Data on occupational radiation exposure from nuclear medicine procedures for the time period of the 1950s through the 1970s is important for retrospective health risk studies of medical personnel who conducted those activities. However, limited information is available on occupational exposure received by physicians and technologists who performed nuclear medicine procedures during those years. To better understand and characterize historical radiation exposures to technologists, the authors collected information on nuclear medicine practices in the 1950s, 1960s, and 1970s. To collect historical data needed to reconstruct doses to technologists, a focus group interview was held with experts who began using radioisotopes in medicine in the 1950s and the 1960s. Typical protocols and descriptions of clinical practices of diagnostic radioisotope procedures were defined by the focus group and were used to estimate occupational doses received by personnel, per nuclear medicine procedure, conducted in the 1950s to 1960s using radiopharmaceuticals available at that time. The radionuclide activities in the organs of the reference patient were calculated using the biokinetic models described in ICRP Publication 53. Air kerma rates as a function of distance from a reference patient were calculated by Monte Carlo radiation transport calculations using a hybrid computational phantom. Estimates of occupational doses to nuclear medicine technologists per procedure were found to vary from less than 0.01 μSv (thyroid scan with 1.85 MBq of administered 131I-iodide) to 0.4 μSv (brain scan with 26 MBq of 203Hg-chlormerodin). Occupational doses for the same diagnostic procedures starting in the mid-1960s but using 99mTc were also estimated. The doses estimated in this study show that the introduction of 99mTc resulted in an increase in occupational doses per procedure.
*Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 9609 Medical Center Drive, Bethesda MD 20892; †Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN 37232; ‡Radiology and Nuclear Medicine Service, New Mexico VA Health Care System, 1501 San Pedro Blvd SE, Albuquerque, NM 87108; §National Council on Radiation Protection and Measurements, Bethesda, MD; **Retired; ††New York Presbyterian Hospital, Weill Cornell Medical Center, Starr 2‐21, Nuclear Med Department, 525 East 68th Street, New York, NY 10065; ‡‡Nuclear Medicine and Radiation Service, Department of Veterans Affairs Health System, 2215 Fuller Road, Ann Arbor, MI 48105; §§Department of Veterans Affairs Health System, Palo Alto, CA; ***National Institute of Biomedical Imaging and Biomedical Engineering, NIH, DHHS, 6707 Democracy Blvd, Bethesda, MD 20892; †††Johns Hopkins University Medical Center, Baltimore, MD 21287 (deceased); ‡‡‡Department of Radiology and Imaging Sciences, NIH Clinical Center, 10 Center Drive, Bethesda, MD 20892; §§§Departments of Nuclear Medicine, Tennessee Valley Healthcare System, Department of Veterans Affairs, 1310 24th Avenue South, Nashville, TN 37212; ****Institute of Radiation Protection and Dosimetry, Av Salvador Allende S/N, Recreio dos Bandeirantes, Rio de Janeiro, RJ 22780‐160 Brazil.
The authors declare no conflicts of interest.
For correspondence contact: Vladimir Drozdovitch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 9609 Medical Center Drive, Room 7E548, MSC 9778, Bethesda, MD 20892‐9778, or email at firstname.lastname@example.org.
(Manuscript accepted 21 January 2014)