RESUMO
PURPOSE: To quantify radiation exposure of radiation therapy technologists (RTTs) in a proton treatment facility in comparison with a photon therapy facility, to inform and establish these specialized occupational safety guidelines. METHODS AND MATERIALS: Two groups of RTTs, consisting of 12 full-time passive scattering proton RTTs and 18 full-time conventional photon RTTs, wore an additional dosimetry badge at the waist for a period of 14 weeks. The 2 groups of RTTs were given identical instructions on the proper use of the badges. To compare exposures between passive scatter and scanning beam systems, exposure rates from activated equipment in both systems were measured. RESULTS: Over the 14-week period, the mean and standard deviation background-corrected dose for the passively scattered proton RTTs was 39.9 ± 5.4 mrem. The mean and standard deviation background-corrected dose for the conventional photon RTTs was similar at 39.9 ± 9.0 mrem (P = .6). Exposure rates were lower in equipment activated in a scanning beam system in comparison with those from a passive scatter system. CONCLUSIONS: Radiation dose to passively scattered proton and photon radiation therapy technologists was similar when measured with a dosimeter worn at the waist over a period of 14 weeks. On the basis of these data, the departmental policy permits pregnant radiation workers to work in proton treatment areas, and the policy for pregnant workers does not differ between proton and photon radiation workers or between passive scatter and scanning beam systems. All employees are encouraged to limit time near and proximity to activated equipment.
