Janice

Hard choices. I'm biased in favor of a second round of radiation because it appears to have worked for me. I asked my RO the exact same question: Why would radiation work now when it failed me before? His answer was that some cancer cells are radiation resistant and they are the ones that came back. However the focus of the CyberKnife would let him pump more rads in at a time at a much higher intensity which should overwhelm even these cells. I averaged 2 GYs each of my 40 IMRTs, while the tumor that came back got a whopping 5 GYs each and every one of my 5 Cyberknife TXs
Also I don't know what you are hearing about complications shortening his life so I can't address them specifically. I'd be very surprised if whatever they were, they shortened Mike's life more than not getting radiation and letting this cancer continue to grow. Radiation complications are "funny" in that the longer you live, the more likely you will get them.
When you do your final risk analysis, if there is a "fair" chance that the radiation would "work", IMO that's a chance worth taking.
Hope Mike recovers from the pneumonia soon
Charm