title: Clinical and dosimetric evaluation of RapidArc versus standard sliding window IMRT in the treatment of head and neck cancer.
abstract: BACKGROUND
  Several planning studies have already proven the substantial dosimetric advantages of RapidArc (RA) over standard intensity-modulated radiotherapy. We retrospectively compared RapidArc and standard sliding window IMRT (swIMRT) in locally advanced head and neck cancer, looking both at dosimetrics as well as toxicity and outcome.
  
  
  METHODS
  CT datasets of 78 patients treated with swIMRT and 79 patients treated with RA were included. To compare the resulting dose distributions, the dose-volume parameters were evaluated for the planning target volumes (PTVs), clinical target volumes (CTVs), and organs at risk (OARs), and the number of MU were calculated. Acute toxicity was assessed by the Common Toxicity Criteria version 3.0.
  
  
  RESULTS
  PTV coverage with the 95% isodose was slightly better for RA. Dose distribution has proven to be significantly more homogenous with RA and led to a reduction of 62% in MU with better OAR sparing. As for toxicity, more grade 3 mucositis and dysphagia was observed for swIMRT, though we observed more grade 3 dermatitis for RA.
  
  
  CONCLUSIONS
  In our retrospective analysis, RA had better target coverage and better sparing of the OAR. Overall, the grade of acute toxicity was lower for RA than for swIMRT for the same types of tumor locations, except for the grade of dermatitis.
authors.affiliation: Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium, stephanie_smet99@hotmail.com.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Smet
authors.forename: Maarten
authors.initials: M
authors.lastname: Lambrecht
authors.forename: Bianca
authors.initials: B
authors.lastname: Vanstraelen
authors.forename: Sandra
authors.initials: S
authors.lastname: Nuyts
mesh_terms: D001530:Belgium; D001822:Body Burden; D015897:Comorbidity; D005260:Female; D006258:Head and Neck Neoplasms / Q000401:mortality* / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011832:Radiation Injuries / Q000401:mortality*; D011874:Radiometry / Q000706:statistics & numerical data*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000706:statistics & numerical data; D050397:Radiotherapy, Intensity-Modulated / Q000145:classification / Q000706:statistics & numerical data*; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome