7th Asia-Oceania Congress of Medical Physics and 13th CSMP Annual Meeting New Issues since NCRP 49 New types of equipment, Some with energies above 10 MV, Many new uses for radiotherapy equipment, Dual energy machines, Room designs without mazes, Varied shielding materials including composites, More published data on empirical methods. Instantaneous Dose Rate interpretation problemsNew Issues since NCRP # 49 – New types of equipment, – Some with energies above 10 MV, – Many new uses for radiotherapy equipment, – Dual energy machines, – Room designs without mazes, – Varied shielding materials including composites, – More published data on empirical methods. – Instantaneous Dose Rate interpretation problems 7 th Asia-Oceania Congress of Medical Physics and 13th CSMP Annual Meeting