1. Faculty of Medicine, American University of Beirut, Beirut 1107, Lebanon
2. Faculty of Medicine, University of Balamand, Beirut 1100, Lebanon
3. Memorial Sloan Kettering Cancer Center, New York, NY 10027, USA
4. Department of Surgery, Weill Medical College, Cornell University, New York, NY 10021, USA
5. Department of Medicine, Weill Medical College, Cornell University, New York, NY 10021, USA
6. New York Proton Center, New York, NY 10035, USA