Hi papionsky1. Welcome to the forum.

I am not a doctor and I have no medical qualifications. 

It's always worrying to get a cancer diagnosis. I was diagnosed with prostate cancer 8 years ago and I had surgery to remove it.

Having a clear MRI and bone scan are both very reassuring indicators that your cancer is confined, but I'm afraid that a PSA of 112 is very high, and those two tests alone aren't sufficient to be certain. Hence the need for the PET scan.  

Many new patients (and quite a lot of us more experienced hands) fall into the trap of thinking that because a test is ordered, the doctors must be pretty certain that the result to be positive. In other words, we think that doctos only order tests to confirm their suspicions of a bad outcome.  Nothing could be further from the truth.  Most of the time tests when tests are ordered, the doctors have no expectations of what the result might be. Your PET test has been ordered because it's a sensible next step and the doctors genuinely don't know what it will show up. 

Please can you let us know how you get on.  We're all on your side and rooting for you. 

Thank you so much  for the reassurance. Fingers crossed, I await my appointment. 

Just to reinforce telemando......I certainly fell into the ".... the trap of thinking that because a test is ordered, the doctors must be pretty certain that the result to be positive. In other words, we think that doctos only order tests to confirm their suspicions of a bad outcome." a couple of weeks ago! Tongue cancer confirmed by biopsy and although head and neck MRI seemed entirely logical I was far more concerned by requested Thorax, Abdomen and Pelvis CT Scan. I did assume meant strong suspicions of extensive spreading, but apparently not the case. While some analysis not complete, no indications of migration. 

So.....good luck.