title: Patterns of nodal failure after intensity modulated radiotherapy for nasopharyngeal carcinoma.
abstract: To evaluate the sites of nodal failure (NF) of nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT).
  
  
  
  Retrospective chart review.
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
  
  
  
  4. Laryngoscope, 2016 127:377-382, 2017.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, U.S.A.|Department of Radiation Oncology, Jiangxi Cancer Hospital, Nanchang, Jiangxi, China.
authors.forename: Jin-Gao
authors.initials: JG
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, U.S.A.
authors.forename: Praveen
authors.initials: P
authors.lastname: Venigalla
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, U.S.A.
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Leeman
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, U.S.A.
authors.forename: Quincey
authors.initials: Q
authors.lastname: LaPlant
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, U.S.A.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Setton
authors.affiliation: Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, U.S.A.
authors.forename: Eric
authors.initials: E
authors.lastname: Sherman
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, U.S.A.
authors.forename: Jillian
authors.initials: J
authors.lastname: Tsai
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, U.S.A.
authors.forename: Sean
authors.initials: S
authors.lastname: McBride
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, U.S.A.
authors.forename: Nadeem
authors.initials: N
authors.lastname: Riaz
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York, U.S.A.
authors.forename: Nancy
authors.initials: N
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Nasopharyngeal carcinoma; intensity modulated radiation therapy; patterns of failure