Radiation exposure levels in diagnostic patients injected with 99mTc, 67Ga and 131I at the Mexican National Institute of Cancerology Nuclear Medicine Department

According to the Mexican Radiation Safety regulations for patients treated in a nuclear medicine service, the exposure rate limit at I m from the patients is 5 mR/h before leaving the hospital. Three groups of patients have been monitored after: a) whole body bone studies with 740 MBq of Tc-99m-MDP (207 patients); b) infection studies after i.v. administration of 185 MBq of Ga-67 (207 patients); and c) thyroid studies with 185 MBq of I-131 (142 patients). The results indicated that the average exposure rate levels in each group were: a) 0.57 +/- 0.17 mR/h, b) 0.47 +/- 0.20 mR/h, and c) 0.86 +/- 0.14 mR/h. This study has shown that the Nuclear Medicine Department at INCAN complies with the NOM-013-NUCL-1995 Mexican regulation.