What Causes The Bulging In Front Of Ear Lobe Move To The Back?

I had thyroid and lymph cancer surgery followed by radioactive iodine and then I had a saleindoscopy. It s been 3 weeks and 1 side is fine and the other side has a bulging gland after I eat. The bulge has moved from the middle of my face near my ear lobe and now it s on my face behind my ear lobe. Why is this? Did it not work? Why did it change where it s bulging? When will we know if it worked or does this mean it didn t. Thank you!