title: An Excel-Based System to Manage Radiation Safety for the Family of Patients Undergoing131I Therapy.
abstract: The purpose of this study was to develop spreadsheet workbooks that assist in the radiation safety counseling of131I therapy patients and their families, providing individualized guidelines that avoid imposing overly conservative restrictions on family members and others.Methods:The mathematic model included biphasic patient radionuclide retention. The extrathyroidal component was a cylindric volume with a diameter corresponding to the patient's size and included patient self-absorption, whereas the thyroidal component was a point source whose transmission was reduced by self-absorption. A separate model in which the thyroid, extrathyroid, and bladder compartments fed serially from one to the next was developed to depict the radionuclide levels within the patient and to estimate the activity entering the environment at each urination.Results:The system was organized into a set of 4 workbooks: the first to be used with ablation patients prepared using thyrogen, the second with ablation patients prepared by deprivation, the third with hyperthyroid patients, and the fourth with the unusual hyperthyroid patient who finds the restrictions to be oppressive and returns 5-10 d after administration for a measurement and reassessment. The workbooks evaluated the radiation field strength external to the patient and indicated restrictions based on selected dose limits. To assist physicians in suggesting contamination precautions, the workbooks also evaluated the radioactivity present within the patient and the estimated discharge into the environment as a function of time.Conclusion:The workbooks that were developed assist the radiation safety counselor in individualizing radiation protection procedures for the family of patients undergoing131I therapy. The workbook system avoids overly conservative assumptions while permitting selection of appropriate dose limits for each individual.
authors.affiliation: Genesis Health System (retired), Davenport, Iowa psteward@earthlink.net.
authors.forename: Palmer G
authors.initials: PG
authors.lastname: Steward
mesh_terms: D001692:Biological Transport; D002648:Child; D005190:Family; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000378:metabolism / Q000627:therapeutic use*; D008954:Models, Biological; D011835:Radiation Protection; D012449:Safety; D012984:Software; D013964:Thyroid Neoplasms / Q000532:radiotherapy
chemical_list: D007457:Iodine Radioisotopes
keywords: 131I therapy; mathematical modeling; radiation protection; radiation safety; radiopharmaceutical therapy