title: Efficacy and toxicity of chemoradiotherapy using intensity-modulated radiotherapy for unknown primary of head and neck.
abstract: OBJECTIVE
  No single standard treatment paradigm is available for head-and-neck squamous cell carcinoma of an unknown primary (HNCUP). Bilateral neck radiotherapy with mucosal axis irradiation is widely used, with or without chemotherapy and/or surgical resection. Intensity-modulated radiotherapy (IMRT) is a highly conformal method for delivering radiation that is becoming the standard of care and might reduce the long-term treatment-related sequelae. We report the Dana-Farber Cancer Institute experience with IMRT-based treatment for HNCUP.
  
  
  METHODS
  A retrospective study of all patients treated at the Dana-Farber Cancer Institute for HNCUP with IMRT between August 2004 and January 2009. The primary endpoint was overall survival; the secondary endpoints were locoregional and distant control, and acute and chronic toxicity.
  
  
  RESULTS
  A total of 24 patients with HNCUP were included. Of these patients, 22 had Stage N2 disease or greater. All patients underwent neck computed tomography, positron emission tomography-computed tomography, and examination under anesthesia with directed biopsies. Of the 24 patients, 22 received concurrent chemotherapy, and 7 (29%) also underwent induction chemotherapy. The median involved nodal dose was 70 Gy, and the median mucosal dose was 60 Gy. With a median follow-up of 2.1 years, the 2-year actuarial overall survival and locoregional control rate was 92% and 100%, respectively. Only 25% of the patients had Grade 2 xerostomia, although 11 patients (46%) required esophageal dilation for stricture.
  
  
  CONCLUSIONS
  In a single-institution series, IMRT-based chemoradiotherapy for HNCUP was associated with superb overall survival and locoregional control. The xerostomia rates were promising, but the aggressive therapy was associated with significant rates of esophageal stenosis.
authors.affiliation: Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Boston, MA 02115, USA. dsher@lroc.harvard.edu
authors.forename: David J
authors.initials: DJ
authors.lastname: Sher
authors.forename: Tracy A
authors.initials: TA
authors.lastname: Balboni
authors.forename: Robert I
authors.initials: RI
authors.lastname: Haddad
authors.forename: Charles M
authors.initials: CM
authors.lastname: Norris
authors.forename: Marshall R
authors.initials: MR
authors.lastname: Posner
authors.forename: Lori J
authors.initials: LJ
authors.lastname: Wirth
authors.forename: Laura A
authors.initials: LA
authors.lastname: Goguen
authors.forename: Donald
authors.initials: D
authors.lastname: Annino
authors.forename: Roy B
authors.initials: RB
authors.lastname: Tishler
mesh_terms: D000368:Aged; D001900:Boston; D002173:Cancer Care Facilities; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D003131:Combined Modality Therapy / Q000009:adverse effects / Q000379:methods; D004940:Esophageal Stenosis / Q000209:etiology; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009382:Neoplasms, Unknown Primary / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects; D012189:Retrospective Studies; D014987:Xerostomia / Q000209:etiology