Hi, what are the advantages and disadvantages of iodine 131 in nuclear imaging? e.g. the cost and the abundance, the stability

I 131 for treatment: The 131 isotope of Iodine is used to treat thyroid nodules and cancers due to its long half life. It's pretty cheap, but is given as an in pt. so there is cost there. I 123 is often used for diagnosis. Also used is technetium 99m to assess blood flow to nodules. Most common thyroid screen is ultrasound. Occasionally MRI can be a good problem solver as well.