1 Department of Radiation Oncology, The Stanford University School of Medicine, Stanford, CA, USA.
2 Department of Occupational Health & Safety, Federal Ministry of Defense, Bonn, Germany; Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.
3 Department of Nuclear Medicine, University of Ankara, Ankara, Turkey.
4 Department of Nuclear Medicine, University Hospital Innsbruck, Innsbruck, Austria.
5 Department of Nuclear Medicine, Hacettepe University, Ankara, Turkey.
6 Department of Nuclear Medicine, Scintep, Institut Daniel Holland, Grenoble, France.
7 Center of Tobacco Control Research, Odense, Denmark. Electronic address: finn113edler@mail.tele.dk.