[1] Friedrich Alexander Univ Erlangen Nurnberg FAU, Dept Radiat Oncol, Erlangen, Germany
[2] Friedrich Alexander Univ Erlangen Nurnberg FAU, Dept Surg, Erlangen, Germany
[3] Univ Freiburg, Dept Gen & Visceral Surg, Med Ctr, Freiburg, Germany
[4] Univ Freiburg, Fac Med, Freiburg, Germany
[5] Univ Hosp Magdeburg, Dept Surg, Magdeburg, Germany
[6] Univ Hosp RWTH Aachen, Dept Surg, Aachen, Germany
[7] Ruhr Univ Bochum, Dept Hematol Oncol & Palliat Care, St Josef Hosp, Bochum, Germany
[8] Univ Klinikum Frankfurt, Dept Radiat Oncol, Frankfurt, Germany
[9] Ludwig Maximilians Univ Munchen, Dept Med Oncol, Klinikum Grosshadern, Munich, Germany
[10] Ludwig Maximilians Univ Munchen, Ctr Comprehens Canc, Klinikum Grosshadern, Munich, Germany
[11] Clin Ctr Bayreuth, Dept Radiotherapy, Bayreuth, Germany
[12] Outpatient Dept Hematol Oncol, Friedrichshafen, Germany
[13] Frankfurt Univ Hosp & Clin, Dept Gen & Visceral Surg, Frankfurt, Germany
[14] Ruhr Univ Bochum, St Josef Hosp, Dept Surg, Bochum, Germany
[15] Friedrich Alexander Univ Erlangen Nurnberg FAU, Med Ctr Informat & Commun Technol, Erlangen, Germany
[16] Univ Erlangen Nurnberg, Dept Med Informat Biometry & Epidemiol, Waldstr 6, D-91054 Erlangen, Germany
[17] Georg August Univ Gottingen, Dept Gen Visceral & Pediat Surg, Med Ctr, Gottingen, Germany