Lung cancer screening with spiral CT.

Lung cancer is the main cause of death from malignancies due to the high prevalence and adverse prognosis when diagnosis is established in symptomatic patients. With early diagnosis, survival is far better; this led to perform some trials of screening in subjects at high risk with chest X-ray since 1970 but outcomes were contrasting. The technological evolution with the introduction of spiral CT and low dose techniques in the last decade led to a new interest in lung cancer screening. Numerous trials were performed and several diagnostic algorithms based on the dimensional and densitometric analysis of CT-evidenced nodules were designed. In spite of the encouraging outcome achieved so far, the high rate of false positives, the high costs and the use of ionizing radiation advise caution at least until a decreased mortality rate from lung cancer is evidenced.