title: Cervical lymph node metastases from unknown primary cancer: a single-institution experience with intensity-modulated radiotherapy.
abstract: OBJECTIVE
  To determine the effectiveness and rate of complications of intensity-modulated radiotherapy (IMRT) in the treatment of cervical lymph node metastases from unknown primary cancer.
  
  
  METHODS
  Between February 2005 and November 2008, 25 patients with an unknown primary cancer underwent IMRT, with a median radiation dose of 70 Gy. The bilateral neck and ipsilateral putative pharyngeal mucosa were included in the target volume. All patients had squamous cell carcinoma, except for 1 patient who had adenosquamous differentiation. They were all treated with curative intent. Of the 25 included patients, 20 were men and 5 were women, with a median age of 54 years. Of these patients, 3 had Stage III, 18 had Stage IVa, and 4 had Stage IVb. Of the 25 patients, 18 (72%) received platinum-based chemotherapy in a combined-modality setting. Neck dissection was reserved for residual disease after definitive IMRT. Overall survival, disease-free survival, and locoregional control were calculated using the Kaplan-Meier method.
  
  
  RESULTS
  With a median follow-up of 38 months, the overall survival, disease-free survival, and locoregional control rates were all 100% at 3 years. No occurrence of primary cancer was observed during the follow-up period. The reported rates of xerostomia reduced with the interval from the completion of treatment. Nine patients (36%) reported Grade 2 or greater xerostomia at 6 months, and only 2 (8%) of them reported the same grade of salivary function toxicity after 24 months of follow-up.
  
  
  CONCLUSIONS
  In our institution, IMRT for unknown primary cancer has provided good overall and disease-free survival in all the patients with an acceptable rate of complications. IMRT allowed us to address the bilateral neck and ipsilateral putative pharyngeal mucosa with minimal late salivary function toxicity. The use of concurrent chemotherapy and IMRT for more advanced disease led to good clinical results with reasonable toxicities.
authors.affiliation: Department of Radiation Oncology, Centre hospitalier de l'Université de Montréal, Montréal, QC, Canada. hugo.villeneuve@umontreal.ca
authors.forename: Hugo
authors.initials: H
authors.lastname: Villeneuve
authors.forename: Philippe
authors.initials: P
authors.lastname: Després
authors.forename: Bernard
authors.initials: B
authors.lastname: Fortin
authors.forename: Edith
authors.initials: E
authors.lastname: Filion
authors.forename: David
authors.initials: D
authors.lastname: Donath
authors.forename: Denis
authors.initials: D
authors.lastname: Soulières
authors.forename: Louis
authors.initials: L
authors.lastname: Guertin
authors.forename: Tarek
authors.initials: T
authors.lastname: Ayad
authors.forename: Apostolos
authors.initials: A
authors.lastname: Christopoulos
authors.forename: Phuc Felix
authors.initials: PF
authors.lastname: Nguyen-Tan
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D018196:Carcinoma, Adenosquamous / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary; D059248:Chemoradiotherapy / Q000379:methods; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary; D006801:Humans; D015182:Lymphatic Irradiation / Q000379:methods*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009333:Neck; D009367:Neoplasm Staging; D009382:Neoplasms, Unknown Primary / Q000188:drug therapy / Q000473:pathology*; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D016019:Survival Analysis; D014987:Xerostomia / Q000209:etiology / Q000473:pathology