[1] Univ Hosp Frankfurt, Dept Radiotherapy, Frankfurt, Germany
[2] German Canc Res Ctr, DKFZ, Heidelberg, Germany
[3] German Canc Consortium, DKTK, Frankfurt, Germany
[4] Univ Hosp Zurich, Dept Radiat Oncol, Zurich, Switzerland
[5] Univ Hosp Frankfurt, Dept Med Hematol & Oncol, Frankfurt, Germany
[6] Univ Hosp Frankfurt, Frankfurt Canc Inst, Frankfurt, Germany
[7] Univ Hosp Frankfurt, Dept Otorhinolaryngol, Frankfurt, Germany
[8] Univ Hosp Frankfurt, Dept Oral Maxillofacial & Facial Plast Surg, Frankfurt, Germany
[9] Univ Hosp Frankfurt, Senckenberg Inst Pathol, Frankfurt, Germany
[10] Univ Hosp Frankfurt, Dept Diagnost & Intervent Radiol, Frankfurt, Germany