For a solitary ≤3 cm HCC with aggressive biology (e.g., rising AFP or rapid growth), what biology thresholds (AFP level or doubling time) would make you favor ablative-intent Y90 over other liver- directed options despite small tumor size?

For best outcomes, I recommend either MWA or TARE for this solitary (< 3 cm) lesion based on location and ability to get complete necrosis. In our tumor board, we ask IR which technique will give them the best outcome and often times it depends on location and both may work. I would make sure you did appropriate staging and make sure there are no additional lesions or metastatic disease that you have missed if the AFP is rising significantly.