Radiation exposure around patients in nuclear medicine procedures

In this study, mean effective half-life was investigated by the measurement of radiation doses which is emitted to environment during the bone scintigraphy at Celal Bayar University Faculty of Medicine, Department of Nuclear Medicine. 7 prostate carcinoma, 5 breast carcinoma, 4 thyroid carcinoma and 14 others (traumatic/degenerative/infection) which are total of 30 (12 women,18 men "averaged men life is 52±14 years") were included in this study. The evaluation of radiation dosage rate is done with Geiger-Muller after the injection for every hours from the distance of 0, 0.5, 1, 1.5 and 2 meter from the patient in the position of abdomen line anterior (A), posterior (P), right lateral (RL) and left lateral (LL) up to 6th hour. For every patient, dosage rate/time trajectories were formed and their effective half-life values were calculated. According to the results, the mean effective half-life for the bone scintigraphy which is done by Tc-99m MDP, is 2.34±0.22 hour, 2.31±0.26 hour, 2.34±0.25 hour and 2.32±0.23 hour respectively, for the position of A, P, RL, LL. Furthermore, the mean effective half-life for the group of patients is calculated as 2.6±0.1 hour for prostate carcinoma , 2.1±0.04 hour for breast carcinoma, 2.3±0.2 hour for thyroid carcinoma and 2.2±0.2 hour for others. The result of the statistical evaluation with Kruskal Wallis variance analysis showed that the effective half-life for the patient who has a prostate carcinoma is longer than the patient who has a breast carcinoma, thyroid carcinoma and other groups, and it is meaningful for statistics. We think that this situation depends on the residual urine activity in bladder which is occured because of the non urinary drainage for the prostate carsinoma patients. According to the effective half-life of Tc 99m MDP and staying time in a hospital, it is thought that the protection is not required for the patient's relative, but it is required new protection steps for a medical staff in respect to patient groups.