Data-Driven De-escalation in Radiotherapy

Radiotherapy plays a critical role in breast cancer treatment, where treatment accuracy is essential to maximise tumour control while minimising radiation exposure to surrounding healthy tissues. Researchers at Gleneagles Hospital Penang are investigating whether local image-guided radiotherapy (IGRT) data can be used to establish evidence-based Planning Target Volume (PTV) margins tailored to institutional practice and patient populations. The study analysed treatment setup data from 159 breast cancer patients treated using both Three-Dimensional Conformal Radiotherapy (3D-CRT) and Volumetric Modulated Arc Therapy (VMAT). By evaluating systematic and random positioning variations during treatment, researchers assessed opportunities to optimise PTV margins while maintaining the geometric accuracy required for safe and effective radiotherapy delivery. The findings demonstrate the feasibility of reducing and standardising institutional PTV margins to 5 mm for both treatment techniques. This approach may help reduce unnecessary radiation exposure to surrounding organs at risk while maintaining treatment precision and supporting more efficient clinical workflows. The study contributes to ongoing efforts to advance data-driven radiotherapy, improve treatment quality and enhance outcomes for patients undergoing breast cancer treatment. The research has been accepted for presentation at the 37th Annual Scientific Congress of the Malaysian Oncological Society.