Beam configuration and physical parameters of clinical high energy photon beam for total body irradiation (TBI).

Purpose: To start total body irradiation (TBI) treatments, physical parameters are measured for a magna field irradiation.

Methods And Materials: 6 MV photon beam from Clinac 600 CD linear accelerator (Varian, USA) with fully opened collimator at 45° and gantry at 270° provided a diamond shaped magna field with diagonal dimension 224 cm at 4.0 m source skin distance (SSD).