I was diagnosed with pancreatic cancer 9/12/2016 Stage 3. I was told I'm not a candidate for surgury. Dr been giving me chemo and until now the tumor was stable. Now the last abd cat scan shows there's a 'mild progression of the tumor at the head of the pancreasl Drs want me to have radiation ; and and I'm scheduled for a PET SCAN in the morning. How effective is radiation..and I was told I MUST keep my blood sugar UNDER 150 IN ORDER TO HAVE THE pet scan. My blood sugars have always been erratiC; wILL they NOT DO THE TEST IF MY BS ISN'T BELOW 150 which means I can't do the radiation?