CALIBRATION OF SEMICONDUCTOR-DETECTORS FOR DOSE ASSESSMENT IN TOTAL-BODY IRRADIATION

The aim of this paper is to discuss the measurements carried out to im plement 'in vivo dosimetry' with EDP-30 diodes in total body irradiati on (TBI) techniques. Exit calibrations and calibrations behind cerrobe nd protection blocks showed the importance of calibrating diodes in al l relevant clinical conditions. Special attention was given to calibra tion of diodes behind cerrobend blocks. Dependence of the calibration factors on the thickness of the shielding blocks was, therefore, studi ed. This dependence was again studied after adding a wax cap to the di ode and when the ionisation chamber was placed at the same depth as th e measuring point of the diode. Temperature dependence in diode sensit ivity and dependence on accumulated dose for diodes response and for t emperature correction factors were also examined.