Abstract

Introduction
Palliative thoracic radiotherapy is widely used in stage IV non-small cell lung cancer (NSCLC). Historical fractionation studies demonstrated effective symptom control and improved survival at higher doses, but these were conducted before the advent of modern systemic therapies. Advances in radiotherapy planning and delivery now permit higher doses with reduced toxicity, yet no studies have evaluated the optimal timing, dose, or fractionation of palliative radiotherapy. To address this evidence gap, the NIHR-funded TOURIST platform study has been established. It will deliver a series of randomised controlled trials (RCTs) across scenarios where palliative radiotherapy is used in stage IV NSCLC. Two candidate-specific trials (CSTs) are currently open: PRINCE and QUARTZ LUNG.

Methods
TOURIST is a pragmatic, multi-centre, phase III platform trial design. It incorporates multiple CSTs, each conducted as a randomised controlled trial within the overarching framework. The design allows rapid initiation of new CSTs via amendment, leveraging pre-approved infrastructure and existing open sites. This structure facilitates systematic evaluation of multiple scenarios, including integration with systemic therapies, higher doses, and fractionation schedules. Endpoints across CSTs include quality of life (QoL), toxicity, overall survival (OS), and progression-free survival (PFS). Importantly, the Radiotherapy Trials Quality Assurance (RTTQA) Group provides oversight, facilitating radiotherapy approval and ensuring consistent treatment delivery across participating centres. Future Directions Several additional candidate-specific trials are currently in work-up, driving further development of the platform. Ideas are welcome, and collaborators are encouraged to contact the study team for further information. Newlung cancer radiotherapy trial proposals, including qualitative or quantitative and translational will be considered for inclusion in the TOURIST platform.

Disclosure
No significant relationship.