Delta radiomics: a systematic review

Background Radiomics can provide quantitative features from medical imaging that can be correlated with various biological features and clinical endpoints. Delta radiomics, on the other hand, consists in the analysis of feature variation at different acquisition time points, usually before and after therapy. The aim of this study was to provide a systematic review of the different delta radiomics approaches. Methods Eligible articles were searched in Embase, PubMed, and ScienceDirect using a search string that included free text and/or Medical Subject Headings (MeSH) with three key search terms: radiomics, texture, and delta. Studies were analysed using QUADAS-2 and the RQS tool. Results Forty-eight studies were finally included. The studies were divided into preclinical/methodological (five studies, 10.4%); rectal cancer (six studies, 12.5%); lung cancer (twelve studies, 25%); sarcoma (five studies, 10.4%); prostate cancer (three studies, 6.3%), head and neck cancer (six studies, 12.5%); gastrointestinal malignancies excluding rectum (seven studies, 14.6%), and other disease sites (four studies, 8.3%). The median RQS of all studies was 25% (mean 21% +/- 12%), with 13 studies (30.2%) achieving a quality score < 10% and 22 studies (51.2%) < 25%. Conclusions Delta radiomics shows potential benefit for several clinical endpoints in oncology (differential diagnosis, prognosis and prediction of treatment response, and evaluation of side effects). Nevertheless, the studies included in this systematic review suffer from the bias of overall low quality, so that the conclusions are currently heterogeneous, not robust, and not replicable. Further research with prospective and multicentre studies is needed for the clinical validation of delta radiomics approaches.

Automated summary

Background radiomics and delta radiomics play important roles in medical imaging, correlating with biological features and clinical endpoints, as well as analyzing feature variations. Studies were categorized by disease types, with an overall low quality assessment, leading to potentially inconsistent and unstable conclusions in the current literature. Prospective and multicenter studies are necessary for further clinical validation of delta radiomics approaches.