Are Antimony-Bismuth Aprons as Efficient as Lead Rubber Aprons in Providing Shielding against Scattered Radiation?

AIM: The aim of this study is to compare the absorption ability of two lead-free aprons with a lead apron. METHOD: The absorption ability of three aprons was measured and compared; Opaque Fusion 0.35 mm (OpaqFu) bilayer apron containing bismuth and antimony, No Lead 0.35 mm (NoLead) one-layer apron containing antimony, and a lead apron. The measurements were repeated with and without each of the aprons present in both primary and scattered beams. The selected tube voltages were between 60 and 113 kVp with constant mAs, a fixed field size, and fixed source-to-object distance. RESULTS: No significant difference in absorption ability of the two lead-free aprons compared with that of the lead apron was observed when the dose was measured in the primary beam. When measurements were performed in the scatter radiation field, the absorption ability of the OpaqFu apron was 1.3 times higher than that of NoLead apron and nearly equal to the absorption ability of the lead apron. An increase in the difference between the OpaqFu and NoLead aprons was observed for the tube energies higher than 100 kVp in favour of OpaqFu apron. CONCLUSION: It is safe to use the lead-free aprons that were tested in this study in a clinical environment for the tube energy range of 60 kVp-113 kVp.

The risk of radiation-induced breast cancers due to biennial mammographic screening in women aged 50-69 years is minimal.

BACKGROUND: The main aim of mammographic screening is to reduce the mortality from breast cancer. However, use of ionizing radiation is considered a potential harm due to the possible risk of inducing cancer in healthy women. PURPOSE: To estimate the potential number of radiation-induced breast cancers, radiation-induced breast cancer deaths, and lives saved due to implementation of organized mammographic screening as performed in Norway. MATERIAL AND METHODS: We used a previously published excess absolute risk model which assumes a linear no-threshold dose-response. The estimates were calculated for 100,000 women aged 50-69 years, a screening interval of 2 years, and with an assumed follow-up until the age of 85 or 105 years. Radiation doses of 0.7, 2.5, and 5.7 mGy per screening examination, a latency time of 5 or 10 years, and a dose and dose-rate effectiveness factor (DDREF) of 1 or 2 were applied. RESULTS: The total lifetime risk of radiation-induced breast cancers per 100,000 women was 10 (95% CI: 4-25) if the women were followed from the ages of 50 to 85 years, for a dose of 2.5 mGy, a latency time of 10 years, and a DDREF of 1. For the same parameter values the number of radiation-induced breast cancer death was 1 (95% CI: 0-2). The assumed number of lives saved is approximately 350. CONCLUSION: The risk of radiation-induced breast cancer and breast cancer death due to mammographic screening is minimal. Women should not be discouraged from attending screening due to fear of radiation-induced breast cancer death.