Your "problem" is that all of your Drs. are correct. You are a good candidate for all three approaches. If you waited a couple of years, and went with surgery, you wouldn't be too old for surgery. If you waited for 10 years and got radiation you wouldn't have to worry about the rare, but horrific, brain cancers that could possibly result for radiation. If you had either treatment now, odds are, you'd come out fine.
The odds are against it, but it is not impossible that you could go year by year and see no growth, and eventually die of some other cause like heart disease etc. My father had treatment for his prostate cancer. He was just at that age where some Drs were telling him to just let it be, and others thought it was prudent to treat it. So, he went through real hell with the radiation treatments. They tore him up with pain and burning for a few months over the series of treatments. He had several procedures to help him urinate better, but ultimately had to use a catheter at least once a day for the rest of his life. They "cured" his prostate cancer, but he got pancreatic cancer and died at age 71. With 20/20 hindsight, he shouldn't have bothered with the prostate treatment. For all the grief it caused him, it added nothing to his longevity and actually decreased his quality of life.