1. Department of Respiratory Diseases, Erasmus Medical Center, Postbus 2040, 3000 CA Rotterdam, The Netherlands
2. Department of Respiratory Diseases, Amphia Hospital, Molengracht 21, 4818 CK Breda, The Netherlands
3. Center for Optical Diagnostics and Therapy and Department of Radiation Oncology, Erasmus Medical Center, Dr. Molewaterplein 50, 3015 GE Rotterdam, The Netherlands