Precautions for certain categories of individuals in contact with a patient after radionuclide therapy

Patients undergoing radionuclide therapy with radiopharmaceuticals may become a radiation source of external exposure. Release of the patients requires strict abidance of radiation safety regulations to minimize exposure to individuals in contact with patient, especially children and pregnant women. The purpose of the current study was to determine precautions for patients after radionuclide therapy to limit the contact time with others and to develop guidelines to reduce doses to individuals in contact with patient. Two cases were considered for analysis: contact with young children and co-sleeping with partners. Determination of the necessary time limitations was performed using open-assessed publications and Monte Carlo calculations at different distances from the patient. The results showed that radionuclide therapy with 225Ac, 223Ra, 89Sr, and 90Y would not exceed the limit of 0.3 mSv to individuals in contact with patient after radionuclide therapy, even in the case of no precautions. However, for patients with 131I, 177Lu and 153Sm, precautions to limit the time of close contact with children and co-sleeping with partners are required. The suggested precautions ensure the radiation safety of individuals in contact with the patient after radionuclide therapy by limiting the exposure limits and allow patients to maintain social contacts, which is important for their rehabilitation.