Ultra-low dose CT appears to effectively describe asbestos-related pleural and parenchymal changes and diseases, Australian researchers have concluded.
However the findings do not yet support the screening of all people who have been exposed to asbestos, said the authors led by Fraser Brims from the Sir Charles Gairdner Hospital in WA in their paper published in Respirology.
“Annual screening with low radiation dose computed tomography (LDCT) of high-risk subjects can produce a lung cancer stage downshift with a significant mortality reduction and acceptable cost effectiveness,” the study authors wrote. This practice was now recommended by several organisations and was approved for funding in the USA, they noted.
The current study involved 906 asbestos-exposed individuals taking part in the Western Australian Asbestos Review Programme.
Ultra-LDCT identified indeterminate lung nodules – defined as >50mm3 – in 8.5% of the cohort, a finding which the study authors noted was lower than many other CT studies. Of these, eight cases had confirmed lung cancer (0.88%).
Clinically important incidental findings were observed in 9.4% of the cohort, predominantly related to lower respiratory tract inflammation.
Just over a quarter (25.7%) of the study cohort had evidence of ‘definite’ interstitial lung disease.
“LDCT appears to be an acceptable modality to monitor asbestos-exposed individuals”, the study authors concluded.
However despite a comparable prevalence of lung cancer to other high risk-smoker-screening studies the findings do not yet support the screening of all asbestos-exposed populations, they said.
“Issues such as refining and describing those at high risk of lung cancer as well as ongoing concerns with recruitment, false positive findings and the health-care economic implications need to be better understood before wider programmes are adopted” they added.