1. Department of Thoracic Surgery, West German Cancer Center, Medical Faculty, University Hospital Essen, Ruhrlandklinik, Tueschner Weg 40, 45239 Essen, Germany
2. Department of Medical Oncology, West German Cancer Center, Medical Faculty, University Hospital Essen, Hufelandstr. 55, 45147 Essen, Germany
3. Department of Radiation Oncology, West German Cancer Center, Medical Faculty, University Hospital Essen, Hufelandstr. 55, 45147 Essen, Germany
4. Department of Pneumology, Medical Faculty, University Hospital Essen, Hufelandstr. 55, 45147 Essen, Germany