If sirt is done for liver mets , can this significantly prolong survival in metastic colon cancer pt?

Yes: It is palliative not curative. The amount of life extension is based on each individual case

In the right patient: Yes, in the appropriate clinical setting of 2nd, 3rd line and salvage therapy. Selective internal radiation therapy (SIRT/Y-90) is recommended for chemorefractory disease with liver-only or liver-predominant disease & in people who do not wish to have systemic chemotherapy. Since the median survival in failed 3rd line chemo patients is in the range of 4-6 mth, SIRT can extend survival to 10-12 mth