What does a thyroid iodine 123 tell?

I had a thyroid ultrasound done 1 month ago and it showed a mass on my left thyroid and multiple nodules on my right thyroid, o.k. doctor said he had to wait til this day to tell me the results cause he wanted to be sure first,o.k. i went back today and hehas scheduled for me to have a thyroid iodine 123 done tues. of next week.o.k. he told me that we couldn't rule out cancer,and he changed the subject real fast! i am really worried. so he gives me the order and i read it and it has on therecomplex cystic lesion ( with a c with a line over it )some internal hyperechogencity,saspicious lesion low pole left thyroid gland. can you please help me? they just told me to have he test done and nothing else. i am in the dark on this .what does all this mean,is it cancer or what.i have alot of trouble swallowing,and part of my left side of throat is dead.(( what does hyperechogencity and what does it have to do with my thyroid? will i have to have surgery? all that i have read on alot of these sites surgery of the thyroid is either part or all of the thyroid taken out. i am trying to get myself ready for anything. no matter what the outcome i want to be ready. can you please help at all. THANK YOU VERY MUCH AND ANY INFO IS APPREAITED!