Radiation and thyroid cancer

With the disaster in Japan, people are desperately trying to find potassium iodine tablets to prevent thyroid cancer. Thyroid cancer patients are often told it is the 'good cancer'. I'm not kidding - we just want to slap those people.

But if you are going to get a cancer, thyroid cancer has a relatively good prognosis. Most thyroid cancers, except anaplastic which is always staged at IV due to its aggressiveness, are relatively slow growing. However once diagnosed it requires a lifetime of vigilance to ensure no recurrence as they have been known to occur as long as 45 years later.

I have been watching the news where in Japan there are dosing people with potassium iodine to prevent thyroid cancer. And the news in the US where there is a run on potassium iodine as well. Should I be concerned if thyroid cancer is the biggest risk? I know extreme exposure to radiation results in radiation sickness followed by organs dying off and then death of the patient. But if I already have had thyroid cancer and don't have a thyroid, is it a big deal? Since I don't have a thyroid would radiation go quicker to other organs? I don't know but I do know I don't need potassium iodine tablets. I'll go stock up on toilet paper instead.