title: Outcome and patterns of failure after postoperative intensity modulated radiotherapy for locally advanced or high-risk oral cavity squamous cell carcinoma.
abstract: BACKGROUND
  To determine the outcome and patterns of failure in oral cavity cancer (OCC) patients after postoperative intensity modulated radiotherapy (IMRT) with concomitant systemic therapy.
  
  
  METHODS
  All patients with locally advanced (AJCC stage III/IV) or high-risk OCC (AJCC stage II) who underwent postoperative IMRT at our institution between December 2006 and July 2010 were retrospectively analyzed. The primary endpoint was locoregional recurrence-free survival (LRRFS). Secondary endpoints included distant metastasis-free survival (DMFS), overall survival (OS), acute and late toxicities.
  
  
  RESULTS
  Overall 53 patients were analyzed. Twenty-three patients (43%) underwent concomitant chemotherapy with cisplatin, two patients with carboplatin (4%) and four patients were treated with the monoclonal antibody cetuximab (8%).At a median follow-up of 2.3 (range, 1.1-4.6) years the 3-year LRRFS, DMFS and OS estimates were 79%, 90%, and 73% respectively. Twelve patients experienced a locoregional recurrence. Eight patients, 5 of which had both a flap reconstruction and extracapsular extension (ECE), showed an unusual multifocal pattern of recurrence. Ten locoregional recurrences occurred marginally or outside of the high-risk target volumes. Acute toxicity grades of 2 (27%) and 3 (66%) and late toxicity grades of 2 (34%) and 3 (11%) were observed.
  
  
  CONCLUSIONS
  LRRFS after postoperative IMRT is satisfying and toxicity is acceptable. The majority of locoregional recurrences occurred marginally or outside of the high-risk target volumes. Improvement of high-risk target volume definition especially in patients with flap reconstruction and ECE might transfer into better locoregional control.
authors.affiliation: Radiation Medicine Program, Princess Margaret Hospital, Toronto, Canada.
authors.forename: Andreas
authors.initials: A
authors.lastname: Geretschläger
authors.forename: Beat
authors.initials: B
authors.lastname: Bojaxhiu
authors.forename: Susanne
authors.initials: S
authors.lastname: Crowe
authors.forename: Andreas
authors.initials: A
authors.lastname: Arnold
authors.forename: Peter
authors.initials: P
authors.lastname: Manser
authors.forename: Wock
authors.initials: W
authors.lastname: Hallermann
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Aebersold
authors.forename: Pirus
authors.initials: P
authors.lastname: Ghadjar
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000532:radiotherapy*; D009364:Neoplasm Recurrence, Local; D011184:Postoperative Period; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome