The Saron trial involved 140 patients, all with between one and five tumours across three or fewer organs.
Participants were divided into two groups, with one receiving standard treatment and the other receiving high-dose radiotherapy to all known disease sites in addition to standard treatment.
Researchers found that the cancer remained stable for an average of 13.9 months in patients who underwent radiotherapy in comparison to just 8.9 months for those without it – an increase of 56%.
The results were presented at the European Society for Medical Oncology Congress 2026 in Madrid by chief investigator Dr Fiona McDonald, a consultant thoracic clinical oncologist at The Royal Marsden NHS Foundation Trust.
Dr McDonald, who is also leader of the thoracic radiotherapy group at the Institute of Cancer Research, London, said there had been limited randomised evidence about the benefits of adding radiotherapy until now, but the Saron trial has provided important data to suggest a “significant improvement” without compromising quality of life.
“[This study] is an exemplar of national collaboration and why these types of studies are crucial for informing personalised treatment approaches for patients.”