C 52 GBZ GBZ/T 161 2004 Radiological protection and safety standards for medical Gamma-beam teletherapy 2004 5 21 2004 12 1 GBZ/T 161 2004 - 1 - 1 2 - 1 3 - 1 4 - 1 5 - 2 5.1 - 2 5.2 -2 5.3 - 3 6 - 3 6.1 - 3 6.2 - 3 6.3 - 3 7. - 4 7.1 - -4 7.2 - 4 8 -4 8.1 - 4 8.2 - 5 8.3 - 8 8.4 - 11 -13 B - 14 GBZ/T 161 2004 4-7 GB16351-1996 60 GBZ/T 161 2004 GBZ/T 161 2004 GBZ/T 161 2004 GBZ/T 161 2004 GBZ/T 161 2004 GBZ/T 161 2004