Research in Medicine

Background and Aim: Today, the treatment of prostate cancer and endocrine cancer by means of radiopharmaceuticals derived from lutetium-177 is the focus of many radionuclide therapy centers. One of the reasons for turning to lutetium radiopharmaceuticals is its favorable dosimetry and stability. Excreting the urine of these patients into the hospital's sewage and consequently into the city's sewage and finally into the agricultural fields causes indirect radiation exposure of the people. The aim of this study is to investigate the radiation exposure of people due to the presence of this radioactive material in urban areas.
Methods: In this cross- sectional study, the estimation of radioactivity in sewage has been done. In the first method, 18 wastewater samples were prepared in a standard volume from specific places at different times. The samples were counted using the gamma spectrometry method and the amount of radioactive substances in them was determined. In the second method, the concentration of radioactive substances in the wastewater was estimated using a mathematical model, and then the dose received by the people was calculated.
Results: The dose received by the people from lutetium the wastewater of Shahada Tajrish Hospital is estimated to be 0.00052 nanosieverts per year, so this amount is equal to 1.73E-9 of the annual permissible dose and is equivalent to 0.0000003 days of natural radiation exposure.
Conclusion: The amount of dose received by people from lutetium in the wastewater of Shohada Tajrish Hospital is very small and is much less than the annual limit. Therefore, the direct discharge of the urine of patients treated with lutetium into the sewage of the nuclear medicine department of the mentioned hospital during the quarantine period of the patient undergoing radiation treatment does not cause significant radiation to the public.