1. a Department of Radiation Oncology, Hospital Sírio-Libanês, São Paulo, Brazil
2. c Department of Radiation Oncology, Instituto do Câncer do Estado de São Paulo, São Paulo, Brazil
3. b Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York, USA
4. d Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA