This review appraised the cost-utility analyses (CUAs) in terms of the methodology and quality for proton therapy. Having identified seven PBT CUA studies in adult disease, the review pointed out that health economic evaluations of PBT were based on the single arm studies or dose-response models derived from radiobiological and epidemiological studies.

These CUAs were lack of transparency (clarity in the description and assumptions of the model and identification of model inputs) and validity (how well the model reflects reality) which the external validation of the model outputs was absent. The review concluded that the transparency and external validation were key areas for improvement in future CUAs for PBT.