This is an established, one-day workshop on the use of radioiodine in the treatment of benign thyroid disease. The course represents an essential component of the national training scheme, aiming to allow application for ARSAC certification for iodine-131 administration for the treatment of benign thyroid disease. Other components of training, upon which guidance will be given and log books provided, will be locally arranged and include mentored experience of clinical cases as well as medical physics experience.