iodine 131

half-life: 8 days
energy: 364 keV peak
beta emission ==> high thyroid dose (1 rad / uCi !!)
thyroid uptake (3 uCi)
used for treatment
- hyperthyroidism (2-30 mCi)
- thyroid Ca (150-200 mCi initially, up to 1Ci total)
whole-body imaging to F/U thyroid Ca after surgery