title: Stereotactic body radiotherapy: a promising treatment option for the boost of oropharyngeal cancers not suitable for brachytherapy: a single-institutional experience.
abstract: OBJECTIVE
  To prospectively assess the outcome and toxicity of frameless stereotactic body radiotherapy (SBRT) as a treatment option for boosting primary oropharyngeal cancers (OPC) in patients who not suitable for the standard brachytherapy boost (BTB).
  
  
  METHODS
  Between 2005 and 2010, 51 patients with Stage I to IV biopsy-proven OPC who were not suitable for BTB received boosts by means of SBRT (3 times 5.5 Gy, prescribed to the 80% isodose line), after 46 Gy of IMRT to the primary tumor and neck (when indicated). Endpoints of the study were local control (LC), disease-free survival (DFS), overall survival (OS), and acute and late toxicity.
  
  
  RESULTS
  After a median follow-up of 18 months (range, 6-65 months), the 2-year actuarial rates of LC, DFS, and OS were 86%, 80%, and 82%, respectively, and the 3-year rates were 70%, 66%, and 54%, respectively. The treatment was well tolerated, as there were no treatment breaks and no Grade 4 or 5 toxicity reported, either acute or chronic. The overall 2-year cumulative incidence of Grade ≥2 late toxicity was 28%. Of the patients with 2 years with no evidence of disease (n = 20), only 1 patient was still feeding tube dependent and 2 patients had Grade 3 xerostomia.
  
  
  CONCLUSIONS
  According to our knowledge, this study is the first report of patients with primary OPC who received boosts by means of SBRT. Patients with OPC who are not suitable for the standard BTB can safely and effectively receive boosts by SBRT. With this radiation technique, an excellent outcome was achieved. Furthermore, the SBRT boost did not have a negative impact regarding acute and late side effects.
authors.affiliation: Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Groene Hilledijk, Rotterdam, the Netherlands. a.al-mamgani@erasmusmc.nl
authors.forename: Abrahim
authors.initials: A
authors.lastname: Al-Mamgani
authors.forename: Lisa
authors.initials: L
authors.lastname: Tans
authors.forename: David N
authors.initials: DN
authors.lastname: Teguh
authors.forename: Peter
authors.initials: P
authors.lastname: van Rooij
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Zwijnenburg
authors.forename: Peter C
authors.initials: PC
authors.lastname: Levendag
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D011446:Prospective Studies; D011832:Radiation Injuries / Q000473:pathology; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*