Over an average of 10.6 years of followup, the radiation-exposed group was more likely to: Have their thyroid removed (83 per cent versus 38 per cent in the group that wasn't exposed to radiation). Need more surgery (23 per cent versus two per cent). Have advanced stage IV disease (16 per cent versus five per cent). Have distant metastases, or spread far from the original site (nine per cent versus two per cent). Have thyroid cancer at followup (eight per cent versus three per cent). Have died of the disease (four per cent versus 1.5 per cent).