Robyn:
I am sorry your dad got lung cancer again. Especially after 16 years....what a bummer! Treatments these days can hold the cancer at bay for a very long time.
I have just one lung now and I may have another tumor in my remaining lung. If it is the only place where the cancer is, I plan to have it removed by cyberknife. I think one would qualify for cyberknife if the tumor is smaller than 3 cm and there is just one. Beyond that, and they may not do it. So, if your dad's cancer is still contained in his lung, and it is not big yet,he might try cyberknife.
http://www.cyberknifesupport.org/forum/default.aspx?f=6