From what I’ve read both are options. There’s benefits to getting the immune system to target cancerous cells Such as ongoing protection. Directly killing the cells is a good way to reduce tumor mass by direct injection however. The first t-cell immune treatments almost killed the patients due to liver/kidney overload from cellular debris as the immune system reacted too strongly, so being able to in cull tumor mass in a controlled fashion likely has merit as well. Either way the “detection method” would need to be very well tested and robust I imagine. Though the first treatments could be for “last chance” treatments that’d enable testing the safety of the particular detection method.