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Patterns of nodal failure after intensity modulated radiotherapy for nasopharyngeal carcinoma
Author(s) -
Li Jingao,
Venigalla Praveen,
Leeman Jonathan E.,
LaPlant Quincey,
Setton Jeremy,
Sherman Eric,
Tsai Jillian,
McBride Sean,
Riaz Nadeem,
Lee Nancy
Publication year - 2017
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1002/lary.26139
Subject(s) - parotid gland , nasopharyngeal carcinoma , medicine , radiation therapy , radiation treatment planning , stage (stratigraphy) , retrospective cohort study , radiology , surgery , pathology , biology , paleontology
Objectives To evaluate the sites of nodal failure (NF) of nasopharyngeal carcinoma (NPC) treated with intensity‐modulated radiation therapy (IMRT). Study Design Retrospective chart review. Methods We reviewed the records of 165 patients with nonmetastatic NPC treated with IMRT between July 1998 and April 2011 at our institution. Recurrent nodes were delineated on imaging and coregistered with the original treatment planning computed tomography. Failures were assessed as in‐field, out‐field, or marginal based on the relative volumes of the recurrent nodes covered by the original dose distribution. Results Ten patients had NF at a median follow‐up of 70.4 months for surviving patients. The 3‐ and 5‐year overall survival and NF rates were 88.7%, 76.0% and 5.8%, 7.7%, respectively. Six of the nodal failures were in‐field, of which five occurred in level II; whereas four had out‐field failures, all of which were in the protected parotid gland area. There were no recurrences in level 1b despite this region being protected. The cumulative 3‐ and 5‐year failure rates in the parotid gland area were 2.2% and 3.1%, respectively. Three patients with parotid failure initially had subcentimeter, nonspecific nodules in the same locations of the parotid gland as the recurrent nodes. Conclusion Nodal failure is uncommon after IMRT in NPC. Recurrence in the parotid gland region accounts for all of the out‐field failures and 40% of NF in our study. Comprehensive assessment of nodules in or around the parotid gland is therefore a key aspect of treatment planning and follow‐up. Level of Evidence 4. Laryngoscope , 2016 127:377–382, 2017