title: A PET-based nomogram for oropharyngeal cancers.
abstract: In the context of locally advanced oropharyngeal cancer (LAOC) treated with definitive radiotherapy (RT) (combined with chemotherapy or cetuximab), the aims of this study were: (1) to identify PET-FDG parameters correlated with overall survival (OS) from a first cohort of patients; then (2) to compute a prognostic score; and (3) finally to validate this scoring system in a second independent cohort of patients.
  
  
  
  A total of 76 consecutive patients (training cohort from Rennes) treated with chemoradiotherapy or RT with cetuximab for LAOC were used to build a predictive model of locoregional control (LRC) and OS based on PET-FDG parameters. After internal calibration and validation of this model, a nomogram and a scoring system were developed and tested in a validation cohort of 46 consecutive patients treated with definitive RT for LAOC in Lausanne.
  
  
  
  In multivariate analysis, the metabolic tumour volume (MTV) of the primary tumour and the lymph nodes were independent predictive factors for LRC and OS. Internal calibration showed a very good adjustment between the predicted OS and the observed OS at 24 months. Using the predictive score, two risk groups were identified (median OS 42 versus 14 months, p < 0.001) and confirmed in the validation cohort from Lausanne (median OS not reached versus 26 months, p=0.008).
  
  
  
  This is the first report of a PET-based nomogram in oropharyngeal cancer. Interestingly, it appeared stronger than the classical prognostic factors and was validated in independent cohorts markedly diverging in many aspects, which suggest that the observed signal was robust.
authors.affiliation: Radiotherapy Department, Lausanne University Hospital, Switzerland; INSERM, U1099, Rennes, F-35000, France; Université de Rennes 1, LTSI, Rennes, F-35000, France.
authors.forename: J
authors.initials: J
authors.lastname: Castelli
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, VD, Switzerland; University of Applied Sciences Western Switzerland, 3960, Sierre, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Depeursinge
authors.affiliation: Radiotherapy Department, Centre Eugene Marquis, Rennes, F-35000, France.
authors.forename: V
authors.initials: V
authors.lastname: Ndoh
authors.affiliation: Nuclear Medicine and Molecular Imaging Department, Lausanne University Hospital, Switzerland.
authors.forename: J O
authors.initials: JO
authors.lastname: Prior
authors.affiliation: Radiotherapy Department, Lausanne University Hospital, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Ozsahin
authors.affiliation: Nuclear Medicine Department, Centre Eugene Marquis, Rennes, F-35000, France.
authors.forename: A
authors.initials: A
authors.lastname: Devillers
authors.affiliation: Radiotherapy Department, Lausanne University Hospital, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Bouchaab
authors.affiliation: Radiotherapy Department, Centre Eugene Marquis, Rennes, F-35000, France.
authors.forename: E
authors.initials: E
authors.lastname: Chajon
authors.affiliation: Radiotherapy Department, Centre Eugene Marquis, Rennes, F-35000, France.
authors.forename: R
authors.initials: R
authors.lastname: de Crevoisier
authors.affiliation: Radiotherapy Department, Lausanne University Hospital, Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Scher
authors.affiliation: Head and Neck Department, CHU Rennes, Rennes, F-35000, France.
authors.forename: F
authors.initials: F
authors.lastname: Jegoux
authors.affiliation: Oncology Department, Centre Eugene Marquis, Rennes, F-35000, France.
authors.forename: B
authors.initials: B
authors.lastname: Laguerre
authors.affiliation: Radiotherapy Department, Lausanne University Hospital, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: De Bari
authors.affiliation: Radiotherapy Department, Lausanne University Hospital, Switzerland. Electronic address: Jean.Bourhis@chuv.ch.
authors.forename: J
authors.initials: J
authors.lastname: Bourhis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D016190:Carboplatin / Q000008:administration & dosage; D000068818:Cetuximab / Q000008:administration & dosage; D059248:Chemoradiotherapy / Q000379:methods; D002945:Cisplatin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049451:Nomograms; D009959:Oropharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods; D011379:Prognosis; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D055815:Young Adult
chemical_list: D016190:Carboplatin; D000068818:Cetuximab; D002945:Cisplatin
keywords: Nomogram; Oropharyngeal cancer; PET; Prognostic score