Is thyroid cancer at the 4th stage or advanced stage curable if treatment continues?

My mother is suffering from thyroid cancer and she is at the 4th stage or advanced stage of cancer as per the doctors.Treatment is done at Tata Hospital,Mumbai,As per their given dates,She needs to take Iodine therapy but the dates for next dose given (everytime) from TATA are too long due to which the infections spreads faster and my mother falls sick hence would like to know where else radio iodine therapy is done so that my mother dont have to wait for too long for treatment and would also like to know whether its curable or not if treatment continues