Because this cryo method is minimaly invasive, it can be applied multiple times over a period of time until all the tumour is completely gone. The patient needs to be monitored periodically to check for any regrowth of the tumour.the cryoablation zone is divided into the central and the edge zone. in the central zone, tumor cells undergo coagulative necrosis. the body will take care of these dead cells. in the sublethal temperature zone at the edge of the ablation, tumor cells undergo apoptosis. unlike necrotic cells, apoptotic cells in the marginal area not only fail to stimulate an immune response but can also induce immune tolerance. so cryoablation is not going to remove the tumor completely