Systematic review of methodology used in clinical studies evaluating the benefits of proton beam therapy.

Proton beam therapy (PBT) delivers high-energy radiation to target tumours while sparing surrounding normal tissues. The dosimetric advantages of PBT over traditional photon radiotherapy may be clear but the translation of this benefit into clinically meaningful reductions in toxicities and improved quality-of-life (QoL) needs to be determined. Randomised controlled trials (RCTs) are considered the gold standard for generating the highest-level evidence in medicine. The objectives of this systematic review were to provide an overview of published clinical studies evaluating the benefits of PBT, and to examine the methodology used in clinical trials with respect to study design and outcomes.