Ionizing radiation and volumetric mammographic density.

OBJECTIVES: Mammographic density (MD) refers to the percentage of dense tissue of an entire breast and was proposed to be used as a surrogate marker for breast cancer. High-dose ionizing radiation (IR) has been recognized as a breast cancer risk factor. The aim of our study was to investigate association between lifetime low dose ionizing radiation (LDIR) and MD. MATERIAL AND METHODS: A cross-sectional study included 467 women aged 40-60 years who underwent screening mammography in Lódz, Poland. The digital mammography examination of the breasts included both craniocaudal and mediolateral oblique views. The volumetric breast density (VBD) (%) and fibrograndular tissue volume (FG) (cm3) were determined based on the analysis of mammographic image ("for processing") using Volpara Imaging Software. The exposure to IR was estimated for each individual, based on the data from interviews about diagnostic or therapeutic medical procedures performed in the area of the neck, chest, abdomen and spine, which involved X-rays and γ rays and the data about the doses derived from literature. Linear and logistic regression were fitted with VBD and FG as the outcomes and organ breast dose, effective dose and number of mammographies as the determinants, adjusted for major confounders. RESULTS: The analyses showed no association between VBD or FG and the breast organ dose or the effective dose. The only significant finding observed concerned the association between the number of mammographies and the FG volume with ß coefficient: 0.028 (95% CI: 0.012-0.043), and predicted mean FG volume >13.4 cm3 among the women with >3 mammographies when compared to those with none. CONCLUSIONS: This study does not, in general, provide support for the positive association between LDIR and MD. The weak association of the FG volume with the number of mammographies warrants further verification in larger independent studies. Int J Occup Med Environ Health. 2022;35(5):635-49.

Occupational exposure to physicians working with a Zero-Gravity™ protection system in haemodynamic and electrophysiology labs and the assessment of its performance against a standard ceiling suspended shield.

A two centre clinical study was performed to analyse exposure levels of cardiac physicians performing electrophysiology and haemodynamic procedures with the use of state of the art Zero-Gravity™ radiation protective system (ZG). The effectiveness of ZG was compared against the commonly used ceiling suspended lead shield (CSS) in a haemodynamic lab. The operator's exposure was assessed using thermoluminescent dosimeters (TLDs) during both ablation (radiofrequency ablation (RFA) and cryoablation (CRYA)) and angiography and angioplasty procedures (CA/PCI). The dosimeters were placed in multiple body regions: near the left eye, on the left side of the neck, waist and chest, on both hands and ankles during each measurement performed with the use of ZG. In total 29 measurements were performed during 105 procedures. To compare the effectiveness of ZG against CSS an extra 80 measurements were performed with the standard lead apron, thyroid collar and ceiling suspended lead shield during CA/PCI procedures. For ZG, the upper values for the average eye lens and whole body doses per procedure were 4 µSv and 16 µSv for the left eye lens in electrophysiology lab (with additionally used CSS) and haemodynamic lab (without CSS), respectively, and about 10 µSv for the remaining body parts (neck, chest and waist) in both labs. The skin doses to hands and ankles non-protected by the ZG were 5 µSv for the most exposed left finger and left ankle in electrophysiology lab, while in haemodynamic lab 150 µSv and 17 µSv, respectively. The ZG performance was 3 times (p < 0.05) and at least 15 times (p < 0.05) higher for the eye lenses and thoracic region, respectively, compared to CSS (with dosimeters on the apron/collar). However, when only ZG was used slightly higher normalised doses were observed for the left finger compared to CSS (5.88e - 2 Sv/Gym2 vs. 4.31 e - 2 Sv/Gym2, p = 0.016). The study results indicate that ZG performance is superior to CSS. It can be simultaneously used with the ceiling suspended lead shield to ensure the protection to the hands as long as this is not obstructive for the work.

[New-old methods of reducing and monitoring x-ray exposure in the interventional radiology environment]. / Nowe-stare metody redukcji i monitoringu narazenia na promieniowanie rentgenowskie w srodowisku zabiegowym.

Ionizing radiation as a scientific achievement provides a variety of advantages, e.g., in the medical field. However, it also causes a risk of some illnesses, e.g., cataract or cancer. This results in the need to measure radiation doses and to reduce the unnecessary risk. There are 3 main methods of dose reduction, i.e., shortening the time of exposure, working as far as possible from the X-ray source, and using radioprotective shields. Together with the development of science and technology, dose reduction methods and radioprotection methods have also evolved. Besides improved shielding, the ergonomics is also more advanced, e.g., the zero-gravity shielding or light, and non-lead aprons. What is more, the awareness of using radiological protection and conducting the surgery in the safest way for both the staff and the patient is growing up. The goal of this article is to discuss the newest methods of radiation protection against the background of 3 main protection principles. Med Pr. 2021;72(1):49-59.