These are most likely not canker sores (herpes simplex), but residual mucositis from the radiation treatments. Mine finally resolved about 8 weeks after the end of radiation. There is little that you can do to speed up their resolution. It is mostly about dealing with the discomfort until your body can repair itself. For me this meant pain meds and constant swishing of my mouth with baking soda and water. It just takes time....

Brian, stage 4 oral cancer survivor. OCF Founder and Director. The first responsibility of a leader is to define reality. The last is to say thank you. In between, the leader is a servant.