What, why, and when we image: considerations for diagnostic imaging and clinical research in the Children's Oncology Group.

Success in improving treatment outcomes in childhood cancer has been achieved almost exclusively through multicenter and multidisciplinary clinical and applied research over several decades. While biologically rational as well as empirical approaches have led to combination chemotherapy and multimodality approaches to therapy, which have given rise to evidence-based practice standards, similar scientific rigor has not always been as evidently applied to modalities utilized to assess initial disease burden and, more important, response to investigational approaches to therapy. As the empirical approach to therapeutic advances has likely maximized its benefit, future progress will require translation of biologic discovery most notably from the areas of genomics and proteomics. Hence, attempts to improve efficacy of therapy will require a parallel effort to minimize collateral damage of future therapeutic approaches, and such a parallel approach will mandate the continued dependence on advances in diagnostic imaging for improvements in staging methodologies to best define risk groups for risk-adjusted therapy. In addition, anatomic and functional assessment of response and surveillance for disease recurrence will require improved understanding of the biology as well as natural history of individual diseases, which one hopes will better inform investigators in designing trials. Clinical and research expertise is urgently needed in the selection of specific imaging studies and frequencies that best assess a response as well as to define disease-free intervals. Despite limited resources to develop sufficient infrastructure, emphasis on enabling early assessment of new technology to minimize risks associated with treatment advances and with those critical diagnostic and staging procedures must continue to be a focus of pediatric cancer clinical research.