An artificial intelligence (AI) program can spot signs of lung cancer on CT scans a year before they can be diagnosed with existing methods, according to research presented at the European Respiratory Society International Congress. 
Lung cancer is the most common cause of cancer death with around 1.8 million lives lost around the world each year. Lung cancer is often diagnosed at a late stage when treatment is less likely to succeed.
Researchers hope that using AI to support lung cancer screening could make the process quicker and more efficient, and ultimately help diagnose more patients at an early stage.
Computerised tomography or CT scans are already used to spot signs of lung tumours, followed by a biopsy or surgery to confirm whether the tumour is malignant. But each scan involves an expert radiologist examining around 300 images and looking for signs of cancer that can be very small. Trials using CT scans to screen people with a high risk of lung cancer have shown promise, however screening is hampered by the practical difficulty of a radiologist reviewing each image, one at a time, to decide who needs further tests.
The new study was presented by Benoît Audelan, a researcher in the Epione project team of the Inria (France’s National Institute for Research in Digital Science and Technology) centre at Université Côte d'Azur. He worked with colleagues from the Université Côte d'Azur, Therapixel (a software company specialising in artificial intelligence for medical imaging) and the University Hospital of Nice.
The researchers trained their AI program using a set of CT scans from 888 patients that had already been examined by radiologists to identify suspicious growths.
Then they tested it on different set of 1179 patients who were part of a lung screening trial with three year follow-up, using CT scans that were taken in the last two years of the trial. These included 177 patients who were diagnosed with lung cancer via a biopsy after their final scan in the trial.
The program identified 172 of the 177 malignant tumours in those CT scans, meaning it was 97% effective in detecting cancers. The five tumours that the program missed were near the centre of the chest, where tumours are harder to distinguish from healthy parts of the body.
Researchers also tested the program on scans taken a year before the tumours were diagnosed in the same 1179 patients and it was able to identify 152 suspicious areas that were later diagnosed as cancer.