tomography, and pathological findings. Jpn J Radiol. 2010;28:618–22.CrossRefPubMed
90.
Maurer MH, Gartenschläger S, Dietrich C. Giant epithelial-myoepithelial carcinoma of the parotid gland. Clin Imaging. 2009;33:237–9.CrossRefPubMed
Metadata
Title
Cystic lesions of the parotid gland: radiologic-pathologic correlation according to the latest World Health Organization 2017 Classification of Head and Neck Tumours
Authors
Hirotaka Takita
Tohru Takeshita
Taro Shimono
Hiroko Tanaka
Hiroyoshi Iguchi
Shigeo Hashimoto
Yuko Kuwae
Masahiko Ohsawa
Yukio Miki
Publication date
01-11-2017
Publisher
Springer Japan
Published in
Japanese Journal of Radiology / Issue 11/2017
Print ISSN: 1867-1071
Electronic ISSN: 1867-108X
DOI
https://doi.org/10.1007/s11604-017-0678-z

Other articles of this Issue 11/2017

Japanese Journal of Radiology 11/2017 Go to the issue

Letter to the Editor

Fear of linear gadolinium-based contrast agents and the Japanese radiologist’s choice

Original Article

Appropriate imaging utilization in Japan: a survey of accredited radiology training hospitals

Original Article

Differentiating primary hepatic angiosarcomas from hemangiomatosis and epithelioid hemangioendotheliomas using gadoxetic acid-enhanced and diffusion-weighted MR imaging

Original Article

Extraction of the subpleural lung region from computed tomography images to detect interstitial lung disease

Special Report

Radiological assessment of the skeletal remains from Hiraizumi, Japan: review of results from the 1950 investigation

Original Article

Clinical outcomes of concurrent chemoradiotherapy with volumetric modulated arc therapy in patients with locally advanced nasopharyngeal carcinoma