title: Dose-volume analysis of locoregional recurrences in head and neck IMRT, as determined by deformable registration: a prospective multi-institutional trial.
abstract: OBJECTIVE
  Although IMRT for head and neck cancer is widely accepted, the implications of sparing normal tissue immediately adjacent to target volumes are not well known.
  
  
  METHODS
  Between 2002 and 2007, 124 patients with head and neck cancer were treated with surgery and postoperative IMRT (n=79) or definitive RT (n=45). Locoregional recurrences were analyzed for location relative to target volumes, and dosimetry.
  
  
  RESULTS
  With a median follow-up of 26.1months, a total of 16 locoregional recurrences were observed. The five-year actuarial locoregional disease-free survival was 82% [95% CI, 72-90%]. Analysis of 18 distinct sites of locoregional failure revealed that five of these failures were within the high dose clinical target volume (CTV), nine failures were at the margin of the CTV, and four recurrences were outside the CTV. The mean dose delivered to these recurrent volumes was 63.1 Gy [range: 57-68 Gy], while the mean dose to the coolest 1cc within each recurrence was 60.0 Gy [range: 51-67 Gy]. There were two periparotid recurrences observed.
  
  
  CONCLUSIONS
  We observed excellent locoregional control rates overall. The majority of recurrences occur within high dose regions of the neck and not near the spared parotid glands.
authors.affiliation: Division of Radiation Oncology, University of Alberta, Canada.
authors.forename: Amira
authors.initials: A
authors.lastname: Shakam
authors.forename: Rufus
authors.initials: R
authors.lastname: Scrimger
authors.forename: Derek
authors.initials: D
authors.lastname: Liu
authors.forename: Mohamed
authors.initials: M
authors.lastname: Mohamed
authors.forename: Matthew
authors.initials: M
authors.lastname: Parliament
authors.forename: G Colin
authors.initials: GC
authors.lastname: Field
authors.forename: Ali
authors.initials: A
authors.lastname: El-Gayed
authors.forename: Pat
authors.initials: P
authors.lastname: Cadman
authors.forename: Naresh
authors.initials: N
authors.lastname: Jha
authors.forename: Heather
authors.initials: H
authors.lastname: Warkentin
authors.forename: David
authors.initials: D
authors.lastname: Skarsgard
authors.forename: Qiaohao
authors.initials: Q
authors.lastname: Zhu
authors.forename: Sunita
authors.initials: S
authors.lastname: Ghosh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D010306:Parotid Gland / Q000528:radiation effects; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated; D016896:Treatment Outcome