Yttrium-90 radioembolization of colorectal cancer liver metastases: a systematic review of clinical evidence

The present work aims to review the clinical evidence of survival outcome after treatment of colorectal cancer liver metastases using yttrium-90 radioembolization, existence, and relevance of clinical, imaging, and genomic predictors of treatment efficacy and the amount of administered activity. Publications listed in PubMed between July 2016 and May 2021 were screened. Predictors of overall survival were reported and distinguished in clinical, imaging, and genomic variables. Administered activity is reported as median and mean value; overall survival is presented as a median value from the treatment. Fourteen papers resulted to be eligible for this systematic review, 11 retrospective, and 3 prospective studies. Ten studies reported administered activity data, with an average mean administered activity of 1.63 GBq and an average median administered activity of 1.53 GBq. Many clinical, imaging and genomic variables have been identified or defined as predictors of efficacy, leading to the possibility of improvements in patient selection criteria. The overall survival resulted to be about 9 months. The clinical evidence on the application of radioembolization with yittrium-90 resumed in this work underlines the importance to analyze several clinical, imaging, and genomic variables to predict the outcome of the therapy. The overall survival has not improved significantly with respect to older studies. Further developments on treatment planning and patient selection could lead to better clinical outcomes