title: Can carotid-sparing radiotherapy approaches replace with conventional techniques for the patients with T1 glottic larynx cancer?
abstract: OBJECTIVE
  This study aims to compare the carotid artery doses applied with various radiotherapy techniques for the treatment of T1N0 glottic larynx cancer.
  
  
  METHODS
  Five patients were simulated with using computed tomography (CT). Clinical (CTV) and planning target volumes (PTV) were created for T1N0 glottic larynx cancer. Planning risk volumes (PRV) were constructed for carotid arteries and spinal cord. Three irradiation planning, opposed lateral box field (OLBF), three dimension conformal radiation therapy (3DCRT), intensity modulated radiation therapy (IMRT) were done for each patient. Over 95% of planned target volumes were loaded with predetermined dose (a total of 62.25 Gy of 2.25 Gy daily dose).
  
  
  RESULTS
  The comparison of the treatment planning of five T1 glottic larynx cancer, three involving the right vocal cord and two involving the left vocal cord, the technique of IMRT planning was provided the best carotid-sparing doses. Mean carotid V35, V50, and V63 values including OLBF, 3DCRT, and IMRT were 70%, 47%, 35%; 55%, 15%, 5% and 28%, 6%, 0%, respectively. The statistical comparison of V35, V50 and V63 revealed significant values for OLBF and IMRT. Dose of spinal cord did not exceed 45 Gy for any of radiation treatment planning. Between the three techniques, there was no significant difference in terms of conformity index and dose distribution was homogenous with all techniques.
  
  
  CONCLUSIONS
  It is obvious that IMRT planning technique can decrease the carotid artery radiation doses in early stage glottic larynx cancer.
authors.affiliation: Department of Radiation Oncology, Van Regional Training and Research Hospital, Van, Turkey. gracilis81@yahoo.com
authors.forename: Fatma
authors.initials: F
authors.lastname: Sert
authors.forename: Omür
authors.initials: O
authors.lastname: Karakoyun-Çelik
authors.forename: Mustafa Adnan
authors.initials: MA
authors.lastname: Esassolak
mesh_terms: D002339:Carotid Arteries / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005931:Glottis; D006801:Humans; D007822:Laryngeal Neoplasms / Q000532:radiotherapy*; D011874:Radiometry; D011878:Radiotherapy / Q000379:methods / Q000592:standards; D050397:Radiotherapy, Intensity-Modulated / Q000592:standards; D012189:Retrospective Studies; D013116:Spinal Cord / Q000528:radiation effects; D014057:Tomography, X-Ray Computed