France is on the cusp of launching a new pilot program for lung cancer screening, but the path to implementation has at times lagged behind other European countries. So just how have French radiologists caught up, and what steps will be taken over the next 12 months? Prof. Mathieu Lederlin, president of the Journées Francophones de Radiologie (JFR 25), revealed his views on the program’s organization and looks forward to when screening will reach the whole population.
Currently, with organized screening programs for the general population in breast, colorectal, and cervical cancer, France was relatively slow to react to evidence from established lung cancer screening trials such as NELSON and NLST.
A thoracic and cardiac radiologist, Prof. Mathieu Lederlin subspecializes in lung CT, particularly for interstitial lung diseases and lung cancer. He also performs cardiac CT and MRI, and emergency imaging. He is a member of the board of the national college of radiology (CERF) and former president of the French Society of Thoracic Imaging.
“For the past 10 years, French thoracic radiologists have been calling for lung cancer screening, but it took a while for politicians and organizations such as the country’s Academy of Medicine to wake up and realise that it could save a lot of lives. Fortunately, the European Commission got behind lung cancer screening two years ago, and this helped shift opposition from the health authorities and other institutions,” noted Lederlin, who is head of the thoracic and cardiovascular imaging department at the 1,800-bed Pontchaillou University Hospital in Rennes. “Now we have to make up for lost time.”
Covering all French regions, the complex pilot program, IMPULSION (IMplémentation du dépistage du cancer PULmonaire par Scanner en populatION), is an important preliminary step to validate several methodological points before rollout to the whole population.
Prof Mathieu Lederlin talks about the exciting road ahead for lung cancer screening in France. Videos produced by Christof.G.Pelz | GRAFIFANT Creation | www.grafifant.at | 2025
“If everything goes well, the pilot should evolve into a simplified mass population screening program in 3 to 5 years,” he added.
Training and collaboration
Lederlin outlined key factors that helped move the project forward, including the decision to start training radiologists early and to share leadership of the pilot program.
“The first step was that we did not wait for the approval of the program to train French radiologists in screening: Over the past four years, the French Society of Thoracic Imaging has set up training courses based on the European educational program, and we have trained more than 500 radiologists so far,” he noted. “Training comprises e-learning modules and one-day workshops to learn how to use lung nodule segmentation tools, and these workshops take place primarily in Paris around twenty times a year.”
Prof. Mathieu Lederlin runs a busy department with the help of colleagues such as technician Thierry Zimmer.
Another key step was to talk to the pulmonologists and to agree on a joint approach, which was not always easy, according to Lederlin. However, this collaboration was supported by the national cancer institute (INCa), which decided that the study would be a joint project between radiologists and pulmonologists.
Once the requirements, resources, and funding needed for the pilot program were defined, the project was approved by INCa at the start of 2025.
Optimizing strategies
The first IMPULSION study subjects from four regions will be included by the end of the year, with those from the rest of France joining in January, according to Lederlin, who is responsible for the radiology section of the project in Brittany and is currently developing a network of screening centers in the region. The goal is for 20,000 smokers across France to be screened over the next three years with low-dose CT, with a follow-up CT scan at one year, and then two years after this, at three years.
The pilot program will start with double reading of the CT scans, but after analyzing the first 2,500 scans, the goal is to move to single reading using AI, hopefully by early 2027, depending on the latter being at least as good as double reading, according to Lederlin.
Prof. Mathieu Lederlin and colleague Dr. Stéphanie Luzi discuss a case in the thoracic and cardiovascular imaging department of the cardio-pulmonary center at Pontchaillou University Hospital, Rennes.
The next step after this will be an intermediate analysis at three years to evaluate important criteria such as cancer detection rate, false positive rate, adherence rate, and the rate of incidental lesions, as well as the effectiveness of different invitation strategies.
Depending on results, the pilot study will gradually transition to mass population screening, possibly as early as 2029. The challenge then will be to scale up from 20,000 participants to potentially 3.8 million people.
Generation AI
He pointed to how AI solutions for CT were a must for lung cancer screening, particularly for detecting and characterizing nodules.
In Pontchaillou, as in many other university hospitals in France, radiologists use and evaluate several AI tools, both for performing simple tasks on complex exams, such as CT nodule detection, or complex tasks on simple exams, like interpreting chest x-rays, and the hospital has some collaborations with startups.
“For interpreting chest x-rays, AI is mainly used by young radiologists and residents. We have observed that the younger the radiologist, the more their performance is improved by AI, and the more they are reassured by its use,” he said.
When he is not performing cardio and thoracic CT and MRI, Lederlin is also an emergency radiologist and believes that one of the most promising future applications of AI will be for reading body scans performed in emergency rooms.
“There are a considerable number of items to check on emergency body scans, nothing very difficult, but it is a long checklist. I think it is typically in these detection tasks that AI could find very useful applications,” he noted.
Prof. Mathieu Lederlin discusses how he will bring his own touch to JFR 2025, which begins in Paris on 3 October.
Look out for Part 2 of the JFR 2025 interview next week. Our second article will focus on what's new at this year's congress.
