Lifetime Attributable Risk for Breast Cancer Induced by High-Resolution Computed Tomography During COVID-19 Pandemic

Area of Science:

• Radiology and Imaging
• Oncology
• Public Health

Background:

• The COVID-19 pandemic led to increased use of high-resolution computed tomography (HRCT) for diagnosis and management.
• Concerns have arisen regarding the potential long-term impact of this increased radiation exposure on future breast cancer incidence.

Purpose of the Study:

• To estimate the Life Attributable Risk (LAR) of breast cancer associated with HRCT utilization during the COVID-19 pandemic in Shiraz, Iran.
• To provide data that can inform radiation safety protocols and clinical decision-making.

Main Methods:

• A cross-sectional study was conducted at Namazi Hospital, Shiraz, from February 2020 to December 2022.
• Organ doses were calculated using the Imaging Performance Assessment of CT Scanners (ImPACT) patient dosimetry calculator.
• Life Attributable Risk (LAR) was computed using the Biological Effects of Ionizing Radiation (BEIR) Committee models.

Main Results:

• The study included 666 participants aged 15-95 years.
• 25% of participants underwent HRCT more than once (2-8 times).
• The mean Total LAR of breast cancer was estimated at 217 per 100,000 persons (95% Uncertainty Limits: 194-244), considering single and multiple exposures.

Conclusions:

• The findings highlight a non-negligible risk of radiation-induced breast cancer following HRCT.
• Recommendations include prioritizing ultra-low-dose protocols over low-dose protocols for HRCT.
• Clinicians are advised to avoid unnecessary and repeated chest HRCT requests within short intervals to minimize cumulative radiation exposure.