SIMPLE METHODS FOR THE ESTIMATION OF DOSE DISTRIBUTIONS, ORGAN DOSES AND ENERGY IMPARTED IN PEDIATRIC RADIOLOGY

The energy imparted and the effective dose can both be used to describ e the risk to the patient in diagnostic radiology. Simple methods must be employed to determine these quantities in clinical situations. Met hods using measured relative depth-dose distributions are presented an d evaluated here. Measurements of depth-dose distributions for x-ray b eams were performed with an ionization chamber, a diode and a number o f TL dosimeters. The energy imparted was calculated from measurements with both phantoms and patients. The method of calculating the mean ab sorbed dose to organs was applied to pelvis and lumbar spine examinati ons. TL dosimeters were found to be an appropriate detector for measur ing depth-dose distributions. When calculating the energy imparted the entrance beam area must be accurately known. The mean absorbed dose t o organs can be derived from measured relative depth-dose curves if ac curate information on entrance beam position and area is available for the particular examination technique used. The advantage of these met hods is that the dose distribution is measured for the photon beam use d for the examination of the patients.