State of the art: radiolabeled microspheres treatment for liver malignancies

Areas covered in this review: Data from recent relevant clinical trials with Y-90-RE are discussed, focusing on response rate assessments and treatment outcome. What the reader will gain: Current data show that Y-90-RE combined with radiosensitizing chemotherapy is a safe and efficient modality that extends the time to progression in liver mCRC and unresectable HCC, although no survival benefits have been demonstrated. The treatment response after Y-90-RE seems to be better assessed using metabolic response assessments with serial fluorodeoxyglucose positron emission tomography (FDG-PET) in cases of FDG-avid tumours than with morphological criteria measured on computed tomography or magnetic resonance imaging (RECIST or WHO trials). Predictive models using multimodality imaging approaches (PET-SPECT-CT image fusion algorithms) have been proposed to better select patients for Y-90-RE. The optimal routine role of radioembolization remains to be defined; the complexity and wide availability of available therapeutic alternatives confuses the role of a locoregional treatment in a generalized disease. Take home message: Y-90-RE is a safe and efficient treatment modality in salvage therapy of colorectal cancer metastatic to the liver and in unresectable HCC. However, it has still to find its place as a first- or second-line treatment of mCRC in combination with or as an alternative to available biological agents. The role of Y-90-RE in other solid tumour types metastatic to the liver is much more uncertain and investigations in clinical situations in which disease is strictly limited to the liver are required. Pretherapeutic work-up, initially developed to explore hepatic vasculature and to assess lung shunting, might be able to predict treatment outcome, allowing a better patient selection.