title: Patterns of failure after intensity-modulated radiotherapy in head and neck squamous cell carcinoma using compartmental clinical target volume delineation.
abstract: OBJECTIVE
  To determine the pattern of disease recurrence in non-nasopharyngeal head and neck squamous cell carcinoma (HNSCC) patients treated with radical intensity-modulated radiotherapy (IMRT) with or without chemotherapy, and to correlate the sites of locoregional recurrence with radiotherapy target volumes.
  
  
  METHODS
  In total, 136 patients treated with radical IMRT with or without chemotherapy between 2008 and 2011 for non-nasopharyngeal HNSCC were retrospectively identified. A compartmental approach to clinical target volume (CTV) delineation was routinely utilised during this period and IMRT was delivered using a 5-7 angle step and shoot technique. Locoregional recurrences were reconstructed on the planning computed tomography scan by both deformable image coregistration and by visual assessment, and were analysed in relation to target volumes and dosimetry.
  
  
  RESULTS
  The median follow-up was 31 (range 3-53) months. Two year local control, regional control, disease-free survival, distant metastasis-free survival and overall survival were 86, 93, 78, 89 and 79%, respectively. One hundred and twenty of 136 (88%) patients achieved a complete response to treatment and 7/120 (6%) have subsequently had a locoregional recurrence. Analysis of these recurrences revealed five to be infield; one to be marginal to the high-dose CTV; one to be out-of-field. Overall the marginal/out-of-field recurrence rate was 2/136 (1.5%).
  
  
  CONCLUSIONS
  IMRT utilising a compartmental approach to CTV delineation was associated with a low rate of marginal/out-of-field recurrence.
authors.affiliation: Department of Clinical Oncology, St. James's Institute of Oncology, Leeds, UK.
authors.forename: E
authors.initials: E
authors.lastname: Bayman
authors.affiliation: Department of Clinical Oncology, St. James's Institute of Oncology, Leeds, UK. Electronic address: Robin.Prestwich@leedsth.nhs.uk.
authors.forename: R J D
authors.initials: RJ
authors.lastname: Prestwich
authors.affiliation: Department of Radiotherapy Physics, St. James's Institute of Oncology, Leeds, UK.
authors.forename: R
authors.initials: R
authors.lastname: Speight
authors.affiliation: Department of Radiotherapy Physics, St. James's Institute of Oncology, Leeds, UK.
authors.forename: L
authors.initials: L
authors.lastname: Aspin
authors.affiliation: Department of Radiotherapy Physics, St. James's Institute of Oncology, Leeds, UK.
authors.forename: L
authors.initials: L
authors.lastname: Garratt
authors.affiliation: Department of Radiotherapy Physics, St. James's Institute of Oncology, Leeds, UK.
authors.forename: S
authors.initials: S
authors.lastname: Wilson
authors.affiliation: Department of Clinical Oncology, St. James's Institute of Oncology, Leeds, UK.
authors.forename: K E
authors.initials: KE
authors.lastname: Dyker
authors.affiliation: Department of Clinical Oncology, St. James's Institute of Oncology, Leeds, UK.
authors.forename: M
authors.initials: M
authors.lastname: Sen
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D059248:Chemoradiotherapy; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000401:mortality; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D020266:Radiotherapy, Conformal; D012189:Retrospective Studies; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D017211:Treatment Failure
keywords: Chemotherapy; coregistration; head and neck cancer; intensity-modulated radiotherapy; recurrence pattern