Simultaneous integrated boost in paediatrics

The improvements, through intensity-modulated radiotherapy and inverse treatment planning, in dose conformity and spatially heterogenous dose distributions has pioneered the Simultaneous Boost Technique (SIB). SIB delivers differential dose levels to multiple target volumes within a single fraction, offering potential advantages over the traditional sequential boost (SEQB), including improved dose conformity, shorter overall treatment time, and simplified workflows. Over the past two decades, SIB has become standard in adult radiotherapy for several tumour sites and is increasingly applied in hypofractionated regimens, stereotactic ablative radiotherapy, and proton therapy. In paediatric radiotherapy, however, SIB implementation remains limited. Existing evidence is restricted to small studies demonstrating technical feasibility with photons and protons and suggesting potential benefits such as reduced normal-tissue dose and smaller planning margins. This work reviews the dosimetric and radiobiological differences between SEQB and SIB treatment planning techniques and outlines potential clinical applications of SIB for tumours in children and adolescents.