White spots

My brother is 28 years old and was diagnosed a year ago with stage four thyroid cancer.  Shortly after his diagnosis he went through a major surgery removing his thyroid, and hundreds of lymph nodes.  It had spread all the way through his sternum and metastisized outside of the actual tumor on his neck.  He also went through a bout of radiation.  At his one year mark after his surgery, they found it was back.  They have been monitoring his count before they can perform another surgery.  Today he had an appointment for his blood work results which had jumped from a six to twenty four in two months.  Once it hits forty, they said they will operate again.  They upped the dosage of his medication to 250, stating that 300 was the maximum they could up it to but would have to continue to up it as the cancer grows.  They sent him for a chest xray today since they were concerned it was spreading again.  He was given the films which show white spots on his rib cage as well as an elongated almost faded white spot down the backside.  He will get his results from that in ten days.  I do remember from his previous xray that his tumor showed up looking exactly the same as these spots appear.  Is this cause for concern and based on his history, does this mean we are looking at bad results?