Projection of lifetime cancer risk from high-resolution chest CT using the LAR model in Fars Province, Iran, during the COVID-19 pandemic.
The study estimates a total LAR of 90 lung cancer cases per 100,000 persons due to HRCT exposure during the COVID-19 pandemic, highlighting the need for dose optimization in imaging protocols.
Where it sits
this study against the rest of the lanreotide corpusSummary and findings
The study estimates the Lifetime Attributable Risk (LAR) of certain cancers associated with high-resolution computed tomography (HRCT) in Fars Province, Iran. It analyzed data from 1,411 patients over a period from February 2020 to December 2022. The findings indicate varying LAR rates for different cancers per 100,000 persons.
Abstract
<h4>Purpose</h4>The study addresses concerns regarding the potential increase in cancer cases due to the widespread use of high-resolution computed tomography (HRCT) during the COVID-19 pandemic.<h4>Method</h4>It estimates the Lifetime Attributable Risk (LAR) of certain cancers associated with HRCT in Fars Province, Iran. The estimation is based on a cross-sectional analysis conducted at Namazi Hospital from February 2020 to December 2022. The study employed the Imaging Performance Assessment of CT Scanners (ImPACT) to estimate organ doses. Additionally, it applied the Biological Effects of Ionizing Radiation (BEIR) Committee models to calculate the Lifetime Attributable Risk (LAR) of cancer. A sensitivity analysis was also conducted to project the anticipated increase in radiation-induced cancers in the region.<h4>Results</h4>Out of 1,411 patients 754 (53.4%) were male, and their ages ranged from 15 to 95 years. 28% (395) had HRCT more than once (2 to 8 times). The mean and 95% uncertainty limits (UL) for total LAR of lung, thyroid, esophagus, stomach, liver, breast and Leukemia were 90 (95% UL, 80 - 116), 24 (95% UL, 18 - 33), 32 (95% UL, 26-39), 9 (95% UL, 8-11), 5 (95% UL, 4-6), 217 (95% UL, 194-244) and 30 ( 95% UL, 10-101) per 100,000 persons, respectively. The excess cancer burdens from radiation in Fars are estimated at approximately 55 years for solid cancers and 58 years for leukemia, with the following rates: lung 1.2%, thyroid 0.8%, breast 0.7%, esophagus 2.8%, stomach 0.1%, liver 0.9%, and leukemia 0.5%.<h4>Conclusion</h4>The widespread use of HRCT during the COVID-19 pandemic, while crucial for diagnosis and management, may increase the risk of radiation-induced cancers, especially among younger individuals and women. Key factors influencing this risk include repeated scans, younger age at exposure, and sex differences. Although the overall cancer burden from HRCT is low compared to baseline cancer incidence, dose optimization and ultra-low-dose protocols are essential to minimize harm.<h4>Supplementary information</h4>The online version contains supplementary material available at 10.1007/s40201-026-00987-z.
Background
This study addresses the potential increase in cancer risk due to high-resolution computed tomography (HRCT) during the COVID-19 pandemic. Prior knowledge indicates that radiation exposure from imaging can lead to increased cancer risk, but the specific impact of HRCT in this context was not well quantified. Understanding the Lifetime Attributable Risk (LAR) of cancers associated with HRCT is crucial for assessing public health implications.
Methods
The study utilized a cross-sectional analysis of 1,411 patients at Namazi Hospital from February 2020 to December 2022. It employed the Imaging Performance Assessment of CT Scanners (ImPACT) to estimate organ doses and the Biological Effects of Ionizing Radiation (BEIR) Committee models to calculate LAR. A sensitivity analysis was also conducted to project anticipated increases in radiation-induced cancers.
Results
The primary endpoint indicated a total LAR for lung cancer of 90 (95% UL, 80 - 116) per 100,000 persons. Other cancers had the following LARs: thyroid 24 (95% UL, 18 - 33), esophagus 32 (95% UL, 26 - 39), stomach 9 (95% UL, 8 - 11), liver 5 (95% UL, 4 - 6), breast 217 (95% UL, 194 - 244), and leukemia 30 (95% UL, 10 - 101). The study also reported excess cancer burdens of approximately 55 years for solid cancers and 58 years for leukemia.
Interpretation
The findings suggest that while the overall cancer burden from HRCT is low compared to baseline cancer incidence, the LAR values indicate a measurable risk, particularly for lung and breast cancers. The effect sizes, while statistically significant, may not be clinically meaningful given the low overall incidence rates. Limitations include the cross-sectional nature of the study and potential confounding factors, such as patient demographics and scan frequency.
Key findings
- Total LAR for lung cancer was 90 (95% UL, 80 - 116) per 100,000 persons.
- Total LAR for thyroid cancer was 24 (95% UL, 18 - 33) per 100,000 persons.
- Total LAR for esophageal cancer was 32 (95% UL, 26 - 39) per 100,000 persons.
- Total LAR for stomach cancer was 9 (95% UL, 8 - 11) per 100,000 persons.
- Total LAR for liver cancer was 5 (95% UL, 4 - 6) per 100,000 persons.
- Excess cancer burdens from radiation estimated at approximately 55 years for solid cancers and 58 years for leukemia.
Limitations
- cross-sectional design limits causal inference
- reliance on estimations for cancer risk
- no longitudinal data to assess actual cancer incidence
- potential confounding factors not fully addressed