title: Feasibility of PET-CT based hypofractionated accelerated dose escalation in oropharyngeal cancers: Final dosimetric results of the VORTIGERN study. (Secondary endpoint of UK NCRI portfolio: MREC No: 08/H0907/127, UKCRN ID 7341).
abstract: OBJECTIVE
  Technological advances have enabled clinicians to explore dose escalation strategies in various tumor sites. Intermediate and high risk oropharyngeal cancers have poor 5 year outcomes. This study aimed to assess the feasibility and dosimetric safety of 9% dose escalation in these tumors and compare the dose received by organs at risk (OAR) in escalated plans (67.2 Gy/28 fractions) versus (65 Gy/30 fractions) standard dose plans.
  
  
  METHODS
  FDG-PET fused datasets were used to delineate gross, clinical and planning target volumes. Standard dose plans were created using two non IMRT techniques (conventional and field in field plans) whilst the patient was treated using a helical tomotherapy plan. A fourth dose escalation plan was obtained allowing comparison between the 20 plans of oropharyngeal cancer patients.
  
  
  RESULTS
  It was feasible to escalate dose to the FDG-PET avid tumor within the set constraints to that of planning target volume and OAR. Comparison of the escalated dose to that of standard plans showed a statistically significant (P < 0.05) sparing of the mastication apparatus (MA) with escalated plans. Dose to the other critical and functional organs were comparable between the four plans.
  
  
  CONCLUSIONS
  Hypofractionated, slightly accelerated dose escalation in oropharyngeal cancers is likely to be safe and the chance of trismus is not any higher than when standard dose radiotherapy is used. Active measures to reduce dose to the MA achieves acceptable dose volume parameters even at escalated doses.
authors.affiliation: Department of Radiation Oncology, Tata Medical Center, Kolkata, India.
authors.forename: Sanjoy
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Charles
authors.initials: C
authors.lastname: Kelly
authors.forename: Moses
authors.initials: M
authors.lastname: Arunsingh
authors.forename: Chandan
authors.initials: C
authors.lastname: Chakrabarty
authors.forename: Judith
authors.initials: J
authors.lastname: Mott
mesh_terms: D019583:Dose Fractionation, Radiation; D006801:Humans; D009959:Oropharyngeal Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D049268:Positron-Emission Tomography / Q000379:methods; D000069473:Radiation Dose Hypofractionation; D011874:Radiometry / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D020266:Radiotherapy, Conformal / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods