[1] Goethe Univ Frankfurt, Dept Radiotherapy & Radiat Oncol, D-60054 Frankfurt, Germany
[2] Univ Erlangen Nurnberg, Dept Radiat Therapy, D-91054 Erlangen, Germany
[3] Univ Erlangen Nurnberg, Dept Surg, D-91054 Erlangen, Germany
[4] Univ Zurich, Epidemiol Biostat & Prevent Inst, Zurich, Switzerland
[5] Univ Med Ctr Gottingen, Dept Radiotherapy, Gottingen, Germany
[6] Univ Med Ctr Gottingen, Inst Pathol, Gottingen, Germany
[7] Kliniken Maria Hilf GmbH Monchengladbach, Dept Hematol Oncol & Gastroenterol, Monchengladbach, Germany
[8] Goethe Univ Frankfurt, Dept Radiotherapy & Oncol, D-60054 Frankfurt, Germany
[9] Tumor Biol Ctr Freiburg, Freiburg, Germany
[10] Univ Med Ctr Gottingen, Dept Gen Visceral & Pediat Surg, Gottingen, Germany
[11] Univ Leipzig, Inst Pathol, D-04109 Leipzig, Germany