title: Clipping of tumour resection margins allows accurate target volume delineation in head and neck cancer adjuvant radiation therapy.
abstract: BACKGROUND
  Accurate tumour bed localisation is a key requirement for adjuvant radiotherapy. A new procedure is described for head and neck cancer treatment that improves tumour bed localisation using titanium clips.
  
  
  METHODS
  Following complete local excision of the primary tumour, the tumour bed was marked with titanium clips. Preoperative gross target volume (GTV) and postoperative tumour bed were examined and the distances between the centres of gravity were evaluated.
  
  
  RESULTS
  49 patients with squamous cell carcinoma of the oral cavity were prospectively enrolled in this study. All patients underwent tumour resection, neck lymph node dissection and defect reconstruction in one stage. During surgery, 7-49 clips were placed in the resection cavity. Surgical clip insertion was successful in 88% (n=43). Clip identification and tumour bed delineation was successful in all 43 patients. The overall distance between the centres of gravity of the preoperative tumour extension to the tumour bed was 0.9cm. A significant relationship between the preoperative tumour extension and the postoperative tumour bed volume could be demonstrated.
  
  
  CONCLUSIONS
  We demonstrate a precise delineation of the former tumour cavity. Improvements in tumour bed delineation allow an increase of accuracy for adjuvant treatment.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Germany. Electronic address: gido.bittermann@uniklinik-freiburg.de.
authors.forename: Gido
authors.initials: G
authors.lastname: Bittermann
authors.affiliation: Department of Radiation Oncology, University Medical Center Freiburg, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Wiedenmann
authors.affiliation: Department of Radiation Oncology, University Medical Center Freiburg, Germany.
authors.forename: Andrei
authors.initials: A
authors.lastname: Bunea
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Germany.
authors.forename: Steffen J
authors.initials: SJ
authors.lastname: Schwarz
authors.affiliation: Department of Radiation Oncology, University Medical Center Freiburg, Germany.
authors.forename: Anca-L
authors.initials: AL
authors.lastname: Grosu
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Schmelzeisen
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Germany.
authors.forename: Marc C
authors.initials: MC
authors.lastname: Metzger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D018714:Radiotherapy, Adjuvant; D013525:Surgical Instruments; D047368:Tumor Burden
keywords: Adjuvant radiotherapy; Clips; Head and neck cancer; Tumour bed delineation